Develop Reference

My button for changing activity is not working

So....i am trying to make this button change from main activity to Disciplinas_Activity. But whenever I try to run the app and click the button, the app crashes.
Keep in mind i have other 3 button completly identical ,(other then the fact that they direct to different activities), in the same activity and they all work with the same base code.
Here is the .xml code for Main Activity
<TextView
android:id="#+id/textView_emailnotverified"
android:layout_width="172dp"
android:layout_height="34dp"
android:background="#color/white"
android:text="Email não Verificado!"
android:textColor="#E41F1F"
android:textSize="18dp"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.066"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.516" />
<TextView
android:id="#+id/textView_studentEmail"
android:layout_width="237dp"
android:layout_height="40dp"
android:text="Email do aluno"
android:textColor="#color/white"
android:textSize="18dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.856"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.395" />
<ImageView
android:id="#+id/imageView4"
android:layout_width="332dp"
android:layout_height="168dp"
android:scaleX="2"
android:scaleY="1.3"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.493"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.028"
app:srcCompat="#drawable/etpr" />
<TextView
android:id="#+id/welcommingtextview5"
android:layout_width="337dp"
android:layout_height="39dp"
android:text="ESCOLA TÉCNICA E PROFISSIONAL DO RIBATEJO"
android:textAlignment="center"
android:textColor="#color/white"
android:textSize="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.459"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.15" />
<TextView
android:id="#+id/ETPRTitle5"
android:layout_width="258dp"
android:layout_height="30dp"
android:text="BEM-VINDO À ETPR"
android:textAlignment="center"
android:textColor="#color/white"
android:textSize="24dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.496"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.105" />
<Button
android:id="#+id/Button_LOGOUT"
android:layout_width="114dp"
android:layout_height="59dp"
android:text="Logout"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.934" />
<Button
android:id="#+id/button_Testes"
android:layout_width="108dp"
android:layout_height="47dp"
android:text="Testes"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.867"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.644" />
<Button
android:id="#+id/button_pdf"
android:layout_width="121dp"
android:layout_height="41dp"
android:text="PDF"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.894"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.753" />
<Button
android:id="#+id/button_historia"
android:layout_width="191dp"
android:layout_height="47dp"
android:text="Sobre o criador"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.149"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.76" />
<ImageView
android:id="#+id/imageView_perfil"
android:layout_width="122dp"
android:layout_height="118dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.055"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.376"
app:srcCompat="#mipmap/ic_launcher" />
<TextView
android:id="#+id/textView_studentname"
android:layout_width="236dp"
android:layout_height="33dp"
android:text="Nome do aluno"
android:textColor="#color/white"
android:textSize="18dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.857"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.329" />
<Button
android:id="#+id/button_emailverification"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Verificar agora"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.88"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.527" />
<Button
android:id="#+id/changeprofileBTN"
android:layout_width="245dp"
android:layout_height="41dp"
android:text="Mude a imagem de perfil"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.897"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.453" />
<Button
android:id="#+id/button_disciplinas"
android:layout_width="194dp"
android:layout_height="55dp"
android:text="Disciplinas"
android:clickable="true"
android:focusable="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.106"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.644" />
Here is my .java code for main activity
public class MainActivity extends AppCompatActivity {
TextView fullname, email, verifymessage;
FirebaseAuth fAuth;
FirebaseFirestore fstore;
String userID;
Button resendVerification, LogoutBTN, changeprofileBTN, tests, createrInfo, pdfdatabase, buttonDisciplinas;
ImageView profileImage;
StorageReference storageReference;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fullname = findViewById(R.id.textView_studentname);
email = findViewById(R.id.textView_studentEmail);
LogoutBTN = (Button) findViewById(R.id.Button_LOGOUT);
tests =(Button) findViewById(R.id.button_Testes);
createrInfo =(Button) findViewById(R.id.button_historia);
pdfdatabase =(Button) findViewById(R.id.button_pdf);
buttonDisciplinas = findViewById(R.id.button_disciplinas);
buttonDisciplinas.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, Disciplinas_Activity.class));
}
});
tests.setOnClickListener(new View.OnClickListener() {// menu dos testes
#Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),Testes_Activity.class));
}
});
createrInfo.setOnClickListener(new View.OnClickListener() {//página sobre a história da app
#Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),AboutMe_Activity.class));
}
});
pdfdatabase.setOnClickListener(new View.OnClickListener() {//pdf database
#Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),PDF_Activity.class));
}
});
LogoutBTN.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseAuth.getInstance().signOut();
startActivity(new Intent(getApplicationContext(),LoginScreen.class));
finish();
}
});
profileImage = findViewById(R.id.imageView_perfil);
changeprofileBTN = findViewById(R.id.changeprofileBTN);
fAuth = FirebaseAuth.getInstance();
fstore = FirebaseFirestore.getInstance();
storageReference = FirebaseStorage.getInstance().getReference();
StorageReference profileRef = storageReference.child("utilizadores/"+fAuth.getCurrentUser().getUid()+"/perfil.jpg");
profileRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
#Override
public void onSuccess(Uri uri) {
Picasso.get().load(uri).into(profileImage);
}
});
resendVerification = findViewById(R.id.button_emailverification);
verifymessage = findViewById(R.id.textView_emailnotverified);
userID = fAuth.getCurrentUser().getUid();
DocumentReference documentReference = fstore.collection("utilizadores").document(userID);
documentReference.addSnapshotListener(this, new EventListener<DocumentSnapshot>() {
#Override
public void onEvent(#Nullable DocumentSnapshot documentSnapshot, #Nullable FirebaseFirestoreException error) {
fullname.setText(documentSnapshot.getString("NomeCompleto"));
email.setText(documentSnapshot.getString("Email"));
