问在GCM onMessageReceived上显示警报对话框？

EN

public class MyGcmListenerService extends GcmListenerService {

  @Override
  public void onMessageReceived(String from, Bundle data) {
    Intent dialogIntent = new Intent(this, DialogActivity.class);
    dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    dialogIntent.putExtra(DialogActivity.TITLE, title);
    dialogIntent.putExtra(DialogActivity.MESSAGE, message);
    startActivity(dialogIntent);
  }

}

10-19 17:08:48.446 8657-8657/? E/AndroidRuntime: FATAL EXCEPTION: main
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{de.majestella/de.majestella.gcm.DialogActivity}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2092)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2117)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.access$700(ActivityThread.java:134)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1218)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:137)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4867)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:511)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1007)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:774)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:  Caused by: android.util.AndroidRuntimeException: requestFeature() must be called before adding content
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at com.android.internal.policy.impl.PhoneWindow.requestFeature(PhoneWindow.java:275)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.Activity.requestWindowFeature(Activity.java:3264)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at de.majestella.gcm.DialogActivity.onCreate(DialogActivity.java:24)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:5047)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2056)
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2117) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.access$700(ActivityThread.java:134) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1218) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:137) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4867) 
10-19 17:08:48.446 8657-8657/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)