I am building a very simple currency converter app for a course I am doing.
The App has a decimal Edit text box where you enter the amount and when you press the button it will convert the amount from £ sterling to U.S dollars and gives the user the difference in a Toast message.
I need help with the java code for the currency conversion part , if anyone can help that will be much appreciated.
xml
<?xml version="1.0" encoding="utf-8"?>
<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: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.hydraquip_10.myapplication.MainActivity">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:src="#drawable/currency"
android:scaleType="center" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="numberDecimal"
android:ems="10"
android:id="#+id/editText"
android:layout_marginTop="134dp"
android:layout_below="#+id/imageView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Get Result"
android:id="#+id/button"
android:layout_marginTop="35dp"
android:onClick="changeCurrency"
android:layout_below="#+id/editText"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Enter amount £"
android:id="#+id/textView"
android:layout_alignBottom="#+id/editText"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="56dp"
android:gravity="center" />
</RelativeLayout>
main java
package com.example.hydraquip_10.myapplication;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void changeCurrency(View view){
EditText changeNumber = (EditText) findViewById(R.id.editText);
Toast.makeText(getApplicationContext(), "Currency = $" + changeNumber.getText().toString(),Toast.LENGTH_LONG).show();
}
}
Related
When I'm trying to transfer data between activities, I can't get my message and the app keeps crashing,
It show me 'app keeps stopping'
Code in MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
Intent outIntent;
EditText edtPhone;
EditText edtMessage;
Button btnNext;
String tempText="";
public static final String PHONE = "PHONE";
public static final String MESSAGE = "MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnNext = (Button) findViewById(R.id.btnNext);
btnNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View V) {
outIntent = new Intent(MainActivity.this, ActivityTwo.class);
edtPhone = (EditText) findViewById(R.id.edtPhone);
edtMessage = (EditText) findViewById(R.id.edtMessage);
tempText = edtPhone.getText().toString();
outIntent.putExtra(PHONE,tempText);
tempText = edtMessage.getText().toString();
outIntent.putExtra(MESSAGE,tempText);
startActivity(outIntent);
}
});
}
public void closeMethod(View view) {
finish();
}
}
ActivityTwo.java
package com.example.fir;
import android.content.Intent;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;
public class ActivityTwo extends AppCompatActivity {
Intent incomingIntent;
TextView txtPhone;
TextView txtMessage;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_two);
incomingIntent = getIntent();
txtPhone = (TextView) findViewById(R.id.txtPhone);
txtMessage = (TextView) findViewById(R.id.txtMessage);
txtPhone.setText(incomingIntent.getStringExtra(MainActivity.PHONE));
txtMessage.setText(incomingIntent.getStringExtra(MainActivity.MESSAGE));
}
}
Activitymain.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=".MainActivity" >
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="32dp"
android:text="Phone" />
<EditText
android:id="#+id/editTextPhone"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="0dp"
android:layout_marginTop="60dp"
android:ems="10"
android:hint="Phone"
android:inputType="phone"
android:minHeight="48dp" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="124dp"
android:text="Message" />
<EditText
android:id="#+id/editTextTextPersonName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_centerHorizontal="true"
android:layout_marginStart="0dp"
android:layout_marginTop="156dp"
android:layout_marginEnd="3dp"
android:ems="10"
android:hint="Message"
android:inputType=""
android:minHeight="48dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="224dp"
android:orientation="horizontal">
<Button
android:id="#+id/btnNext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Next" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="closeMethod"
android:text="CLose" />
</LinearLayout>
</RelativeLayout>
Activitytwo.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=".MainActivity" >
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="32dp"
android:text="Phone" />
<EditText
android:id="#+id/editTextPhone"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="0dp"
android:layout_marginTop="60dp"
android:ems="10"
android:hint="Phone"
android:inputType="phone"
android:minHeight="48dp" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="124dp"
android:text="Message" />
<EditText
android:id="#+id/editTextTextPersonName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_centerHorizontal="true"
android:layout_marginStart="0dp"
android:layout_marginTop="156dp"
android:layout_marginEnd="3dp"
android:ems="10"
android:hint="Message"
android:inputType=""
android:minHeight="48dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="224dp"
android:orientation="horizontal">
<Button
android:id="#+id/btnNext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Next" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="closeMethod"
android:text="CLose" />
</LinearLayout>
</RelativeLayout>
The issue is when I don't put any value into the firstEditText or secondEditText or both of them and click on any button then the app crashes and a pop up shows "myapp keeps stopping".