}
});
FirebaseUser user = fAuth.getCurrentUser();
if (!user.isEmailVerified()){
verifymessage.setVisibility(View.VISIBLE);
resendVerification.setVisibility(View.VISIBLE);
resendVerification.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
user.sendEmailVerification().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Toast.makeText(v.getContext(),"Email de verificação enviado.", Toast.LENGTH_SHORT).show();
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.d("tag","Erro: Email de verificação não enviado " + e.getMessage());
}
});
}
});
}
changeprofileBTN.setOnClickListener(new View.OnClickListener() { //mudar imagem de perfil
#Override
public void onClick(View v) {
Intent openGalleryIntent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(openGalleryIntent,1000);
}
});
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1000 ){
if (resultCode == Activity.RESULT_OK){//se o resultado for igual então abre galeria
Uri imageUri = data.getData();
//profileImage.setImageURI(imageUri); //insere imagem escolhida na galeria
uploadImageToFirebase(imageUri);
}
}
}
private void uploadImageToFirebase(Uri imageUri) { //upload da imagem para base de dados
StorageReference fileReference = storageReference.child("utilizadores/"+fAuth.getCurrentUser().getUid()+"/perfil.jpg");
fileReference.putFile(imageUri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
#Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
fileReference.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
#Override
public void onSuccess(Uri uri) {
Picasso.get().load(uri).into(profileImage);
}
});
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Toast.makeText(MainActivity.this,"Erro", Toast.LENGTH_SHORT).show();
}
});
}
}
Here is .xml code for DisciplinasActivity
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/Relative_Layout_Title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="32dp"
android:layout_marginRight="20dp">
<TextView
android:id="#+id/Menu_Title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Disciplinas"
android:textColor="#color/white"
android:textSize="22sp">
</TextView>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/Menu_Title"
android:layout_marginTop="6dp"
android:text="ETPR"
android:textColor="#color/white"
android:textSize="14sp">
</TextView>
<TextView
android:id="#+id/Name_Data"
android:textColor="#color/white"
android:textSize="16sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toStartOf="#id/user_icon"
android:text="Nome">
</TextView>
<TextView
android:id="#+id/Email_Data"
android:textColor="#color/white"
android:textSize="16dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/Name_Data"
android:layout_toStartOf="#id/user_icon"
android:text="Email">
</TextView>
<ImageView
android:id="#+id/user_icon"
android:layout_width="62dp"
android:layout_height="62dp"
android:layout_alignParentRight="true"
app:srcCompat="#drawable/cara">
</ImageView>
</RelativeLayout>
<GridLayout
android:id="#+id/MainGrid"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="#+id/Relative_Layout_Title"
android:alignmentMode="alignMargins"
android:columnCount="2"
android:columnOrderPreserved="false"
android:rowCount="2">
<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_rowWeight="1"
android:layout_columnWeight="1"
android:layout_margin="12dp"
android:layout_marginTop="70dp"
app:cardCornerRadius="12dp"
app:cardElevation="6dp">
<LinearLayout
android:id="#+id/LinearLayoutSdac"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:orientation="vertical"
android:padding="16dp">
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_gravity="center"
android:src="#drawable/sdac_icon"/>
<TextView
android:layout_width="56dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="12dp"
android:text="SDAC"
android:textColor="#color/black"
android:textSize="18sp">
</TextView>
</LinearLayout>
</androidx.cardview.widget.CardView>
<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_rowWeight="1"
android:layout_columnWeight="1"
android:layout_margin="12dp"
android:layout_marginTop="70dp"
app:cardCornerRadius="12dp"
app:cardElevation="6dp">
<LinearLayout
android:id="#+id/LinearLayoutEletronica"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:orientation="vertical"
android:padding="16dp">
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_gravity="center"
android:src="#drawable/eletronica_icon"
app:srcCompat="#drawable/eletronica_icon" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="12dp"
android:text="Eletrónica"
android:textColor="#color/black"
android:textSize="18sp"/>
</LinearLayout>
</androidx.cardview.widget.CardView>
<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_rowWeight="1"
android:layout_columnWeight="1"
android:layout_margin="12dp"
android:layout_marginTop="70dp"
app:cardCornerRadius="12dp"
app:cardElevation="6dp">
<LinearLayout
android:id="#+id/LinearLayoutCD"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:orientation="vertical"
android:padding="16dp">
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_gravity="center"
android:src="#drawable/cd_icon"
app:srcCompat="#drawable/cd_icon" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="12dp"
android:text="CD"
android:textColor="#color/black"
android:textSize="18sp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_rowWeight="1"
android:layout_columnWeight="1"
android:layout_margin="12dp"
android:layout_marginTop="70dp"
app:cardCornerRadius="12dp"
app:cardElevation="6dp">
<LinearLayout
android:id="#+id/LinearLayoutIMEI"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:orientation="vertical"
android:padding="16dp">
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_gravity="center"
android:src="#drawable/imei_icon"
app:srcCompat="#drawable/imei_icon" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="12dp"
android:text="IMEI"
android:textColor="#color/black"
android:textSize="18sp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
</GridLayout>
<Button
android:id="#+id/ExitButton"
android:layout_marginTop="20dp"
android:layout_width="121dp"
android:layout_height="69dp"
android:layout_gravity="center"
android:layout_marginBottom="#+id/RelativeLayout"
android:text="Sair"
android:textColor="#color/white"
android:textSize="16dp" />
</LinearLayout>
Here is my .Java code for DisciplinasActivity
public class Disciplinas_Activity extends AppCompatActivity {
GridLayout gridPrincipal;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_disciplinas);
gridPrincipal = (GridLayout)findViewById(R.id.MainGrid); //identifica qual a grelha
//ação
setSingleEvent(gridPrincipal);
}
private void setSingleEvent(GridLayout gridPrincipal) {
for (int i =0;i<gridPrincipal.getChildCount();i++)
{
CardView cardView = (CardView)gridPrincipal.getChildAt(i);
final int finalI = i;
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),TeacherLoginScreen.class));//muda para Disciplina de Sdac
}
});
}
}
}
What am i missing...? if all the other 3 buttons work...why doesnt this one work? (I am a total newbie but i
I really need the help)

