title: My First App crashes when pressing a button
body: <p>I tried numerous times to make the app from the MyFirstApp Tutorial on developers.android (<a href="https://developer.android.com/training/basics/firstapp/index.html" rel="nofollow">https://developer.android.com/training/basics/firstapp/index.html</a>) work. I'm testing my code on a Nexus 4 device with Stock Android 4.4.2</p>
  
  <p>My +problem is that the app crashes everytime I press the send button and DisplayMessageActivity gets started. The most common cause for a crash of this tutorial app is that the DisplayMessageActivity was not included in the Android Manifest file, but it's definitly included in mine. I have no idea what causes this crash, so here is my full code including Logcat.</p>
  
  <p>AndroidManifest.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.myfirstapp"
  android:versionCode="1"
  android:versionName="1.0" &gt;
  
  &lt;uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="19" /&gt;
  
  &lt;application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
      &lt;activity
          android:name="com.example.myfirstapp.MainActivity"
          android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;activity
          android:name="com.example.myfirstapp.DisplayMessageActivity"
          android:label="@string/title_activity_display_message"
          android:parentActivityName="com.example.myfirstapp.MainActivity" &gt;
          &lt;meta-data
              android:name="android.support.PARENT_ACTIVITY"
              android:value="com.example.myfirstapp.MainActivity" /&gt;
      &lt;/activity&gt;
  &lt;/application&gt;
  </code></pre>
  
  <p></p>
  
  <p>MainActivity.java</p>
  
  <pre><code>package com.example.myfirstapp;
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.support.v7.app.ActionBarActivity;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.EditText;
  
  public class MainActivity extends ActionBarActivity {
  
  public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      if (savedInstanceState == null) {
          getSupportFragmentManager().beginTransaction()
                  .add(R.id.container, new         PlaceholderFragment()).commit();
      }
  }
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
  
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
  }
  
  @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);
  }
  
  /**
   * A placeholder fragment containing a simple view.
   */
  public static class PlaceholderFragment extends Fragment {
  
      public PlaceholderFragment() {
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
          View rootView = inflater.inflate(R.layout.fragment_main, container,
                  false);
          return rootView;
      }
  }
  
  public void sendMessage(View view) {
      Intent intent = new Intent(this, DisplayMessageActivity.class);
      EditText editText = (EditText) findViewById(R.id.enter_message);
      String message = editText.getText().toString();
      intent.putExtra(EXTRA_MESSAGE,message);
      startActivity(intent);
  }
   }
  </code></pre>
  
  <p>DisplayMessageActivity.java</p>
  
  <pre><code>package com.example.myfirstapp;
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.support.v7.app.ActionBarActivity;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.TextView;
  
   public class DisplayMessageActivity extends ActionBarActivity {
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      Intent intent = getIntent();
      String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
  
      TextView textView = new TextView(this);
      textView.setTextSize(40);
      textView.setText(message);      
      setContentView(textView);
  
      if (savedInstanceState == null) {
          getSupportFragmentManager().beginTransaction()
                  .add(R.id.container, new PlaceholderFragment()).commit();
      }
  }
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
  
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.display_message, menu);
      return true;
  }
  
  @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);
  }
  
  /**
   * A placeholder fragment containing a simple view.
   */
  public static class PlaceholderFragment extends Fragment {
  
      public PlaceholderFragment() {
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
          View rootView = inflater.inflate(R.layout.fragment_display_message,
                  container, false);
          return rootView;
      }
  }
  }
  </code></pre>
  
  <p>activity_main.xml</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/container"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="horizontal"
      tools:context="com.example.myfirstapp.MainActivity"
      tools:ignore="MergeRootFrame" &gt;
  
      &lt;EditText 
          android:id="@+id/enter_message"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:hint="@string/enter_message"/&gt;
  
     &lt;Button
         android:id="@+id/button_send"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/button_send"
         android:onClick="sendMessage"/&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>fragment_main.xml</p>
  
  <pre><code>&lt;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.myfirstapp.MainActivity$PlaceholderFragment" &gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>activity_display_message.xml</p>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/container"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context="com.example.myfirstapp.DisplayMessageActivity"
      tools:ignore="MergeRootFrame" /&gt;
  </code></pre>
  
  <p>fragment_display_message.xml</p>
  
  <pre><code>&lt;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.myfirstapp.DisplayMessageActivity$PlaceholderFragment" &gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>LogCat</p>
  
  <pre><code>03-18 15:27:35.195: E/AndroidRuntime(12382): FATAL EXCEPTION: main
  03-18 15:27:35.195: E/AndroidRuntime(12382): Process: com.example.myfirstapp, PID: 12382
  03-18 15:27:35.195: E/AndroidRuntime(12382): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myfirstapp/com.example.myfirstapp.DisplayMessageActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f05003c (com.example.myfirstapp:id/container) for fragment PlaceholderFragment{41e7f580 #0 id=0x7f05003c}
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread.access$800(ActivityThread.java:135)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.os.Handler.dispatchMessage(Handler.java:102)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.os.Looper.loop(Looper.java:136)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread.main(ActivityThread.java:5017)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at java.lang.reflect.Method.invokeNative(Native Method)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at java.lang.reflect.Method.invoke(Method.java:515)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at dalvik.system.NativeStart.main(Native Method)
  03-18 15:27:35.195: E/AndroidRuntime(12382): Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f05003c (com.example.myfirstapp:id/container) for fragment PlaceholderFragment{41e7f580 #0 id=0x7f05003c}
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:919)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:570)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.Activity.performStart(Activity.java:5241)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2168)
  03-18 15:27:35.195: E/AndroidRuntime(12382):    ... 11 more
  </code></pre>
  
  <p>It would be great if someone could spot the error which causes the crash and could me help out with the EditText. Thanks a lot in advance.</p>