Apps startActivity() causing crash

[Bbrian]

So I just started learning to develop Android apps, and I have a programming background (Python mainly), so I somewhat know what I'm doing. I'm having a problem with using startActivity(). I've commented code to figure out exactly where the error gets thrown, and it happens right as startActivity() is encountered. The error I get is from the emulator and it is just a popup window that says, "Unfortunately, Test has stopped." (Test is my program name) after I click my button. My code is this

package com.test.test;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class TestActivity extends Activity {
	
	public final static String EXTRA_MESSAGE = "com.test.test.MESSAGE";
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
    
    public class DisplayMessageActivity extends Activity {
    	@Override
    	public void onCreate(Bundle savedInstanceState){
    		super.onCreate(savedInstanceState);
    	}
    }

    public void sendMessage(View view) {
    	setContentView(R.layout.main);
    	Intent intent = new Intent(this, DisplayMessageActivity.class);
    	EditText editText = (EditText) findViewById(R.id.textBox1);
    	String message = editText.getText().toString();
    	intent.putExtra(EXTRA_MESSAGE, message);
    	startActivity(intent);
    }

}

My xml is here

<?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:orientation="horizontal" >
    
    <EditText android:id="@+id/textBox1"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="@string/textBox1Hint" />
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button1"
        android:onClick="sendMessage" />   
    
</LinearLayout>

and my Manifest is here

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.test"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".TestActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <activity
            android:name="test.test.DisplayMessageActivity" 
            android:label="Message" >
        </activity>
        
    </application>
</manifest>

Any help would be greatly greatly appreciated. I just don't get what is wrong.

 

[cr5315]

Are you trying to get the text you sent with putExtra?
If so you should do it like this in your DisplayMessageActivity where you have

Intent intent = getIntent();

Bundle extras = getIntent().getExtras();
String message = "";
if (extras != null) {
    message = extras.getString(EXTRA_MESSAGE);

 

[Bbrian]

Yes, I am trying to do that eventually, but that isn't my problem really. The problem is that my program crashes seemingly without reason when it tries to do startActivity(intent)

I see that a lot of other people who had this same problem resolved it by adding their activity that they are calling to the manifest, but I believe I have done this correctly.

I might have confused you by not posting my entire code. I just updated it to include everything.

 

[wubbzy]

it is useful to post LogCat messages when you're asking for help with crashes/ANR etc.

Since you're learning it is good idea to build it into your practice the suggestion made by @cr5315, its just a safety cache technique and a good one, intents arriving from 'neither-world' can be null.

Now you've got to do few of things

1: Move DisplayMessageActivity into file of its own call it DisplayMessageActivity.java and package name on top should be com.test.test;
2: PS: Your DisplayMessageActivity is a empty class i.e. it does nothing after it is created;
3: Change your manifest file to point to .DisplayMessageActivity (assuming com.test.test is your package name resides and your java file layout an manifest 'package=' line follows the same convention).

give it a go and let us know

 

[Bbrian]

Perfect thanks I know it's an empty class. I was just trying to get it to change activities before I made the class do anything. Everything is working great now.