Consider your code
button = (Button)findViewById(R.id.button1);
You do not need to explicitly cast widgets anymore unless it's a special case like a RadioButton from a resource ID.
Please check that the button you're clicking is actually the button you set all this up for.
Add
android:clickable="true";
android:focusable="true";
to your buttons in the XML layout.
I'm guessing ConstraintLayout is creating this problem, you shouldn't come across this issue if you use LinearLayout.

In your .xml code for DisciplinasActivity you have some mistakes on the dimensions that you are using:
<GridLayout
...
android:id="#+id/MainGrid"
...
android:layout_marginBottom="#+id/Relative_Layout_Title" <!-- E.G 20dp -->
>
<Button
android:id="#+id/ExitButton"
...
android:layout_marginBottom="#+id/RelativeLayout" <!-- E.G 20dp -->
... />
For margins, padding, etc you have to use a dimension, like dp,in,mm,etc not a reference to other view, or you could use dimmens.xml maybe you are confusing android:layout_marginBottom with android:layout_constraintBottom_toBottomOf or another property. Check for this in all the elements in your .xml
This answer is due to this log that you posted:
ComponentInfo{studying.app.tkappv6/studying.app.tkappv6.Disciplinas_Activity}:
java.lang.UnsupportedOperationException: Can't convert to dimension:
type=0x12

In the MainActivity
Change the to "v.getContext()" istead of "MainActivity.this"
tests.setOnClickListener(new View.OnClickListener() {// menu dos testes
#Override
public void onClick(View v) {
startActivity(new Intent(v.getContext(), Testes_Activity.class));
}
});
createrInfo.setOnClickListener(new View.OnClickListener() {//página sobre a história da app
#Override
public void onClick(View v) {
startActivity(new Intent(v.getContext(), AboutMe_Activity.class));
}
});
pdfdatabase.setOnClickListener(new View.OnClickListener() {//pdf database
#Override
public void onClick(View v) {
startActivity(new Intent(v.getContext(),PDF_Activity.class));
}
});
LogoutBTN.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseAuth.getInstance().signOut();
startActivity(new Intent(v.getContext(),LoginScreen.class));
finish();
}
});
I was Looking into the code and i've never used this method, but it's strange for me so it's good to pay attention, I think is wrong to set a "Void", if the method is not going to receive any value, but since is a #Override method if it was that way from the beginning you don't need to change;
#Override
public void onSuccess(Void aVoid) {
Toast.makeText(v.getContext(),"Email de verificação enviado.", Toast.LENGTH_SHORT).show();
}
Give a try and let's see if works!

