Android Click Event Error

Android Click Event Error - java

I get this strange error, when I activate my clickListener
Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)'
on a null object reference
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (Build.VERSION.SDK_INT < 16) {
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
}
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
setContentView(R.layout.activity_main);
WebView webView = (WebView) findViewById(R.id.webView);
webView.loadData("test ", "text/html", "utf-8");
webView.loadUrl("https://www.google.de/");
webView.getSettings().setDomStorageEnabled(true);
PrefUtils.setKioskModeActive(true, getApplicationContext());
}
#Override
public void onBackPressed() {
Context context = getApplicationContext();
CharSequence text = "password to deactivate mode!";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
myDialog = new Dialog(this);
myDialog.setContentView(R.layout.dialog_signin);
myDialog.setCancelable(false);
password = (EditText) myDialog.findViewById(R.id.password);
myDialog.show();
// Error probably because of this
Button lbtn = (Button)findViewById(R.id.loginButton);
lbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (password.getText().toString().equals("123")) {
Log.d("myapp", "test1");
} else {
Log.d("myapp", "test2");
}
}
});
}
so basically a dialog textfield windows appears, when I click on the back button. Inside this I check if the password of 123 is correct or not.
Here is my dialog_signin.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<EditText
android:id="#+id/password"
android:inputType="textPassword"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:layout_marginLeft="4dp"
android:layout_marginRight="4dp"
android:layout_marginBottom="16dp"
android:fontFamily="sans-serif" />
<!--android:hint="#string/password"-->
<Button
android:id="#+id/loginButton"
android:layout_width="200dp"
android:layout_height="30dp"
android:background="#color/red"/>
</LinearLayout>
and this is my activity_main.xml:
<RelativeLayout 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:keepScreenOn="true"
tools:context=".MainActivity">
<WebView
android:id="#+id/webView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true">
</WebView>
</RelativeLayout>

You are attempting for find the Button in your Activity or Fragment layout, not in the Dialog:
Button lbtn = (Button)findViewById(R.id.loginButton);
should be
Button lbtn = (Button)myDialog.findViewById(R.id.loginButton);

You need to get the Button from the view it is in. If you use findViewById without any view reference then it would try to find the view in you activity xml in this case activity_main.xml. loginButton is not in this xml but in the dialog you have created that's why you are getting NPE. So, change
Button lbtn = (Button)findViewById(R.id.loginButton);
to
Button lbtn = (Button)myDialog.findViewById(R.id.loginButton);

Replace your code with this :
#Override
public void onBackPressed() {
Context context = getApplicationContext();
CharSequence text = "password to deactivate mode!";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
myDialog = new Dialog(this);
myDialog.setContentView(R.layout.dialog_signin);
myDialog.setCancelable(false);
password = (EditText) myDialog.findViewById(R.id.password);
myDialog.show();
// Error probably because of this
Button lbtn = (Button)myDialog.findViewById(R.id.loginButton);
lbtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (password.getText().toString().equals("123")) {
Log.d("myapp", "test1");
} else {
Log.d("myapp", "test2");
}
}
});

Related

is there a way to interact with a custom layout inflated in an Alert Dialog?

I have a code which inflates a custom layout inside an Alert Dialog.
The Custom Layout consists of an EditText and a Button. What is the correct way to display the EditText String inside a Toast by clicking the Button ?
I have tried the below code but it doesn't seem to work.
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setPositiveButton("Fetch", (dialog, which) -> {
}).setNeutralButton("Cancel", (dialog, which) -> {
});
final AlertDialog dialog = builder.create();
LayoutInflater inflater = getLayoutInflater();
View dialogLayout = inflater.inflate(R.layout.custom_layout, null);
dialog.setView(dialogLayout);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.show();
dialog.setOnShowListener(d -> {
EditText dialogNameEditText = dialog.findViewById(R.id.dialog_name_edittext);
Button dialogPrintButton = dialog.findViewById(R.id.dialog_print_button);
dialogPrintButton.setOnClickListener(v1 -> {
Toast.makeText(
TestActivity.this,
dialogNameEditText.getText().toString(),
Toast.LENGTH_SHORT
).show();
});
});
custom_layout.xml file
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="12dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<EditText
android:id="#+id/dialog_name_edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorDark"
android:ems="10"
android:hint="Name"
android:inputType="text"
android:padding="10dp"
android:textColor="#color/colorWhite"
android:textColorHint="#color/colorLight" />
<Button
android:id="#+id/dialog_print_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:backgroundTint="#color/colorPrimary"
android:text="Print"
android:textColor="#color/colorLight" />
</LinearLayout>

