java – MediaController – 调用Show()时出错

我有这个代码用于显示MediaController,但是当我调用Show()方法时,它给了我一个致命的错误.

MediaPlayer本身处理Service并从MediaPlayerControl接口获取Intent.

我的代码：

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

            mediaController =  new MediaController(this, false);
            mediaController.setMediaPlayer(mediaPlayerControl);
            mediaController.setAnchorView(findViewById(R.id.mediaController));
            mediaController.setEnabled(true);
            mediaController.show(0);
    }

    //implements MediaPlayerControl interface
    private MediaPlayerControl mediaPlayerControl = new MediaPlayerControl()
    {

            //Override the methods to send Intent to the MediaPlayer Service
            ....
            ....
     };

我的logcat：

07-27 11:03:07.365: E/AndroidRuntime(328): FATAL EXCEPTION: main
07-27 11:03:07.365: E/AndroidRuntime(328): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.radius100fm/com.example.radius100fm.MainActivity}: android.view.WindowManager$BadTokenException: Unable to add window — token null is not valid; is your activity running?
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.os.Handler.dispatchMessage(Handler.java:99)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.os.Looper.loop(Looper.java:123)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread.main(ActivityThread.java:3683)
07-27 11:03:07.365: E/AndroidRuntime(328): at java.lang.reflect.Method.invokeNative(Native Method)
07-27 11:03:07.365: E/AndroidRuntime(328): at java.lang.reflect.Method.invoke(Method.java:507)
07-27 11:03:07.365: E/AndroidRuntime(328): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-27 11:03:07.365: E/AndroidRuntime(328): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-27 11:03:07.365: E/AndroidRuntime(328): at dalvik.system.NativeStart.main(Native Method)
07-27 11:03:07.365: E/AndroidRuntime(328): Caused by: android.view.WindowManager$BadTokenException: Unable to add window — token null is not valid; is your activity running?
07-27 11:03:07.365: E/AndroidRuntime(328): at android.view.ViewRoot.setView(ViewRoot.java:527)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.view.Window$LocalWindowManager.addView(Window.java:424)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.widget.MediaController.show(MediaController.java:304)
07-27 11:03:07.365: E/AndroidRuntime(328): at com.example.radius100fm.MainActivity.onCreate(MainActivity.java:100)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-27 11:03:07.365: E/AndroidRuntime(328): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
07-27 11:03:07.365: E/AndroidRuntime(328): … 11 more

我的代码有什么问题？

解决方法:

使用此方法.

@Override
public void onWindowFocusChanged(boolean hasFocus) {
   super.onWindowFocusChanged(hasFocus);
   if(mediaController != null)
      mediaController.show(0);
}

标签：java,android,android-mediaplayer,mediacontroller
来源： https://codeday.me/bug/20190624/1283167.html