android.widget.ProgressBar cannot be cast to android.widget.RelativeLayout

I'm new to android studio. Currently I'm working on a medlabtut app on android for over 3 months now. I'm having an issue on the login button on the MedLabStartUpScreen that actually supposed to launch the login screen when clicked on. Rather it crashes the app completely and shows a runtimeException at my //Connection Hooks "progressbar = findViewById(R.id.login_progress_bar);" of my login.java class file, that android.widget.ProgressBar cannot be cast to android.widget.RelativeLayout. I need your help please
My Login layout activity
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Common.LoginSignup.Login"
android:orientation="vertical"
android:background="#fff"
android:padding="25dp"
android:transitionName="transition_login">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/logo_name"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Welcome Back! Login Here"
android:textSize="40sp"
android:transitionName="logo_text"
android:fontFamily="#font/bungee"
android:textColor="#000"
android:layout_marginTop="20dp"/>
<TextView
android:id="#+id/slogan_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sign In to continue"
android:textSize="18sp"
android:layout_marginTop="10dp"
android:fontFamily="#font/muli_black"
android:transitionName="logo_desc"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="30dp"
android:layout_marginBottom="20dp">
<com.hbb20.CountryCodePicker
android:id="#+id/login_country_code_picker"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:ccp_autoDetectCountry="true"
app:ccp_showFlag="true"
app:ccp_showNameCode="true"
app:ccp_showFullName="true"
android:padding="5dp"
android:background="#drawable/black_border"/>
<com.google.android.material.textfield.TextInputLayout
android:layout_width="match_parent"
android:layout_below="#+id/login_country_code_picker"
android:id="#+id/login_phone_number"
android:layout_height="wrap_content"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
android:hint="#string/phone_number"
android:textColorHint="#color/Black"
app:boxStrokeColor="#color/Black"
app:boxStrokeWidthFocused="2dp"
app:endIconMode="clear_text"
app:endIconTint="#color/Black"
app:hintTextColor="#color/Black"
app:startIconDrawable="#drawable/field_phone_number_icon"
app:startIconTint="#color/Black">
<com.google.android.material.textfield.TextInputEditText
android:id="#+id/login_phone_number_editText"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:inputType="phone" />
</com.google.android.material.textfield.TextInputLayout>
<com.google.android.material.textfield.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/login_password"
android:layout_below="#+id/login_phone_number"
android:hint="#string/password"
app:startIconDrawable="#drawable/field_password_icon"
app:startIconTint="#color/Black"
android:transitionName="password_tran"
app:passwordToggleEnabled="true"
app:passwordToggleTint="#color/Black"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">
<com.google.android.material.textfield.TextInputEditText
android:id="#+id/login_password_editText"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fontFamily="#font/muli_bold"
android:inputType="textPassword" />
</com.google.android.material.textfield.TextInputLayout>
<RelativeLayout
android:id="#+id/forget_password_block"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/login_password"
android:layout_marginTop="10dp">
<CheckBox
android:id="#+id/remember_me"
style="#style/Widget.AppCompat.CompoundButton.CheckBox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:text="#string/remember_me" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/forget_password"
android:background="#00000000"
android:layout_alignParentEnd="true"
android:onClick="callForgetPassword"
android:layout_alignParentRight="true"/>
</RelativeLayout>
<Button
android:id="#+id/letTheUserLogin"
android:layout_below="#+id/forget_password_block"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:layout_marginTop="5dp"
android:background="#000"
android:text="#string/login"
android:onClick="letTheUserLoggedIn"
android:textColor="#fff"
android:transitionName="button_tran" />
<RelativeLayout
android:id="#+id/login_sign_google_box"
android:layout_width="match_parent"
android:layout_height="50dp"
android:padding="10dp"
android:layout_margin="5dp"
android:background="#drawable/rounded_rectangle"
android:layout_below="#+id/letTheUserLogin">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/signin_with_google_icon"
android:layout_centerVertical="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="SIGN IN WITH GOOGLE"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:fontFamily="#font/muli_bold"
android:layout_margin="5dp"
android:textColor="#000"/>
<Button
android:id="#+id/google_signIn"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/transparent" />
</RelativeLayout>
<Button
android:id="#+id/signup_screen"
android:layout_below="#+id/login_sign_google_box"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#00000000"
android:text="Create Account"
android:layout_centerHorizontal="true"
android:elevation="0dp"
android:layout_margin="5dp"
android:textColor="#000"
android:transitionName="login_signup_tran"/>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="20dp"
android:layout_centerInParent="true"
android:background="#drawable/white_circle"
android:elevation="10dp">
<ProgressBar
android:id="#+id/login_progress_bar"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_centerInParent="true"/>
</RelativeLayout>
<ImageView
android:id="#+id/social_fb"
android:layout_below="#+id/signup_screen"
android:layout_width="50dp"
android:layout_height="45dp"
android:src="#drawable/social_facebook_icon"
android:layout_marginLeft="130dp" />
<ImageView
android:id="#+id/social_tw"
android:layout_below="#id/signup_screen"
android:layout_width="45dp"
android:layout_height="45dp"
android:layout_centerHorizontal="true"
android:layout_marginLeft="150dp"
android:src="#drawable/social_twitter_icon" />
<ImageView
android:id="#+id/social_wh"
android:layout_width="45dp"
android:layout_height="45dp"
android:layout_below="#id/signup_screen"
android:layout_marginLeft="250dp"
android:src="#drawable/social_whatsapp_icon" />
</RelativeLayout>
</LinearLayout>
And the code for login.java class file
public class Login extends AppCompatActivity {
CountryCodePicker countryCodePicker;
Button callSignUp, login_btn;
TextView logoText, sloganText;
TextInputLayout username, phoneNumber, password;
RelativeLayout progressbar;
CheckBox rememberMe;
EditText phoneNumberEditText, passwordEditText;
private GoogleSignInClient mGoogleSignInClient;
private final static int RC_SIGN_IN = 123; // request code
Button verify;
private FirebaseAuth mAuth;
#Override
protected void onStart() {
super.onStart();
FirebaseUser user = mAuth.getCurrentUser();
if (user!=null){
Intent intent = new Intent(getApplicationContext(), MedLabDashboard.class);
startActivity(intent);
}
}
#SuppressLint("WrongViewCast")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_login);
mAuth = FirebaseAuth.getInstance();
createRequest();
//when the user clicks the google button,call the signIn method
findViewById(R.id.google_signIn).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
signIn();
}
});
//Connection Hooks
countryCodePicker = findViewById(R.id.country_code_picker);
phoneNumber = findViewById(R.id.login_phone_number);
progressbar = findViewById(R.id.login_progress_bar);
callSignUp = findViewById(R.id.signup_screen);
image = findViewById(R.id.logo_image);
logoText = findViewById(R.id.logo_name);
sloganText = findViewById(R.id.slogan_name);
password = findViewById(R.id.login_password);
login_btn = findViewById(R.id.Login_btn);
rememberMe = findViewById(R.id.remember_me);
phoneNumberEditText = findViewById(R.id.login_phone_number_editText);
passwordEditText = findViewById(R.id.login_password_editText);
//Check whether phone number and password is already saved in Shared Preference or not
SessionManager sessionManager = new SessionManager(Login.this, SessionManager.SESSION_REMEMBERME);
if (sessionManager.checkRemeberMe()){
HashMap<String,String> rememberMeDetails = sessionManager.getRememberMeDetailFromSession();
phoneNumberEditText.setText(rememberMeDetails.get(SessionManager.KEY_SESSIONPHONENUMBER));
passwordEditText.setText(rememberMeDetails.get(SessionManager.KEY_SESSIONPASSWORD));
}
callSignUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(Login.this, SignUp.class);
Pair[] pairs = new Pair[7];
pairs[0] = new Pair<View, String>(image, "logo_image");
pairs[1] = new Pair<View, String>(logoText, "logo_name");
pairs[2] = new Pair<View, String>(sloganText, "logo_desc");
pairs[3] = new Pair<View, String>(username, "username_tran");
pairs[4] = new Pair<View, String>(password, "password_tran");