I cannot get the text and am unsure of why the app keeps crashing.
you have defined your Edit texts in the first activity with id's named
edtPhone
edtMessage
but there was no edtPhone or edtMessage in your xml.
this issue also repeats in your second activity
you have defined txtPhone and txtMessage
but again there are no such ids in your second activity XML.
keep in mind that these might not be the whole problem as you didn't post any log for the errors. but if there were anything else, ask and we'll help you
I am learning java and trying to register user's info in firebase realtime database when they register in the app ,but the data doesn't get stored in the database and the logcat shows no error so I can't figure out what's the problem.
P.S. - App is connected to the database & firebase database rules are:
{
"rules": {
".read": true,
".write": true
}
}
here's the SignUp.java file code
package com.example.foodapp;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import com.google.android.material.textfield.TextInputEditText;
import com.google.android.material.textfield.TextInputLayout;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class SignUp extends AppCompatActivity {
//variables
private TextInputLayout regName,regUsername,regEmail,regPhoneNo,regPassword;
private Button regBtn,regToLogInBtn;
FirebaseDatabase rootNode;
DatabaseReference reference;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up);
//hooks
regName = (TextInputLayout )findViewById(R.id.reg_name);
regUsername = (TextInputLayout )findViewById(R.id.reg_username);
regEmail = (TextInputLayout )findViewById(R.id.reg_email);
regPhoneNo = (TextInputLayout )findViewById(R.id.reg_phoneNo);
regPassword = (TextInputLayout )findViewById(R.id.reg_password);
regBtn = (Button)findViewById(R.id.reg_btn);
regToLogInBtn = (Button)findViewById(R.id.reg_login_btn);
//save data in firebase using button click
regBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
rootNode = FirebaseDatabase.getInstance();
reference = rootNode.getReference("users");
Log.d("HELLO", "Register Button Clicked");
//get all value from text fields
String name = regName.getEditText().getText().toString();
String username = regUsername.getEditText().getText().toString();
String email = regEmail.getEditText().getText().toString();
String phoneNo = regPhoneNo.getEditText().getText().toString();
String password = regPassword.getEditText().getText().toString();
UserHelperClass helperClass = new UserHelperClass(name, username, email, phoneNo, password);
reference.child(phoneNo).push().setValue(helperClass);
}
});
}
}
the xml codes are:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="fill_parent">
<LinearLayout 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=".SignUp"
android:orientation="vertical"
android:background="#fff"
android:padding="20dp">
<ImageView
android:layout_width="150dp"
android:layout_height="150dp"
android:src="#drawable/logo"
android:transitionName="logo_name"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Welcome"
android:textSize="40sp"
android:fontFamily="#font/bungee"
android:layout_marginTop="-20dp"
android:textColor="#000"
android:transitionName="logo_text"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="SignUp to start your new Journey"
android:textSize="18sp"
android:transitionName="logo_desc"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:layout_marginBottom="20dp"
android:orientation="vertical">
<com.google.android.material.textfield.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/reg_name"
android:hint="Full Name"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
>
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="text" />
</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/reg_username"
app:counterMaxLength="15"
android:hint="Username"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
android:transitionName="username_tran">
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="text" />
</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/reg_email"
android:hint="Email"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textEmailAddress" />
</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/reg_phoneNo"
android:hint="Phone Number"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="number" />
</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/reg_password"
android:hint="Password"
app:passwordToggleEnabled="true"
style="#style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
android:transitionName="password_tran">
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword" />
</com.google.android.material.textfield.TextInputLayout>
</LinearLayout>
<Button
android:id="#+id/reg_btn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000"
android:text="GO"
android:textColor="#fff"
android:transitionName="button_tran" />
<Button
android:id="#+id/reg_login_btn"
style="?android:attr/borderlessButtonStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#00000000"
android:text="Already have an account? Login"
android:textColor="#000"
android:transitionName="login_signup_tran" />
</LinearLayout>
</ScrollView>
```
the database is:
[1]: https://i.stack.imgur.com/IlaDs.png
you can refer to this question, after reading those answers, the reason of the issue is either you verification id or code is null or empty SHA certificates is not available on firebase app (console)
Exception when authenticating with wrong verification code
The app is supposed to call one screen from another and use the other screen's layout components. Whenever I try to call a component, such as ImageButton, it says that member id is unknown, I told my teacher and he says that it shouldn't happen. I have tried renaming the components and even made a new project.
