为什么我的 MediaRouteButton 无法找到任何投射设备？

Question

以下是我在主要活动中的代码

public class MainActivity extends ActionBarActivity{
private MediaRouteButton mMediaRouteButton;
private MediaRouteSelector mMediaRouteSelector;
private MediaRouter mMediaRouter;
private CastDevice mSelectedDevice;
private MyMediaRouterCallback mMediaRouterCallback;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if(this.checkGooglePlaySevices(this))
        Log.v("cc5zhenhua","googleplayservice okay");
    else
    {
        Log.v("cc5zhenhua","googleplayservice not ok");
        //GooglePlayServicesUtil.getErrorDialog(0, this, 0).show();
    }
    //initialize media cast objects
     mMediaRouter=MediaRouter.getInstance(getApplicationContext());      
     mMediaRouteSelector=new MediaRouteSelector.Builder()
     .addControlCategory(CastMediaControlIntent.CATEGORY_CAST).build();      
     mMediaRouterCallback= new MyMediaRouterCallback();
     mMediaRouter.addCallback(mMediaRouteSelector, mMediaRouterCallback);    
}

public void onStart() {
    super.onStart();
    mMediaRouter.addCallback(mMediaRouteSelector, mMediaRouterCallback
            );
    MediaRouter.RouteInfo route = mMediaRouter.updateSelectedRoute(mMediaRouteSelector);
    // do something with the route...
}
@Override
protected void onResume()
{
    super.onResume();
    mMediaRouter.addCallback(mMediaRouteSelector, mMediaRouterCallback);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    super.onCreateOptionsMenu(menu);

    //mMediaRouteButton.setRouteSelector(mMediaRouteSelector);
    return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu){
    getMenuInflater().inflate(R.menu.main, menu);
    MenuItem mediaRouteItem = menu.findItem( R.id.action_mediaroute01 );
    MediaRouteActionProvider mediaRouteActionProvider =
            (MediaRouteActionProvider)MenuItemCompat.getActionProvider(
                    mediaRouteItem);
    mediaRouteActionProvider.setRouteSelector(mMediaRouteSelector);
    mMediaRouteButton = (MediaRouteButton) mediaRouteItem.getActionView();
    return true;}

 public  boolean checkGooglePlaySevices(final Activity activity) {
        final int googlePlayServicesCheck = GooglePlayServicesUtil.isGooglePlayServicesAvailable(
                activity);
        switch (googlePlayServicesCheck) {
            case ConnectionResult.SUCCESS:
                return true;
            default:
               Log.v("cc5zhenhua","test");          }
        return false;
 }
private class MyMediaRouterCallback extends MediaRouter.Callback 
{
  @Override
  public void onRouteSelected(MediaRouter router, RouteInfo info) {
    mSelectedDevice = CastDevice.getFromBundle(info.getExtras());
    String routeId = info.getId();
    Log.v("cc5zhenhua", "MainActivity.onRouteSelected");        
  }
  @Override
  public void onRouteUnselected(MediaRouter router, RouteInfo info) {
    //teardown();
    mSelectedDevice = null;
  }
}

}

没有构建错误。但是，当我运行主要活动时，根本无法单击媒体路由按钮。请告知我错过的任何地方？谢谢！

在新 SDK 发布之前，我的 chromecast 已通过 APPID 注册到白名单中。 我也不能将该 appID 用于控件类别，它会引发 not valida appID 异常。

我的投射设备也可用于我电脑中的 chromecast 扩展。

Answer 1

终于找到问题点了。只是因为我最后一个使用旧 googlecast sdk 的应用程序在 AVD 上运行，所以我专注于我的代码和新的 SDK 设置。但是，当我在真机上部署应用程序时，可以找到媒体路由。感谢 Ali 的善意和帮助。

Answer 2

您需要通过添加回调来开始扫描：

mMediaRouter.addCallback(mMediaRouteSelector, mMediaRouterCallback, MediaRouter.CALLBACK_FLAG_PERFORM_ACTIVE_SCAN);

如果您已经这样做了，但忘记在帖子中提及，那么您需要在开发者控制台上注册您的应用和设备。那么，您的问题很可能是由于您的设备被列入白名单；尝试从http://<chromecast-ip>:9222 的 chrome 浏览器连接到您的设备，如果不能，则您的设备未列入白名单；按照post 中的步骤进行故障排除