pairs[5] = new Pair<View, String>(login_btn, "button_tran");
pairs[6] = new Pair<View, String>(callSignUp, "login_signup_tran");
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
try {
startActivity(intent);
} catch (Exception e) {
e.printStackTrace();
}
}
}
});
}
//Setting Auto Google Sign In request
private void createRequest() {
// Configure Google Sign In
GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestIdToken(getString(R.string.default_web_client_id))
.requestEmail()
.build();
// Build a GoogleSignInClient with the options specified by gso.
mGoogleSignInClient = GoogleSignIn.getClient(this, gso);
}
//SignIn with google method that'll pop-up user google accounts (Intent)
private void signIn() {
Intent signInIntent = mGoogleSignInClient.getSignInIntent();
startActivityForResult(signInIntent, RC_SIGN_IN);
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);
if (requestCode == RC_SIGN_IN) {
Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
try {
//Google Sign in was successful, authenticate with firebase
GoogleSignInAccount account = task.getResult(ApiException.class);
firebaseAuthWithGoogle(account);
} catch (ApiException e){
//Sign in failed, update UI appropriately
Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
}
private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
mAuth.signInWithCredential(credential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
FirebaseUser user = mAuth.getCurrentUser();
Intent intent = new Intent(getApplicationContext(), MedLabDashboard.class);
startActivity(intent);
} else {
Toast.makeText(Login.this, "Sorry authentication failed", Toast.LENGTH_SHORT).show();
}
}
});
}
//login the user in app
public void letTheUserLoggedIn(View view) {
//Check the internet connection
CheckInternet checkInternet = new CheckInternet();
if (!isConnected(Login.this)) {
showCustomDialog();
}
//validate user and password
if (!validateFields()) {
return;
}
progressbar.setVisibility(View.VISIBLE);
//get value from fields
String _phoneNumber = phoneNumber.getEditText().getText().toString().trim();
final String _password = password.getEditText().getText().toString().trim();
if (_phoneNumber.charAt(0) == '0') { //if the user uses proceeding zero (0)
_phoneNumber = _phoneNumber.substring(1);
}
final String _completePhoneNumber = "+" + countryCodePicker.getFullNumber() + _phoneNumber;
//Remember me checkbox
if (rememberMe.isChecked()){
SessionManager sessionManager = new SessionManager(Login.this,SessionManager.SESSION_REMEMBERME);
sessionManager.createRememberMeSession(_phoneNumber, _password);
}
//database query if user exist or not
Query checkUser = FirebaseDatabase.getInstance().getReference("Users").orderByChild("phoneNo").equalTo(_completePhoneNumber);
checkUser.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) { //if the data has arrived or exists
phoneNumber.setError(null); //if there's any error on the phoneNumber, remove
phoneNumber.setErrorEnabled(false); //if there is error space, set to false
String systemPassword = dataSnapshot.child(_completePhoneNumber).child("password").getValue(String.class);
//if password exist and matches with users password, then get other fields from firebase database
if (systemPassword.equals(_password)) {
password.setError(null); //if there's any error on the password, remove
password.setErrorEnabled(false); //if there is error space, set to false
String _fullname = dataSnapshot.child(_completePhoneNumber).child("fullName").getValue(String.class);
String _username = dataSnapshot.child(_completePhoneNumber).child("username").getValue(String.class);
String _email = dataSnapshot.child(_completePhoneNumber).child("email").getValue(String.class);
String _phoneNo = dataSnapshot.child(_completePhoneNumber).child("phoneNo").getValue(String.class);
String _password = dataSnapshot.child(_completePhoneNumber).child("password").getValue(String.class);
String _dateOfBirth = dataSnapshot.child(_completePhoneNumber).child("date").getValue(String.class);
String _gender = dataSnapshot.child(_completePhoneNumber).child("gender").getValue(String.class);
//Create a session
SessionManager sessionManager = new SessionManager(Login.this, SessionManager.SESSION_USERSESSION);
sessionManager.createLoginSession(_fullname, _username, _email, _phoneNo, _password, _dateOfBirth, _gender);
startActivity(new Intent(getApplicationContext(), MedLabDashboard.class));
Toast.makeText(Login.this, _fullname + "\n" + _email + "\n" + _phoneNo + "\n" + _dateOfBirth, Toast.LENGTH_SHORT).show();
progressbar.setVisibility(View.GONE);
} else {
progressbar.setVisibility(View.GONE);
Toast.makeText(Login.this, "Password does not match!", Toast.LENGTH_SHORT).show();
}
} else {
progressbar.setVisibility(View.GONE);
Toast.makeText(Login.this, "No such user exist", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
progressbar.setVisibility(View.GONE);
Toast.makeText(Login.this, databaseError.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
//check internet connection
private boolean isConnected(Login login) {
ConnectivityManager connectivityManager = (ConnectivityManager) login.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo wifiConn = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
NetworkInfo mobileConn = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if ((wifiConn != null && wifiConn.isConnected()) || (mobileConn != null && mobileConn.isConnected())) {
return true;
} else {
return false;
}
}
private void showCustomDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(Login.this);
builder.setMessage("Please connect to the internet to continue");
builder.setCancelable(false)
.setPositiveButton("Connect", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
startActivity(new Intent(getApplicationContext(), MedLabStartUpScreen.class));
finish();
}
});
}
private boolean validateFields() {
String _phoneNumber = phoneNumber.getEditText().getText().toString().trim();
String _password = password.getEditText().getText().toString().trim();
if (_phoneNumber.isEmpty()) {
phoneNumber.setError("Phone number cannot be empty");
phoneNumber.requestFocus();
return false;
} else if (_password.isEmpty()) {
password.setError("Password cannot be empty");
password.requestFocus();
return false;
} else {
password.setError(null);
password.setErrorEnabled(false);
return true;
}
}
public void callForgetPassword(View view){
startActivity(new Intent(getApplicationContext(), ForgetPassword.class));
}
#Override
public void onBackPressed() {
Intent a = new Intent(Intent.ACTION_MAIN);
a.addCategory(Intent.CATEGORY_HOME);
a.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(a);
finish();
}}
MedLabStartUpScreen Activity screen
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/White"
android:padding="30dp"
tools:context=".Common.LoginSignup.MedLabStartUpScreen">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="300dp"
android:src="#drawable/splash_screen" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="120dp"
android:fontFamily="#font/muli_black"
android:text="#string/medlab_heading"
android:textAlignment="center"
android:textAllCaps="true"
android:textColor="#color/Black"
android:textSize="36sp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:fontFamily="#font/muli_light"
android:text="#string/medlab_tab_line"
android:textAlignment="center"
android:textColor="#color/Black" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="40dp">
<Button
android:id="#+id/login_btn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:layout_marginEnd="10dp"
android:onClick="callLoginScreen"
android:layout_weight="1"
android:background="#color/colorPrimaryDark"
android:text="#string/login"
android:textColor="#color/Black"
tools:ignore="ButtonStyle"
android:transitionName="transition_login"/>
<Button
android:id="#+id/signup_btn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_weight="1"
android:background="#color/colorPrimaryDark"
android:text="#string/sign_up"
android:textColor="#color/Black" />
</LinearLayout>
<Button
android:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="wrap_content"
android:text="#string/how_we_work"
android:textColor="#color/Black"
android:layout_marginTop="20dp"
android:background="#00000000"/>
</LinearLayout>
</ScrollView>
MedLabStartUPScreen.java class that has the login button
public class MedLabStartUpScreen extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_med_lab_start_up_screen);
}
public void callLoginScreen(View view){
Intent intent = new Intent(getApplicationContext(), Login.class);
Pair[] pairs = new Pair[1];
pairs[0] = new Pair<View,String>(findViewById(R.id.login_btn), "transition_login");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
ActivityOptions options = ActivityOptions.makeSceneTransitionAnimation(MedLabStartUpScreen.this, pairs);
startActivity(intent, options.toBundle());
}
else {
startActivity(intent);
}
}
}

