Android：设置媒体路由按钮时发生崩溃

Question

我和Android: Cast SDK v3 Crashing in Release build only有几乎相同的问题。 关键的区别是，我的项目做它，而我只是在调试但它在这一行

CastButtonFactory.setUpMediaRouteButton(getApplicationContext(), mMediaRouteButton); 

我试图让我的所有变量公开，但并不做任何事情。完整的代码是

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    mMediaRouteButton = (MediaRouteButton) findViewById(R.id.media_route_button); 
    CastButtonFactory.setUpMediaRouteButton(getApplicationContext(), mMediaRouteButton); 

    mCastContext = CastContext.getSharedInstance(this); 

    mSelector = new MediaRouteSelector.Builder() 
      // These are the framework-supported intents 
      .addControlCategory(MediaControlIntent.CATEGORY_LIVE_AUDIO) 
      .addControlCategory(MediaControlIntent.CATEGORY_LIVE_VIDEO) 
      .addControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK) 
      .build(); 
    mMediaRouter = MediaRouter.getInstance(this); 
} 

此外，我觉得它值得一提的是，此代码工作，我不能为我的生活找不出什么原因造成的停止工作。据我所知，当我在Android Studio中使缓存失效时停止工作。 这是我得到

错误

java.lang.RuntimeException: Unable to start activity ComponentInfo{mypackage.package/mypackage.package.MainActivity}: java.lang.IllegalStateException: Failed to initialize CastContext. 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6077) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
    Caused by: java.lang.IllegalStateException: Failed to initialize CastContext. 
    at com.google.android.gms.cast.framework.CastContext.zzbb(Unknown Source) 
    at com.google.android.gms.cast.framework.CastContext.getSharedInstance(Unknown Source) 
    at com.google.android.gms.cast.framework.CastButtonFactory.setUpMediaRouteButton(Unknown Source) 
    at mypackage.package.MainActivity.onCreate(MainActivity.java:51) 
    at android.app.Activity.performCreate(Activity.java:6664) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)  
    at android.app.ActivityThread.-wrap12(ActivityThread.java)  
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)  
    at android.os.Handler.dispatchMessage(Handler.java:102)  
    at android.os.Looper.loop(Looper.java:154)  
    at android.app.ActivityThread.main(ActivityThread.java:6077)  
    at java.lang.reflect.Method.invoke(Native Method)  
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)  
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)  
    Caused by: java.lang.IllegalAccessException: java.lang.Class<mypackage.package.CastOptionsProvider> is not accessible from java.lang.Class<com.google.android.gms.cast.framework.CastContext> 
    at java.lang.Class.newInstance(Native Method) 
    at com.google.android.gms.cast.framework.CastContext.zzbb(Unknown Source)  
    at com.google.android.gms.cast.framework.CastContext.getSharedInstance(Unknown Source)  
    at com.google.android.gms.cast.framework.CastButtonFactory.setUpMediaRouteButton(Unknown Source)  
    at mypackage.package.MainActivity.onCreate(MainActivity.java:51)  
    at android.app.Activity.performCreate(Activity.java:6664)  
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)  
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)  
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)  
    at android.app.ActivityThread.-wrap12(ActivityThread.java)  
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)  
    at android.os.Handler.dispatchMessage(Handler.java:102)  
    at android.os.Looper.loop(Looper.java:154)  
    at android.app.ActivityThread.main(ActivityThread.java:6077)  
    at java.lang.reflect.Method.invoke(Native Method)  
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)  
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)  

Answer 1

这是固定通过使CastOptionsProvider公众。我不知道为什么会出现这个问题，因为直到它没有公开才公布，它工作的很好。我没有碰到它开始失败的构建上的CastOptionsProvider。 我CastOptionsProvider现在看起来是这样

public class CastOptionsProvider implements OptionsProvider { 
@Override 
public CastOptions getCastOptions(Context appContext) { 
    CastOptions castOptions = new CastOptions.Builder() 
      .setReceiverApplicationId(appContext.getString(R.string.app_id)) 
      .build(); 
    return castOptions; 
} 
@Override 
public List<SessionProvider> getAdditionalSessionProviders(Context context) { 
    return null; 
} 
} 

Answer 2

有可能是你如何初始化媒体CastContext，正确初始化CastContext的问题，应用程序必须有工具OptionsProvider接口：

包com。示例。应用程序;

public class CastOptionsProvider implements OptionsProvider { 
    @Override 
    public CastOptions getCastOptions(Context appContext) { 
     ... 
    } 
} 

，并在AndroidManifest.xml与关键OPTIONS_PROVIDER_CLASS_NAME_KEY:

... 
    <meta-data 
     android:name="com.google.android.gms.cast.framework.OPTIONS_PROVIDER_CLASS_NAME" 
     android:value="com.example.app.CastOptionsProvider" /> 
    ... 

注指定其全限定类名：所有的公共方法必须从主线程调用。

我做了一些研究，发现这种相关SO票，其讨论如何初始化CastContext：How to initialize CastContext outside of onCreate method

Answer 3

如果这是在释放buildtype那么它是proguard的相关仅发生。请CastOptionsProvider类添加到ProGuard的文件，并重新检查

-keep class abc.xyz.videocast.CastOptionsProvider { *; } 

更多的安全，这些类也可以添加

-keep class android.support.** { *; } 
-keep class com.google.** { *; }