Android 添加媒体路由器强制转换按钮时出错

我尝试使用实现我的应用程序的强制转换功能。 当它尝试将“媒体路由器播放”按钮添加到操作栏时，出现以下错误：

10-03 19:33:20.098  11781-11781/de.resper.e2cast W/MenuItemCompat﹕ getActionProvider: item does not implement SupportMenuItem; returning null
10-03 19:33:20.098  11781-11781/de.resper.e2cast W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41ebde18)
10-03 19:33:20.098  11781-11781/de.resper.e2cast E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: de.resper.e2cast, PID: 11781
java.lang.NullPointerException
at com.google.sample.castcompanionlibrary.cast.BaseCastManager.addMediaRouterButton(BaseCastManager.java:355)
at de.resper.e2cast.ChannelCastActivity.onCreateOptionsMenu(ChannelCastActivity.java:655)

CAHNNELCASTACITY中的位置为：

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    getMenuInflater().inflate(R.menu.main, menu);
    mCastManager.addMediaRouterButton(menu, R.id.media_route_menu_item); <--- ERROR
    return true;
}

并扩展为：

public class ChannelCastActivity extends ActionBarActivity

BaseCastManager中有错误行：

public MenuItem addMediaRouterButton(Menu menu, int menuResourceId) {
    MenuItem mediaRouteMenuItem = menu.findItem(menuResourceId);
    MediaRouteActionProvider mediaRouteActionProvider = (MediaRouteActionProvider) MenuItemCompat.getActionProvider(mediaRouteMenuItem);
    mediaRouteActionProvider.setRouteSelector(mMediaRouteSelector); <--- ERROR
    if (null != getMediaRouteDialogFactory()) {
        mediaRouteActionProvider.setDialogFactory(getMediaRouteDialogFactory());
    }
    return mediaRouteMenuItem;
}

public菜单项addMediaRouterButton（菜单项，int菜单源ID）{
MenuItem mediaRouteMenuItem=menu.findItem（menuResourceId）；
MediaRouteActionProvider MediaRouteActionProvider=（MediaRouteActionProvider）MenuItemCompat.getActionProvider（mediaRouteMenuItem）；
mediaRouteActionProvider.setRouteSelector（mMediaRouteSelector）；确保您的菜单项具有操作视图，而非-Chromecast需要支持v7版本。
您可以发布您的
R.menu.main
？Thx。选中所有菜单，但不选中菜单xml。您需要帮助，将在5分钟内接受答案。
public MenuItem addMediaRouterButton(Menu menu, int menuResourceId) {
    MenuItem mediaRouteMenuItem = menu.findItem(menuResourceId);
    MediaRouteActionProvider mediaRouteActionProvider = (MediaRouteActionProvider) MenuItemCompat.getActionProvider(mediaRouteMenuItem);
    mediaRouteActionProvider.setRouteSelector(mMediaRouteSelector); <--- ERROR
    if (null != getMediaRouteDialogFactory()) {
        mediaRouteActionProvider.setDialogFactory(getMediaRouteDialogFactory());
    }
    return mediaRouteMenuItem;
}

    <activity
        android:name=".ChannelCastActivity"
        android:label="@string/title_activity_channel_cast"
        android:theme="@style/Theme.AppCompat.Light"
        android:parentActivityName=".MainActivity" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="de.resper.e2cast.MainActivity" />
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
    </activity>