On around line 7 you declare this variable:
RelativeLayout progressbar;
You then correctly go on to initialise this variable with:
progressbar = findViewById(R.id.login_progress_bar);
The issue is that in the xml, the view (widget) with this ID is a ProgressBar, but the type declaration for progressbar in the Java code is RelativeLayout. Your code is therefore trying to cast the ProgressBar in the layout file into a RelativeLayout, which can't be done.
You can fix this by changing the declaration on line 7 to:
ProgressBar progressbar;
(And then adding the necessary import at the top of your Java file: import android.widget.ProgressBar;).
Hope this helped.

Start activity in another activity in Android

After press SignUp button, Display error : unfortunately app has stopped
LogCat error : java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lolacupcakes/com.example.lolacupcakes.HomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
SignUpActivity: Java Code
public class SignUpActivity extends AppCompatActivity {
EditText emailId, password;
Button btnSignUp;
TextView tvSignIn;
FirebaseAuth mFirebaseAuth;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_signup);
mFirebaseAuth = FirebaseAuth.getInstance();
emailId = findViewById(R.id.emailIDSignUp);
password = findViewById(R.id.pwdIDSignUp);
btnSignUp = findViewById(R.id.btnIDSignUp);
tvSignIn = findViewById(R.id.textView);
btnSignUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String email = emailId.getText().toString();
String pwd = password.getText().toString();
if(email.isEmpty())
{
emailId.setError("Please Enter Email Id");
emailId.requestFocus();
}
else if (pwd.isEmpty())
{
password.setError("Please Enter Email Id");
password.requestFocus();
}
else if (email.isEmpty() && pwd.isEmpty())
{
Toast.makeText(SignUpActivity.this, "Fields are Empty",Toast.LENGTH_SHORT).show();
}
else if (!(email.isEmpty() && pwd.isEmpty()))
{
mFirebaseAuth.createUserWithEmailAndPassword(email,pwd).addOnCompleteListener(SignUpActivity.this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (!task.isSuccessful())
{
Toast.makeText(SignUpActivity.this, "SignUp Unsuccessful, Please Try Again",Toast.LENGTH_SHORT).show();
}
else
{
startActivity(new Intent(SignUpActivity.this,HomeActivity.class));
}
}
});
}
else
{
Toast.makeText(SignUpActivity.this, "Error Occurred!",Toast.LENGTH_SHORT).show();
}
}
});
tvSignIn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(SignUpActivity.this, LoginActivity.class);
startActivity(i);
}
});
}
}
SignUpActivity XML:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".SignUpActivity">
<Button
android:id="#+id/btnIDSignUp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="132dp"
android:text="Sign Up" />
<ImageView
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="62dp"
android:src="#drawable/logo_lola" />
<EditText
android:id="#+id/pwdIDSignUp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="206dp"
android:ems="10"
android:hint="Password"
android:inputType="textPassword" />
<EditText
android:id="#+id/emailIDSignUp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="269dp"
android:ems="10"
android:hint="Email"
android:inputType="textEmailAddress" />
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="87dp"
android:text="Already have an account? Sign in here." />
</RelativeLayout>
HomeActivity Java Code:
public class HomeActivity extends AppCompatActivity {
Button btnlogout;
FirebaseAuth mFirebaseAuth;
private FirebaseAuth.AuthStateListener mAuthStateListener;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
btnlogout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseAuth.getInstance().signOut();
Intent intoMain = new Intent(HomeActivity.this, SignUpActivity.class);
startActivity(intoMain);
}
});
}
}
HomeActivityXML:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".HomeActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="Welcome"
android:textSize="50dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
<Button
android:id="#+id/btnLogout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Logout"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
tools:layout_editor_absoluteY="424dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

You missed initializing btnlogout. Add this line in HomeActivity onCreate before setting View.OnClickListener
btnlogout = findViewById(R.id.btnLogout);

You need to create btnSignUp object before setonlicklistener for button
btnSignUp = findViewById(R.id.btnLogout);

You need to create the btnSignUp object before setonclicklistener.