Originally answered
Create a separate function for toast
public void show_toast(){
Toast.makeText(
TestActivity.this,
dialogNameEditText.getText().toString(),
Toast.LENGTH_SHORT
).show();
}
and in onclicklistener call it
dialog.setOnShowListener(d -> {
EditText dialogNameEditText = dialog.findViewById(R.id.dialog_name_edittext);
Button dialogPrintButton = dialog.findViewById(R.id.dialog_print_button);
dialogPrintButton.setOnClickListener(v1 -> {
show_toast();
});
});

Try this simple code. it will work.
Dialog dialog = new Dialog(this);
dialog.setContentView(R.layout.custom_layout);
EditText dialogNameEditText = dialog.findViewById(R.id.dialog_name_edittext);
Button dialogPrintButton = dialog.findViewById(R.id.dialog_print_button);
dialogPrintButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(MainActivity.this,dialogNameEditText.getText(), Toast.LENGTH_SHORT).show();
}
});
dialog.show();

Exception When handling Custom AlertDialog with ButterKnife

Hello guys iam realy Confused i spent over 17 hours try to fix this Problem but
No hope
Am try to show Custom Dialog with > AlertDialog.Builder when i Click Button but when i run the App and click the button it gives me this Exception
i tried ButterKnife #OnClick Anotation and Casting the Item Inside the Dialog Function like Button item = findviewById(R.id.ItemID);
i search for questions has same problem like mine but useless till i found
this question Multiple injections but i found that its really very old May 29, 2014
The Exception
05-23 21:15:56.630 8769-8769/com.w4ma.soft.tamenly E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.w4ma.soft.tamenly, PID: 8769
java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
at com.w4ma.soft.tamenly.View.CreateandShow.ShowThePost.ShowCommentDialog(ShowThePost.java:133)
at com.w4ma.soft.tamenly.View.CreateandShow.ShowThePost.onClick(ShowThePost.java:159)
at com.w4ma.soft.tamenly.View.CreateandShow.ShowThePost_ViewBinding$1.doClick(ShowThePost_ViewBinding.java:52)
at butterknife.internal.DebouncingOnClickListener.onClick(DebouncingOnClickListener.java:22)
at android.view.View.performClick(View.java:5647)
at android.view.View$PerformClick.run(View.java:22462)
at android.os.Handler.handleCallback(Handler.java:754)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:163)
at android.app.ActivityThread.main(ActivityThread.java:6221)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
Here is my code
ShowThePost.java
#Nullable #BindView(R.id.priceSuggested) EditText txtSuggestprice;
#Nullable #BindView(R.id.txtnotes) EditText txtNotes;
#Nullable #BindView(R.id.btnClose) Button btnclose;
#Nullable #BindView(R.id.btnCommentDone) Button btndone;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_the_post);
ButterKnife.bind(this);
}
public void ShowCommentDialog() {
final AlertDialog.Builder alert = new AlertDialog.Builder(context);
view = getLayoutInflater().inflate(R.layout.create_comment,null);
alert.setCancelable(false);
alert.setView(view);
final AlertDialog dialog = alert.create();
// final Dialog dialog = new Dialog(context);
// dialog.setContentView(R.layout.create_comment);
// dialog.setCancelable(false);
// dialog.setTitle("This is Dialog");
// EditText txtSuggestprice = findViewById(R.id.priceSuggested);
// EditText txtNotes = findViewById(R.id.txtnotes);
// Button btnDonee = (Button)findViewById( R.id.btnCommentDone);
// Button btnClosee =(Button)findViewById(R.id.btnClose);
//
// btndone.setOnClickListener(new View.OnClickListener() {
// #Override
// public void onClick(View v) {
//
//
// }
// });
// btnclose.setOnClickListener(new View.OnClickListener() {
// #Override
// public void onClick(View v) {
// dialog.dismiss();
//
// }
// });
final String Notes = txtNotes.getText().toString();
final String Description = txtSuggestprice.getText().toString();
alert.setPositiveButton("Done", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Toasty.success(context,"Done" + Notes + Description, Toast.LENGTH_LONG).show();
}
}).setNegativeButton("Close", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
btndone.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Done", Toast.LENGTH_SHORT).show();
}
});
btnclose.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Closed", Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
});
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
dialog.show();
}
#OnClick(R.id.fabComment)
public void ShowDialog(){
ShowCommentDialog();
}
CreatComment.xml this is the Custom Dialog which should Inflate to the Dialog
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:cardCornerRadius="#dimen/_12sdp">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Comment"
android:textSize="#dimen/_22sdp"
android:textColor="#000"
android:textAlignment="center"
android:layout_margin="#dimen/_9sdp"
android:typeface="serif"/>
<View
android:layout_width="match_parent"
android:layout_height="#dimen/_1sdp"
android:background="#color/lightgray"
android:padding="#dimen/_4sdp"/>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="#dimen/_4sdp">
<EditText
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/priceSuggested"
android:layout_margin="#dimen/_5sdp"
android:hint="Suggest Price"
android:inputType="number"
android:typeface="serif"/>
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="#dimen/_4sdp">
<EditText
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="#dimen/_5sdp"
android:hint="Notes"
android:id="#+id/txtnotes"
android:typeface="serif"/>
</android.support.design.widget.TextInputLayout>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Done"
android:background="#drawable/btncommentstyle"
android:id="#+id/btnCommentDone"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Close"
android:layout_marginTop="#dimen/_4sdp"
android:background="#drawable/btncommentstyle"
android:id="#+id/btnClose"/>
</LinearLayout>
</android.support.v7.widget.CardView>

