Button wont work

Question

I have added a button from my second activity and third, but it gives an error when it is clicked on. Here is the first activity Java file.

package com.example.ephraimcohen.prestwichlanguageschool;

import android.content.Intent;
import android.provider.AlarmClock;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import static android.provider.AlarmClock.EXTRA_MESSAGE;

public class MainActivity extends AppCompatActivity {
    public static final String EXTRA_MESSAGE = AlarmClock.EXTRA_MESSAGE ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    /** Called when the user taps the Send button */
    public void sendMessage(View view) {
        Intent intent = new Intent(this, languageselection.class);
        EditText editText = (EditText) findViewById(R.id.editText);
        String message = editText.getText().toString();
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
    }
}

Here is the second Java file

package com.example.ephraimcohen.prestwichlanguageschool;

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import static android.provider.AlarmClock.EXTRA_MESSAGE;
import static android.support.v4.app.NotificationCompat.EXTRA_MESSAGES;

public class languageselection extends AppCompatActivity {


    public static final String EXTRA_MESSAGE ="extra_message";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_languageselection);

        // Get the Intent that started this activity and extract the string
        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        // Capture the layout's TextView and set the string as its text
        TextView textView = findViewById(R.id.textView);
        textView.setText(message);
    }

    /** Called when the user taps the Send button */
    public void sendMessage(View view) {
        Intent intent = new Intent(this, languageselection.class);
        EditText editText = (EditText) findViewById(R.id.editText);
        String message = editText.getText().toString();
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
    }
}

Here is the third Java file.

package com.example.ephraimcohen.prestwichlanguageschool;

        import android.app.Notification;
        import android.content.Intent;
        import android.support.v7.app.AppCompatActivity;
        import android.os.Bundle;
        import android.view.View;
        import android.widget.TextView;

        import java.util.Locale;

public class catagoryitalian extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_catagoryitalian);

        // Get the Intent that started this activity and extract the string
        Intent intent = getIntent();
        String message = intent.getStringExtra(languageselection.EXTRA_MESSAGE);

        // Capture the layout's TextView and set the string as its text
        TextView textView = findViewById(R.id.textView);
        textView.setText(message);
    }
}

I have managed to get the first page to connect to the second via a button, but the second-page won't allow me to go to the third page. I have put all the code in but it just restarts the app when the button on the second page is pressed. After restarting, it closes the app. Any advice would be really appreciated.

Second XML file

<?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.ephraimcohen.prestwichlanguageschool.languageselection">

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="0dp"
        android:layout_height="77dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/imageView3"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/logo" 
android:contentDescription="@string/todo" />

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="265dp"
        android:layout_marginStart="81dp"
        android:layout_marginTop="2dp"
        app:layout_constraintEnd_toStartOf="@+id/imageView2"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        app:srcCompat="@drawable/italianflag" android:contentDescription="@string/todo"
        android:layout_marginRight="265dp"
        android:layout_marginLeft="81dp" />

    <ImageView
        android:id="@+id/imageView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="@+id/imageView3"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.857"
        app:srcCompat="@drawable/polishflag" android:contentDescription="@string/todo" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="34dp"
        android:layout_marginTop="25dp"
        android:text="@string/italian"
        android:onClick="sendMessage"
        app:layout_constraintStart_toEndOf="@+id/imageView3"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        android:layout_marginLeft="34dp" />

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="22dp"
        android:layout_marginStart="34dp"
        android:text="@string/polish"
        app:layout_constraintBottom_toBottomOf="@+id/imageView4"
        app:layout_constraintStart_toEndOf="@+id/imageView4"
        android:layout_marginLeft="34dp" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="11dp"
        android:layout_marginStart="106dp"
        android:text="@string/choose_a_language"
        android:textAppearance="@style/TextAppearance.AppCompat.Display2"
        app:layout_constraintEnd_toStartOf="@+id/imageView2"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginRight="11dp"
        android:layout_marginLeft="106dp" />
</android.support.constraint.ConstraintLayout>

Stack trace

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.ephraimcohen.prestwichlanguageschool, PID: 30038
                  java.lang.IllegalStateException: Could not execute method for android:onClick
                      at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
                      at android.view.View.performClick(View.java:5640)
                      at android.view.View$PerformClick.run(View.java:22455)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6165)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)
                   Caused by: java.lang.reflect.InvocationTargetException
                      at java.lang.reflect.Method.invoke(Native Method)
                      at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
                      at android.view.View.performClick(View.java:5640) 
                      at android.view.View$PerformClick.run(View.java:22455) 
                      at android.os.Handler.handleCallback(Handler.java:751) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6165) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778) 
                   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                      at com.example.ephraimcohen.prestwichlanguageschool.languageselection.sendMessage(languageselection.java:39)
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
                      at android.view.View.performClick(View.java:5640) 
                      at android.view.View$PerformClick.run(View.java:22455) 
                      at android.os.Handler.handleCallback(Handler.java:751) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6165) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778) 
Application terminated.

Please add layout XML of 2nd activity and the exception log. — Christopher, Dec 27 '17 at 18:35
From the second class languageselection call the third class. Intent intent = new Intent(this, catagoryitalian.class); By the way pls post the error you are getting. — lib4backer, Dec 27 '17 at 18:39

score 1 · Answer 1 · answered Dec 27 '17 at 18:36

1

Your third activity's java class is catagoryitalian but in sendMessage method inside second activity's java class, you have passed the wrong class name in Intent

Intent intent = new Intent(this, languageselection.class);

Change it to

Intent intent = new Intent(this, catagoryitalian.class);

answered Dec 27 '17 at 18:36

Yousaf

27,861
6
44
69

I have changed that and the app is still not working – Ephraim Cohen Dec 27 '17 at 18:49
That would be because of another issue. For help with that, you need to post stack trace. – Yousaf Dec 27 '17 at 18:51
how do you do that – Ephraim Cohen Dec 27 '17 at 18:52

score 0 · Answer 2 · answered Dec 27 '17 at 18:35

0

In the class languageselection:

public void sendMessage(View view) {
    Intent intent = new Intent(this, catagoryitalian.class);
   ...
}

You are calling the same Activity instead of the third activity (as above).

answered Dec 27 '17 at 18:35

Anindya Dutta

1,972
2
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33

Button wont work

2 Answers2