Android Studio button going in to wrong page

In my main page I have 3 different buttons.
Login (loginB)
Create a new account (createB)
Terms of conduct (termsB)
So far it has worked just fine, but for some reason I have now faced a problem with the create new account button. It did go to the right page before but now it goes to a wrong page. It should be going to the CreateAccount -page but it is going to the Menu -page.
I have the java code in the MainActivity were the buttons are here:
public class MainActivity extends AppCompatActivity {
Button loginB;
Button termsB;
Button createB;
EditText emailL,passwordL;
FirebaseAuth fAuth;
ProgressBar progressB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
createB = findViewById(R.id.createB);
createB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openCreateAccount();
}
});
termsB = findViewById(R.id.termsB);
termsB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openTermsOfConduct();
}
});
emailL = findViewById(R.id.emailL);
passwordL = findViewById(R.id.passwordL);
fAuth = FirebaseAuth.getInstance();
loginB = findViewById(R.id.loginB);
progressB = findViewById(R.id.progressB);
loginB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String email = emailL.getText().toString().trim();
String password = passwordL.getText().toString().trim();
if(TextUtils.isEmpty(email)){
emailL.setError("Email is required.");
return;
}
if(TextUtils.isEmpty(password)){
passwordL.setError("Password is required.");
return;
}
if(password.length() <6){
passwordL.setError("Password must be at least 6 characters.");
}
progressB.setVisibility(View.VISIBLE);
//authenticate the user
fAuth.signInWithEmailAndPassword(email,password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if(task.isSuccessful()){
Toast.makeText(MainActivity.this, "Logged in successfully", Toast.LENGTH_SHORT).show();
startActivity(new Intent(getApplicationContext(),Menu.class));
}
else{
Toast.makeText(MainActivity.this, "Error " + task.getException().getMessage(), Toast.LENGTH_SHORT).show();
progressB.setVisibility(View.INVISIBLE);
}
}
});
}
});
}
public void openCreateAccount(){
Intent intent = new Intent(this, CreateAccount.class);
startActivity(intent);
}
public void openTermsOfConduct(){
Intent intent = new Intent(this, TermsOfConduct.class);
startActivity(intent);
}
}
Main Activity xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"
android:background="#drawable/tausta">
<TextView
android:layout_width="match_parent"
android:layout_height="180dp"
android:fontFamily="sans-serif"
android:paddingVertical="30dp"
android:text="Login"
android:textAlignment="center"
android:textColor="#000"
android:textSize="90sp"
android:layout_marginBottom="25dp"
/>
<EditText
android:id="#+id/emailL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="30dp"
android:layout_marginBottom="30dp"
android:textColor="#fff"
android:textSize="25sp"
android:hint="Email"
android:textColorHint="#fff"
/>
<EditText
android:id="#+id/passwordL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="30dp"
android:inputType="textPassword"
android:layout_marginBottom="30dp"
android:textColor="#fff"
android:textSize="25sp"
android:hint="Password"
android:textColorHint="#fff"
/>
<Button
android:id="#+id/loginB"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Login"
android:layout_marginHorizontal="30dp"
android:layout_marginBottom="25dp"
android:background="#drawable/button_bg"
/>
<Button
android:id="#+id/createB"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Create a new account"
android:layout_marginHorizontal="30dp"
android:layout_marginBottom="25dp"
android:background="#drawable/button_bg"
/>
<Button
android:id="#+id/termsB"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Terms and conditions"
android:layout_marginHorizontal="30dp"
android:textColor="#0070ff"
android:textAlignment="center"
android:background="#android:color/transparent"
/>
<ProgressBar
android:id="#+id/progressB"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="invisible"
/>
</LinearLayout>
CreateAccount java:
public class CreateAccount extends AppCompatActivity {
Button registerB;
EditText nameR,emailR,pnumberR,passwordR;
FirebaseAuth fAuth;
ProgressBar progressB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_account2);
nameR = findViewById(R.id.nameR);
emailR = findViewById(R.id.emailR);
pnumberR = findViewById(R.id.pnumberR);
passwordR = findViewById(R.id.passwordR);
progressB = findViewById(R.id.progressB);
fAuth = FirebaseAuth.getInstance();
//check if user registered
if(fAuth.getCurrentUser() != null){
startActivity(new Intent(getApplicationContext(),Menu.class));
finish();
}
registerB = findViewById(R.id.registerB);
registerB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String email = emailR.getText().toString().trim();
String password = passwordR.getText().toString().trim();
if(TextUtils.isEmpty(email)){
emailR.setError("Email is required.");
return;
}
if(TextUtils.isEmpty(password)){
passwordR.setError("Password is required.");
return;
}
if(password.length() <6){
passwordR.setError("Password must be ata least 6 characters.");
return;
}
progressB.setVisibility(View.VISIBLE);
//register the user to FireBase
fAuth.createUserWithEmailAndPassword(email,password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if(task.isSuccessful()){
Toast.makeText(CreateAccount.this, "User created.", Toast.LENGTH_SHORT).show();
startActivity(new Intent(getApplicationContext(),Menu.class));
}
else{
Toast.makeText(CreateAccount.this, "Error " +task.getException().getMessage(), Toast.LENGTH_SHORT).show();
}
}
});
}
});
}
}
CreateAccount xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".CreateAccount"
android:background="#drawable/tausta"
>
<TextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:fontFamily="sans-serif"
android:paddingVertical="20dp"
android:text="Create new account"
android:textAlignment="center"
android:textColor="#000"
android:textSize="40sp"
android:layout_marginBottom="25dp"
/>
<EditText
android:id="#+id/nameR"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Full name"
android:textColorHint="#fff"
android:textSize="25sp"
android:layout_marginHorizontal="25dp"
android:layout_marginBottom="30dp"
/>
<EditText
android:id="#+id/emailR"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Email"
android:textColorHint="#fff"
android:textSize="25sp"
android:layout_marginHorizontal="25dp"
android:layout_marginBottom="30dp"
/>
<EditText
android:id="#+id/pnumberR"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Phone number"
android:textColorHint="#fff"
android:textSize="25sp"
android:layout_marginHorizontal="25dp"
android:layout_marginBottom="30dp"
/>
<EditText
android:id="#+id/passwordR"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Password"
android:textColorHint="#fff"
android:textSize="25sp"
android:layout_marginHorizontal="25dp"
android:layout_marginBottom="30dp"
/>
<Button
android:id="#+id/registerB"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Register"
android:layout_marginHorizontal="30dp"
android:layout_marginBottom="25dp"
android:background="#drawable/button_bg"
/>
<ProgressBar
android:id="#+id/progressB"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="invisible"
/>
</LinearLayout>

I guess you should definitely check(R.layout.activity_create_account2)and whether it is the correct xml for the CreateAccount.java
P.S. While posting questions, always mention the correct name of the xml too.

The following code might be the cause:
if(fAuth.getCurrentUser() != null){
startActivity(new Intent(getApplicationContext(),Menu.class));
finish();
}
Can you check if it's going into the if block?