The exception is caused by this line:
final String Notes = txtNotes.getText().toString();
As described in the reason, the txtNotes member is null, which means that the binding did not work (probably the view with txtnotes id was not found).
From what I see, you call ButternKnife.bind() for the activity which has the activity_show_the_post layout as content view. But the view with txtnotes id is actually in the create_comment layout, of which ButterKnife knows nothing about, and doesn't even exist at that time. Thus, the binding fails, no reference to txtnotes is created and you later get a NPE.

You need to bind the views for create_comment.xml too
view = getLayoutInflater().inflate(R.layout.create_comment,null);
Butterknife.bind(view,this);
alert.setCancelable(false);
alert.setView(view);
final AlertDialog dialog = alert.create();

Adding Items to ListView from Android AlertDialog

I have a ListView and a button i want when I press the button it takes me to a Dialogue it has a Text Field and another Button when I fill the text and press the button it will be saved in the list view ( I know how to add items from the same activity to the ListView) but I don't how to add items from another activity or AlterDialoge .
public class Main3Activity extends AppCompatActivity {
EditText et;
ListView lv;
Button bt;
ArrayList<String> arrayList;
ArrayAdapter<String> adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main3);
et = (EditText) findViewById(R.id.TextAdd);
bt = (Button) findViewById(R.id.btnadd);
lv = (ListView) findViewById(R.id.listView);
arrayList = new ArrayList<String>();
adapter= new ArrayAdapter<String>(Main3Activity.this,android.R.layout.simple_list_item_1,arrayList);
lv.setAdapter(adapter);
Button mShowDialog = (Button) findViewById(R.id.btnSave);
mShowDialog.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder mBuilder = new AlertDialog.Builder(Main3Activity.this);
View mView = getLayoutInflater().inflate(R.layout.dialog_add,null);
final EditText mUser = (EditText) mView.findViewById(R.id.TextAdd);
Button mAdd = (Button) mView.findViewById(R.id.btnadd);
mAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(!mUser.getText().toString().isEmpty()) {
String result = et.getText().toString();
arrayList.add(result);
adapter.notifyDataSetChanged();
Toast.makeText(Main3Activity.this, "Success", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(Main3Activity.this, "Error pls Write", Toast.LENGTH_SHORT).show();
}
}
});
mBuilder.setView(mView);
AlertDialog dialog = mBuilder.create();
dialog.show();
}
});
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<TextView
android:id="#+id/Add"
android:layout_gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:layout_margin="5dp"
android:textSize="25sp"
android:text="POP UP Window" />
<EditText
android:id="#+id/TextAdd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:layout_marginTop="10dp"
android:inputType="textPersonName"
android:hint="write"/>
<Button
android:id="#+id/btnadd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorAccent"
android:textColor="#android:color/white"
android:text="Add" />
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="com.example.jim_a.testapp.Main3Activity"
tools:layout_editor_absoluteY="81dp"
tools:layout_editor_absoluteX="0dp">
<Button
android:id="#+id/btnSave"
android:layout_height="73dp"
android:text="Open Window"
android:layout_width="0dp"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="16dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
tools:layout_constraintRight_creator="1"
tools:layout_constraintLeft_creator="1" />
<ListView
android:id="#+id/listView"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="13dp"
tools:layout_constraintTop_creator="1"
tools:layout_constraintRight_creator="1"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginEnd="13dp"
app:layout_constraintRight_toRightOf="parent"
android:layout_marginTop="33dp"
app:layout_constraintTop_toBottomOf="#+id/btnSave"
tools:layout_constraintLeft_creator="1"
android:layout_marginBottom="31dp"
app:layout_constraintLeft_toLeftOf="parent"
android:layout_marginLeft="13dp"
android:layout_marginRight="13dp"></ListView>
</android.support.constraint.ConstraintLayout>

