java - 转换按钮未显示

我正在尝试使用Android Studio创建ChomeCast发送器应用程序。我已经实现了所有代码，需要能够添加“投射按钮”，但是它不可用

这是我的代码。

build.gradle

    apply plugin: 'android'

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.3"

    defaultConfig {
        minSdkVersion 10
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:19.+'
    compile 'com.google.android.gms:play-services:4.3.+'
    compile 'com.android.support:mediarouter-v7:19.+'



}

RES /菜单/ main.xml

    <menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.example.castbuttontest.app.MainActivity" >


    <item
        android:id="@+id/media_route_menu_item"
        android:title="@string/media_route_menu_title"
        app:actionProviderClass="android.support.v7.app.MediaRouteActionProvider"
        app:showAsAction="always"/>
</menu>

MainActivity.java

    package com.example.castbuttontest.app;

    import android.support.v4.view.MenuItemCompat;
    import android.support.v7.app.ActionBarActivity;
    import android.os.Bundle;
    import android.support.v7.app.MediaRouteActionProvider;
    import android.support.v7.media.MediaRouteSelector;
    import android.support.v7.media.MediaRouter;
    import android.view.Menu;
    import android.view.MenuItem;

import com.google.android.gms.cast.Cast;
import com.google.android.gms.cast.CastDevice;
import com.google.android.gms.cast.CastMediaControlIntent;
import com.google.android.gms.common.api.GoogleApiClient;


public class MainActivity extends ActionBarActivity {


    MediaRouter mediaRouter;
    MediaRouteSelector mediaRouteSelector;
    MediaRouter.Callback myMediaRouterCallBack = new MediaRouter.Callback() {
        @Override
        public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo route) {
            CastDevice device = CastDevice.getFromBundle(route.getExtras());

        }

        @Override
        public void onRouteUnselected(MediaRouter router, MediaRouter.RouteInfo route) {
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        String APP_ID = "F6D3E50B";
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mediaRouter = MediaRouter.getInstance(this);
        mediaRouteSelector = new MediaRouteSelector.Builder()
                //.addControlCategory(CastMediaControlIntent.categoryForCast(APP_ID))
                .addControlCategory(CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID)
                .build();
    }

    @Override
    protected void onStart() {
        super.onStart();
        mediaRouter.addCallback(mediaRouteSelector, myMediaRouterCallBack,MediaRouter.CALLBACK_FLAG_PERFORM_ACTIVE_SCAN);
    }

    @Override
    protected void onStop() {
        mediaRouter.removeCallback(myMediaRouterCallBack);
        super.onStop();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem mediaRouterItem = menu.findItem(R.id.media_route_menu_item);
        MediaRouteActionProvider provider = (MediaRouteActionProvider) MenuItemCompat.getActionProvider(mediaRouterItem);
        provider.setRouteSelector(mediaRouteSelector);

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        return super.onOptionsItemSelected(item);
    }

}

您能告诉问题出在哪里吗？
提前致谢

编辑:
我终于解决了这个问题。我创建了一个新的Empty项目，并按照Sender App教程(Link)重新编写了代码:

MainActivity.java

    /*
   Copyright 2014 Charles-Eugene LOUBAO

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */

package cf.charly1811.android.sample.MediaRouteProvider;

import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.MediaRouteActionProvider;
import android.support.v7.media.MediaRouteSelector;
import android.support.v7.media.MediaRouter;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import com.google.android.gms.cast.CastDevice;
import com.google.android.gms.cast.CastMediaControlIntent;


public class MainActivity extends ActionBarActivity {
    /**
     * This sample shows how to add the Cast Button to the action bar using MediaRouterProvider
     * @see "https://developers.google.com/cast/docs/android_sender"
     */
    public static final String TAG = MainActivity.class.getSimpleName();
    String APP_ID = "F6D3E50B";

    MediaRouter mediaRouter;
    MediaRouteSelector mediaRouteSelector;
    MediaRouter.Callback mMediaRouterCallback;
    CastDevice mCastDevice;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mediaRouter = MediaRouter.getInstance(this);
        mediaRouteSelector = new MediaRouteSelector.Builder()
                .addControlCategory(CastMediaControlIntent.categoryForCast(APP_ID))
                .build();

        mMediaRouterCallback = new MediaRouter.Callback() {
            @Override
            public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo route) {
                super.onRouteSelected(router, route);
                Log.d(TAG, "Connected to "+ route.getName());
                mCastDevice = CastDevice.getFromBundle(route.getExtras());
                Toast.makeText(getApplicationContext(), "Connected to "+route.getName(),Toast.LENGTH_LONG).show();
            }

            @Override
            public void onRouteUnselected(MediaRouter router, MediaRouter.RouteInfo route) {
                super.onRouteUnselected(router, route);
                mCastDevice = null;
            }
        };
    }


    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG, "onResume");
        mediaRouter.addCallback(mediaRouteSelector,mMediaRouterCallback,MediaRouter.CALLBACK_FLAG_PERFORM_ACTIVE_SCAN);
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "onPause");
        if(isFinishing())
        {
            mediaRouter.removeCallback(mMediaRouterCallback);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem media_route_menu_item = menu.findItem(R.id.media_route_menu_item);
        MediaRouteActionProvider provider = (MediaRouteActionProvider) MenuItemCompat.getActionProvider(media_route_menu_item);
        provider.setRouteSelector(mediaRouteSelector);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        /*
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        */
        return super.onOptionsItemSelected(item);
    }
}

现在，它可以正常工作了。图标现已可用，我可以连接到我的Chromecast。我不确定，但我认为问题出在MediaRouter.Callback的实例上。

PS:我已将完整代码上传到GitHub上。您可以检查出来。 (Link)

最佳答案

从头开始重写所有内容实际上并没有向任何人显示问题出在哪里...

你有
.addControlCategory(CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID)
代替
.addControlCategory(CastMediaControlIntent.categoryForCast(CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID))
您正在将APP_ID直接传递到类别。我猜类别具有特殊格式，而APP_ID并非完全如此。我犯了同样的错误。 :)