How can I fix it?
the error is in R.id
package com.movil.ejemploventanas;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.ImageButton;
public class DatosPersonales extends Activity {
EditText vEdtNom,vEdtEdad;
ImageButton vBtnOrigen,vBtnSantuario;
Intent intnEnvio;
Bundle bndContenedorEnvio;
String strNom;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.datospersonales);
vEdtNom=(EditText)findViewById(R.id.edtNom);
vEdtEdad=(EditText)findViewById(R.id.edtEdad);
vBtnOrigen=(ImageButton)findViewById(R.id.btnOrigen);
vBtnSantuario=(ImageButton)findViewById(R.id.btnSantuario);
intnEnvio=new Intent(DatosPersonales.this,Caracteristicas.class);
bndContenedorEnvio=new Bundle();
vBtnOrigen.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0){
strNom=vEdtNom.getText().toString();
bndContenedorEnvio.putString("nom",strNom);
bndContenedorEnvio.putString("edad", vEdtEdad.getText().toString());
bndContenedorEnvio.putString("opc","1");
intnEnvio.putExtras(bndContenedorEnvio);
startActivity(intnEnvio);
}
});
vBtnSantuario.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0){
strNom=vEdtNom.getText().toString();
bndContenedorEnvio.putString("nom",strNom);
bndContenedorEnvio.putString("edad",vEdtEdad.getText().toString());
bndContenedorEnvio.putString("opc","2");
intnEnvio.putExtras(bndContenedorEnvio);
startActivity(intnEnvio);
}
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:id="#+id/txtLetrero"
style="style/titulo"
android:layout_centerHorizontal="true"
android:text="#string/letMariposa"/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/txtLetrero"
android:id="#+id/linearlayout1"
android:layout_centerHorizontal="true"
android:layout_marginTop="66dp">
<TextView
android:id="#+id/txtNom"
style="style/letreros"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="string/nom"/>
<EditText
android:id="#+id/edtNom"
style="style/datos"
android:layout_width="220dp"
android:layout_height="wrap_content"
android:inputType="textPersonName"/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/linearLayout1"
android:id="#+id/linearlayout2"
android:layout_centerHorizontal="true">
<TextView
android:id="#+id/txtEdad"
style="style/letreros"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="#string/edad"
android:textAlignment="gravity"/>
<EditText
android:id="#+id/edtEdad"
style="style/datos"
android:layout_width="220dp"
android:ems="10"
android:layout_height="wrap_content"
android:inputType="number"/>
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/origen"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_below="#+id/linearLayout2"
android:layout_marginLeft="30dp"
android:layout_marginTop="200dp"
android:id="#+id/textView4"
style="style/letreros"/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_below="#id/textView4"
android:layout_marginLeft="80dp"
android:id="#+id/btnOrigen"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/sant"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_below="#+id/btnOrigen"
android:layout_marginLeft="120dp"
android:id="#+id/textView5"
style="style/letreros"/>
<ImageButton
android:id="#+id/btnSantuario"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView5"
android:layout_marginLeft="180dp"/>
</RelativeLayout>
I am making a simple app in which context view changes and then a toast message is displayed as input given by user. I don't understand why the app keeps on crashing when changing the context view.
Also Android studio gives this warning:
Method "Toaster" is missing in "FirstActivity" or has incorrect signature.