Okay so I made 2 minor modifications to get your code working -
Replace "et" with "mUser" to avoid Null Pointer Exception when calling getText()
Dismiss Dialog upon successful updation of list.
Below is the onClick() method body :
AlertDialog.Builder mBuilder = new AlertDialog.Builder(Main3Activity.this);
View mView = getLayoutInflater().inflate(R.layout.dialog_add, null);
final EditText editText_mUser = (EditText) mView.findViewById(R.id.TextAdd);
Button mAdd = (Button) mView.findViewById(R.id.btnadd);
mBuilder.setView(mView);
//create dialog instance here, so that it can be dismissed from within the OnClickListener callback
final AlertDialog dialog = mBuilder.create();
mAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!editText_mUser.getText().toString().isEmpty()) {
// Instead of et.getText(), call mUser.getText()
String result = editText_mUser.getText().toString();
arrayList.add(result);
adapter.notifyDataSetChanged();
Toast.makeText(Main3Activity.this, "Success", Toast.LENGTH_SHORT).show();
//dismiss dialog once item is added successfully
dialog.dismiss();
} else {
Toast.makeText(Main3Activity.this, "Error pls Write", Toast.LENGTH_SHORT).show();
}
}
});
dialog.show();
See this for more info.
For other cases, where you want communication between 2 Activities/Fragments for Event-Based List Updation, you can check out EventBus.

Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

All I want to do is start a new intent on click of a button. Here is my code(I have removed irrelevant parts):
activity_login.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:gravity="center_horizontal"
tools:context="com.example.android.altro.LoginActivity">
<!-- Login progress -->
<ProgressBar
android:id="#+id/login_progress"
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:visibility="gone" />
<ScrollView
android:id="#+id/login_form"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/email_login_form"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<AutoCompleteTextView
android:id="#+id/email"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="#string/prompt_email"
android:inputType="textEmailAddress"
android:maxLines="1"
android:textColor="#color/colorWhite"
android:singleLine="true" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="#+id/password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="#string/prompt_password"
android:imeActionId="#+id/login"
android:imeActionLabel="#string/action_sign_in_short"
android:imeOptions="actionUnspecified"
android:inputType="textPassword"
android:maxLines="1"
android:singleLine="true" />
</android.support.design.widget.TextInputLayout>
<Button
android:id="#+id/email_sign_up_button"
style="?android:textAppearanceMedium"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/rounded_button"
android:onClick="registerNewUser"
android:text="#string/action_sign_up"
android:textAllCaps="false" />
</LinearLayout>
</ScrollView>
</LinearLayout>
On clicking #+id/email_sign_up_button registerNewUser is called. I have defined this fuction in LoginActivity.java:
public class LoginActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {
/**
* Id to identity READ_CONTACTS permission request.
*/
private static final int REQUEST_READ_CONTACTS = 0;
/**
* A dummy authentication store containing known user names and passwords.
* TODO: remove after connecting to a real authentication system.
*/
private static final String[] DUMMY_CREDENTIALS = new String[]{
"foo#example.com:hello", "bar#example.com:world"
};
/**
* Keep track of the login task to ensure we can cancel it if requested.
*/
private UserLoginTask mAuthTask = null;
// UI references.
private AutoCompleteTextView mEmailView;
private EditText mPasswordView;
private View mProgressView;
private View mLoginFormView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
// Set up the login form.
mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
populateAutoComplete();
mPasswordView = (EditText) findViewById(R.id.password);
mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
if (id == R.id.login || id == EditorInfo.IME_NULL) {
attemptLogin();
return true;
}
return false;
}
});
Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
mEmailSignInButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
attemptLogin();
}
});
mLoginFormView = findViewById(R.id.login_form);
mProgressView = findViewById(R.id.login_progress);
/* Button mRegisterButton = (Button) findViewById(R.id.email_sign_up_button);
mRegisterButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(view.getContext(), RegisterActivity.class);
startActivity(intent);
}
});*/
}
public void registerNewUser(View view) {
Intent intent = new Intent(this, RegisterActivity.class);
startActivity(intent);
}
}
I also tried doing it by finding view and then creating an intent (the code is commented out in onCreate() method. That also gave me the same error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.altro/com.example.android.altro.RegisterActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

