title: Null Pointer Exception with setOnClickListener()
body: <p>I sometimes get a null pointer exception with my code. Oddly enough, this does not happen every time, and I'm not sure why. Help?</p>
  
  <pre><code>package net.obviam.droidz;
  public class HomeView extends Activity {
      public void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
  
  
  
       setContentView(R.layout.menu);
  
  
  
      Button page1 = (Button) findViewById(R.id.Button01);
           page1.setOnClickListener(new View.OnClickListener() {
                   public void onClick(View view) {
  //                   Intent i = getIntent();
                       Intent myIntent = new Intent(view.getContext(), DroidzActivity.class);
                       startActivityForResult(myIntent, 0);
                   }
  
       });
  
  
  }
  
  
  
  protected void onDestroy() {
  //      Log.d(TAG, "Destroying..");
          super.onDestroy();
      }
      @Override
      protected void onStop() {
  //      Log.d(TAG, "Stopping...");
          super.onStop();
      }
  
  }
  </code></pre>
  
  <p>The logcat says that the problem is with line 19, the setOnClickListener. I'm not sure what's wrong with it though. It doesn't appear to be referencing anything.</p>
  
  <p>The Logcat reads like this:</p>
  
  <pre><code>02-17 16:52:13.816: E/AndroidRuntime(23756): FATAL EXCEPTION: main
  02-17 16:52:13.816: E/AndroidRuntime(23756): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.obviam.droidz/net.obviam.droidz.HomeView}: java.lang.NullPointerException
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.os.Handler.dispatchMessage(Handler.java:99)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.os.Looper.loop(Looper.java:130)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread.main(ActivityThread.java:3687)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at java.lang.reflect.Method.invokeNative(Native Method)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at java.lang.reflect.Method.invoke(Method.java:507)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at dalvik.system.NativeStart.main(Native Method)
  02-17 16:52:13.816: E/AndroidRuntime(23756): Caused by: java.lang.NullPointerException
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at net.obviam.droidz.HomeView.onCreate(HomeView.java:19)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
  02-17 16:52:13.816: E/AndroidRuntime(23756):    ... 11 more
  </code></pre>
  
  <p>And here is the manifest file:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="net.obviam.droidz"
  android:versionCode="1"
  android:versionName="1.0" &gt;
  
  &lt;uses-sdk android:minSdkVersion="10" /&gt;
  
  &lt;application
      android:icon="@drawable/images"
      android:label="@string/app_name" android:debuggable="true"&gt;
      &lt;activity android:name=".HomeView" 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=".DroidzActivity"&gt;&lt;/activity&gt;
  
  &lt;/application&gt;
  </code></pre>
  
  <p></p>
  
  <p>And here is the xml file that the button is found in:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
  
   &lt;Button android:text="Start Game!"
          android:id="@+id/Button01"
          android:layout_width="250dp"
          android:textSize="18dp"
          android:layout_height="55dp"&gt;
      &lt;/Button&gt;
  
  
  
  &lt;/LinearLayout&gt;
  </code></pre>