My app is crashing when starting an activity with intent yet no error is shown in the logcat

Here's the main activity
public class MainActivity extends Activity {
///Lot of code here which does work
Cursor pscod = db.rawQuery("SELECT * FROM myTable", null);
Cursor phoneCode=db.rawQuery("SELECT * FROM myPhone", null);
if(!(pscod.getCount()==0)&&!(phoneCode.getCount()==0))
{
Toast.makeText(getApplicationContext(),"hai",Toast.LENGTH_LONG).show();
Intent dialogboxintent = new Intent(getApplicationContext(),FAQ.class);
startActivity(dialogboxintent);
}
I know that the compiler does check the if condition and gets inside since the toast does occur. The activity is defined in the manifest file as
<activity android:name="com.example.profilechanger.FAQ"></activity>
The new activity just crashes without showing the layout I have set it to view.
Here's the FAQ class
public class FAQ extends AppCompatActivity {
ImageButton keyimage;
SQLiteDatabase db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.faq);
db = openOrCreateDatabase("myDataBase.db", Context.MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS myTable(passcode VARCHAR);");
db.execSQL("CREATE TABLE IF NOT EXISTS masterPass(masterName VARCHAR,masterPassword VARCHAR);");
db.execSQL("CREATE TABLE IF NOT EXISTS myPhone(lockPassword VARCHAR);");
keyimage = (ImageButton) findViewById(R.id.keybutton);
keyimage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Cursor pscod = db.rawQuery("SELECT * FROM myTable", null);
Cursor phoneCode=db.rawQuery("SELECT * FROM myPhone", null);
if (pscod.getCount()==0&&phoneCode.getCount()==0)
{
Toast.makeText(FAQ.this, "SET PASSCODE AND LOCKCODE", Toast.LENGTH_SHORT).show();
}
else
{
final Dialog masterDialog = new Dialog(FAQ.this);
masterDialog.setContentView(R.layout.mastercode_enter_layout);
masterDialog.setCancelable(false);
masterDialog.setTitle("ENTER MASTER PASSWORD");
final EditText master_edt_pass = (EditText) masterDialog.findViewById(R.id.master_editTextPasswordToLogin);
Button master_btn_submit = (Button) masterDialog.findViewById(R.id.master_buttonSignIn);
master_btn_submit.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
// get The User name and Password
String masterPASSWORD = master_edt_pass.getText().toString();
// check if the Stored password matches with Password entered by user
if (masterPASSWORD.trim().length()==0) {
showMessage("Error", "Please enter PASSWORD");
return;
}
Cursor c = db.rawQuery("SELECT * FROM masterPass WHERE masterPassword ='" + masterPASSWORD + "'", null);
if (c.moveToFirst()) {
showMessage("Success","LOGIN SUCCESS");
Intent profileIntent = new Intent(getApplicationContext(),Profile.class);
startActivity(profileIntent);
masterDialog.dismiss();
} else {
showMessage("Error", "Invalid attempt");
finish();
}
}
});
masterDialog.show();
}
}
});
}
public void showprofilemode(View view) {
android.support.v4.app.FragmentManager manager=getSupportFragmentManager();
MyDialog myDialog=new MyDialog();
myDialog.show(manager,"Profile");
}
public void callbackbutton(View view) {
android.support.v4.app.FragmentManager manager2=getSupportFragmentManager();
Callbackdialog calldialog=new Callbackdialog();
calldialog.show(manager2,"Call Back");
}
public void locknowbutton(View view) {
android.support.v4.app.FragmentManager manager3=getSupportFragmentManager();
Locknowdialog locknowdialog=new Locknowdialog();
locknowdialog.show(manager3,"Lock Now");
}
public void alerttonebutton(View view) {
android.support.v4.app.FragmentManager manager4=getSupportFragmentManager();
Alerttone alertnow=new Alerttone();
alertnow.show(manager4,"Play Alert");
}
public void locationbutton(View view) {
android.support.v4.app.FragmentManager manager5=getSupportFragmentManager();
Location1 location=new Location1();
location.show(manager5,"Get Location");
}
public void simchangebutton(View view) {
android.support.v4.app.FragmentManager manager6=getSupportFragmentManager();
Simchangedialog simchange=new Simchangedialog();
simchange.show(manager6,"Sim Change");
}
public void showMessage(String title, String message) {
AlertDialog.Builder builder;
builder = new AlertDialog.Builder(this);
builder.setCancelable(true);
builder.setTitle(title);
builder.setMessage(message);
builder.show();
}
}
The activity doesn't even show the view FAQ layout
Here's faq.xml file
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/faq"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.profilechanger.FAQ">
<Button
android:id="#+id/angry_btn"
android:text="Changing the ring mode of the device"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="showprofilemode"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/>
<Button
android:id="#+id/callbackbutton"
android:layout_below="#+id/angry_btn"
android:text="Getting a call back from the lost phone"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="callbackbutton"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/>
<Button
android:id="#+id/locknowbutton"
android:layout_below="#+id/callbackbutton"
android:text="To Lock the phone"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="locknowbutton"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/>
<Button
android:id="#+id/alertonebutton"
android:layout_below="#+id/locknowbutton"
android:text="To play alert tone"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="alerttonebutton"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/>
<Button
android:id="#+id/locationbutton"
android:layout_below="#+id/alertonebutton"
android:text="To Track the Phone's location"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="locationbutton"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/>
<Button
android:id="#+id/simchangebutton"
android:layout_below="#+id/locationbutton"
android:text="What happens when your sim is changed?"
android:textColor="#2E3CFF"
android:textSize="15sp"
android:textAllCaps="false"
android:onClick="simchangebutton"
android:layout_width="1000dp"
android:layout_height="60dp"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A7A6"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="5"
/><LinearLayout
android:layout_below="#id/locationbutton"
android:layout_marginTop="55dp"
android:gravity="center_horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<ImageButton
android:background="#drawable/change_passcode"
android:layout_width="80dp"
android:layout_height="80dp"
android:id="#+id/keybutton"
android:layout_gravity="center_horizontal" />
</LinearLayout>
</RelativeLayout>
Logcat doesn't even show anything. Please help.