You have only one Button with id email_sign_up_button
Please check your layout. Also try replacing
Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
With
Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_up_button);

set Inflate layout to smaller

i have some problems with my layout, this is the capture of my layout inflater
the layout is to big and the button are in wrong place, i don't use a title but there is a black title background in there
i just want to make it smaller like piano tiles layout
can anyone help me to fix this?
this is my layout.xml data that will show inflater layout in menu.java
<?xml version='1.0' encoding='utf-8'?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center"
android:background="#drawable/backgroundblankwhite"
android:gravity="center|center_horizontal|center_vertical"
android:orientation="vertical"
android:padding="10sp" >
<TextView
android:id="#+id/exitimage"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#drawable/textinflateexit"
android:singleLine="true" >
<requestFocus />
</TextView>
<LinearLayout
android:id="#+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center" >
<Button
android:id="#+id/buttonexityes"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:background="#drawable/buttonquityes" />
<Button
android:id="#+id/buttonexitno"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:background="#drawable/buttonquitno" />
</LinearLayout>
</LinearLayout>
and this is my menu.java that have a button to display my inflate layout
public class menu extends Activity {
private Context context = this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.menu);
Button exit = (Button) findViewById(R.id.exit);
exit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
final Dialog openDialog = new Dialog(context);
openDialog.setContentView(R.layout.inflatequitapp);
TextView dialogTextContent = (TextView)openDialog.findViewById(R.id.exitimage);
Button dialogExitButton = (Button)openDialog.findViewById(R.id.buttonexityes);
dialogExitButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
// if this button is clicked, close
// current activity
menu.this.finish();
}
});
Button dialogCloseButton = (Button)openDialog.findViewById(R.id.buttonexitno);
dialogCloseButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
openDialog.dismiss();
}
});
openDialog.show();
}
});
}
#Override
public void onBackPressed() {
// do nothing.
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
}

I have change a bit variable to check at my end..please do change variables,class to match at your end...
MainActivity.java
///---////
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
Button exit = (Button) findViewById(R.id.but);
exit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
final Dialog openDialog = new Dialog(MainActivity.this);
openDialog.setContentView(R.layout.main);
openDialog.setTitle("Confirm Exit");
TextView dialogTextContent = (TextView)openDialog.findViewById(R.id.exitimage);
Button dialogExitButton = (Button)openDialog.findViewById(R.id.buttonexityes);
dialogExitButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
finish();
}
});
Button dialogCloseButton = (Button)openDialog.findViewById(R.id.buttonexitno);
dialogCloseButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
openDialog.dismiss();
}
});
openDialog.show();
}
});
}
Dialog xml file..
<?xml version='1.0' encoding='utf-8'?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center"
android:background="#ffffff"
android:gravity="center|center_horizontal|center_vertical"
android:orientation="vertical"
android:padding="10sp" >
<TextView
android:id="#+id/exitimage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#ffffff"
android:singleLine="true"
android:text="Are You Sure!!" >
<requestFocus />
</TextView>
<LinearLayout
android:id="#+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center" >
<Button
android:id="#+id/buttonexityes"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:background="#ffffff"
android:text="Yes" />
<Button
android:id="#+id/buttonexitno"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:background="#ffffff"
android:text="No" />
</LinearLayout>
</LinearLayout>
output:

you have to used below code for dialog
private void forgotPasswordDialog() {
LayoutInflater layoutInflater = LayoutInflater.from(this);
final View dialogView = layoutInflater.inflate(R.layout.dialog_forgot_password, null);
AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.PauseDialog);
final AlertDialog dialog = builder.create();
dialog.setView(dialogView);
dialog.show();
final EditText edtUserNameDialog = (EditText) dialogView.findViewById(R.id.edtUserNameDialog);
edtUserNameDialog.setText(edtUserName.getText());
final Button btnSubmit = (Button) dialogView.findViewById(R.id.btnSubmit);
btnSubmit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!FieldsValidator.validateUsername(edtUserNameDialog)) {
//forgotPasswordDialog();
} else if (!checkDMSID()) {
KeyboardUtils.hideKeyboard(edtUserNameDialog);
dialog.dismiss();
} else {
KeyboardUtils.hideKeyboard(edtUserNameDialog);
forgotPassword(edtUserNameDialog.getText().toString());
dialog.dismiss();
}
}
});
final Button btnCancel = (Button) dialogView.findViewById(R.id.btnCancel);
btnCancel.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
KeyboardUtils.hideKeyboard(edtUserNameDialog);
dialog.dismiss();
}
});
}

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set Inflate layout to smaller

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