Here is my code:
activity_me_clicked.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="#string/welcome"
android:textSize="36sp" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:paddingLeft="7dp"
android:paddingRight="7dp"
android:text="#string/intro"
android:textSize="24sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:baselineAligned="false">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="#+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="7dp"
android:layout_marginEnd="7dp"
android:layout_marginTop="10dp"
android:ems="10"
android:hint="Name"
android:inputType="textPersonName"
tools:ignore="HardcodedText" />
<Button
android:id="#+id/named"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingBottom="10dp"
android:paddingTop="10dp"
android:onClick="MainProcess"
android:text="#string/done" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal"
tools:ignore="UselessLeaf"></LinearLayout>
</LinearLayout>
</LinearLayout>
FirstActivity.Java:
package com.example.nautatvanavlakha.abcd;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
public class FirstActivity extends AppCompatActivity {
public static String owner_string;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_me_clicked);
}
public void MainProcess(View view) {
final String TAG="DEBUG";
Log.d(TAG,"At least process started");
EditText owner = (EditText) findViewById(R.id.name);
owner_string = owner.getText().toString();
Log.d(TAG,"owner name stored");
TextView textView = (TextView) findViewById(R.id.welcome);
textView.setText("Hi " + owner_string + ".");
Log.d(TAG,"owner name is set");
setContentView(R.layout.activity_main_screen);
Log.d(TAG,"content shown");
}
}
activity_main_screen.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/welcome"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/textView4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/what_would_you_like_me_to_do_today"
android:textSize="18sp" />
<Button
android:id="#+id/Cam"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:padding="0dp"
android:paddingTop="15dp"
android:text="#string/camera" />
<Button
android:id="#+id/Mus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:padding="0dp"
android:paddingTop="15dp"
android:text="#string/music" />
<Button
android:id="#+id/QR"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:padding="0dp"
android:paddingTop="15dp"
android:text="#string/scanQR" />
<EditText
android:id="#+id/toastText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/order"
android:inputType="textPersonName" />
<Button
android:id="#+id/toaster"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:onClick="toaster"
android:padding="0dp"
android:paddingTop="15dp"
android:text="#string/toast"
android:layout_marginEnd="100dp"
android:layout_gravity="center"/>
</LinearLayout>
MainScreen.java:
package com.example.nautatvanavlakha.abcd;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class MainScreen extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_screen);
}
public void toaster(View view){
EditText toast = (EditText)findViewById(R.id.toastText);
String final_toast = toast.getText().toString();
Toast.makeText(getApplicationContext(), final_toast, Toast.LENGTH_SHORT).show();
}
}
EDIT: As suggested, I moved the toaser function to FirstActivity.Java and deleted the MainScreen.java file as it becomes pointless to keep it. But the major problem is when I press the button (id named) the app keeps stopping.
EDIT2: I found that setContentView(R.layout.activity_main_screen) in FirstActivity.Java needs to be above this code
TextView textView = (TextView) findViewById(R.id.welcome);
textView.setText("Hi " + owner_string + ".");
Log.d(TAG,"owner name is set");
so that Activity has access to all the layout components. Thanks solved :)
You replaced the content view in the first activity with a layout that include the onClick attribute, but you have no public void toaster(View view) method there.
So, either don't use setContentView a second time, or implement that method on both Activities.
The recommended way to replace the view is Fragments, by the way
This is a wrong way to change the contents of your Activity, The main problem here is that you have onClick attribute set to "toaster", And you don't have a function called "toaster" in your FirstActivity.
Beside that, The MainScreen Activity in your code will never be used.
So, Your problem is that you set the FirstActivity contents to "activity_main_screen.xml", And FirstActivity doesn't have "toaster" method in it, When you change the context, the Activity will try to find toaster method and the app will crash because the method doesn't exist in FirstActivity.
You can solve this problem by making a method called "toaster" inside FirstActivity, But
This is a very bad practice, You can use Fragments instead, Or you can use Intent to move to another activity.
Some useful links about Fragments:
https://developer.android.com/guide/components/fragments.html
https://www.tutorialspoint.com/android/android_fragments.htm
https://examples.javacodegeeks.com/android/core/app/fragment/android-fragments-example/
Why should I use fragment in Android?
my code below is crashing. I am trying to have an app where the user inputs a word in the EditText and, after clicking the button, the app checks if the inputed word equals "hello", and if it does, the app takes the user to another activity.
The error is:
java.lang.IllegalStateException: Could not find method toHi (MainActivity)(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'button'
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
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.reynaldo.myapplication.MainActivity">
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/1"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="#+id/button"
android:onClick="toHi (MainActivity)" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="hi"
android:ems="10"
android:id="#+id/text"
android:layout_marginTop="15dp"
android:layout_below="#+id/button"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void toHi (View v){
EditText text = (EditText) findViewById(R.id.text);
String key = text.getText().toString();
if (key.equals("hello")){
Intent i = new Intent (this, Main2Activity.class);
startActivity(i);
}
}
}
The problem is with the value of onClick:
replace
android:onClick="toHi (MainActivity)"
with
android:onClick="toHi"
The problem is that your event specified in Button onClick is "toHi (MainActivity)" while you are defining method public void toHi(View view).
One thing more,there are circular dependencies in your xml file.You are specifiying layout_below in both button and edit text.
Code like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
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"
>
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="#+id/button"
android:layout_below="#+id/text" //Specify this here only
android:onClick="toHi" /> // Change here
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="hi"
android:ems="10"
android:id="#+id/text"
android:layout_marginTop="15dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>