Android 集成 Google Cast 异常问题-六虎

GoogleCast 异常问题

项目中集成 Google Cast 功用时，部分机型遇到一些问题

需求

项目中Cast需求有点特别，默认Cast Button处于不可见状况。 APP进入前台时，查询周围是否有可用Cast设备，有才显现Cast Button, 否则躲藏

依据流程，咱们有两种状况需求处理

Fragment/Activity 发动时查询Available Cast Devices，`暂命名办法1`

代码完成如下： Fragment -> onResume(), checkCastDevices:

    public static boolean checkCastDevice(Context activity) {
        MediaRouter mediaRouter = MediaRouter.getInstance(activity);
        List<mediarouter.routeinfo> routes = mediaRouter.getRoutes();
        if (routes != null &amp;&amp; routes.size() != 0) {
            for (MediaRouter.RouteInfo info : routes) {
                if (info.getDeviceType() != MediaRouter.RouteInfo.CONNECTION_STATE_DISCONNECTED
                        && !info.isDefault() && !info.isBluetooth() && !info.isDeviceSpeaker()) {
                    return true;
                }
            }
        }
        return false;
    }

Fragment/Activity 处于前台时，动态获取Availabe Cast Devices， `暂命名办法2`

监听了addCastStateListener CastContext.addCastStateListener(this)


    @Override
    public void onCastStateChanged(int i) {
        stateListenerListTemp.clear();
        stateListenerListTemp.addAll(stateListenerList);
        switch (i) {
            case CastState.CONNECTED:
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.connected();
                }
                break;
            case CastState.CONNECTING:
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.connecting();
                }
                break;
            case CastState.NO_DEVICES_AVAILABLE:  //has not available devices
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.noDevicesAvailable();  // hide cast button
                }
                break;
            case CastState.NOT_CONNECTED:  //has available devices, but not connect
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.notConnected();  // show cast button
                }
                break;
        }
        stateListenerListTemp.clear();
    }

依据上述完成，能够即时监听Cast Devices的改变，动态更新Cast Button的可见性

问题

新增了一个有个需求， Toolbar上新增了一个视图，需求依据Cast Button的可见性来设置视图可见性，即二者可见性互斥，但在测验中发现一些问题。

部分设备上，例如Remi Note 4，上述两个办法都无效

问题1，办法1 只有在进程毁掉后第一次发动能够获取周围Available Cast Devices，之后封闭APP重启一向返回false
问题2，办法2 APP处于前台时，断开WIFI时，Cast Button消失，从头衔接WIFI，Cast Button可见，但代码中并没有收到Cast Devices 状况更新的回调，设置Cast Button Visibility的代码并未履行，这就呈现一种状况：虽然Cast Button不可见，可是新增的视图却并未显现。

分析

问题1

当App进程毁掉后从头发动，能够成功获取Cast Devices，阐明初始化CastContext时，自动扫描了周边Routes, 而App封闭后从头翻开，部分设备未自动扫描，所以获取状况失利。

问题2

当Cast Button可见时，断开WIFI衔接，因为没有收到onCastStateChanged的回调，CastButton.SetVisibility(View.GONE)并未履行, 可是Cast Button 却不可见了，翻开Developers options–Show layouts bounds开关，发现Cast Button 在布局中存在，可是图标却不可见，那么有两种可能：
– Cast Button的Drawable 被移除了
– Cast Button被设为View.INVISIBLE

可是onCastStateChanged的回调并未履行，可是Cast Button 状况却有改变，那只能阐明Cast Button内部监听了衔接状况的改变，并内部处理了展现状况。

项目中Cast Button是一个MediaRouteButton，查询源码

public class MediaRouteButton extends View {
    private static final String TAG = "MediaRouteButton";
    private static ConnectivityReceiver sConnectivityReceiver;
    private int mVisibility = VISIBLE;
    private boolean mAlwaysVisible;
    public MediaRouteButton(Context context) {
        this(context, null);
    }
    public MediaRouteButton(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.mediaRouteButtonStyle);
    }
    public MediaRouteButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(MediaRouterThemeHelper.createThemedButtonContext(context), attrs, defStyleAttr);
        if (sConnectivityReceiver == null) {
            sConnectivityReceiver = new ConnectivityReceiver(context.getApplicationContext());
        }
    }
    @Override
    public void onAttachedToWindow() {
        super.onAttachedToWindow();
        sConnectivityReceiver.registerReceiver(this);
    }
    @Override
    public void onDetachedFromWindow() {
        if (!isInEditMode()) {
            sConnectivityReceiver.unregisterReceiver(this);
        }
        super.onDetachedFromWindow();
    }
    void refreshVisibility() {
        //set VISIBLE or INVISIBLE
        super.setVisibility(mVisibility == VISIBLE
                && !(mAlwaysVisible || sConnectivityReceiver.isConnected())
                ? INVISIBLE : mVisibility);
    }
    /**
    * 监听衔接状况的改变，改写MediaRouteButton可见性
    */
    private static final class ConnectivityReceiver extends BroadcastReceiver {
        private final Context mContext;
        // If we have no information, assume that the device is connected
        private boolean mIsConnected = true;
        private List<MediaRouteButton> mButtons;
        ConnectivityReceiver(Context context) {
            mContext = context;
            mButtons = new ArrayList<MediaRouteButton>();
        }
        public void registerReceiver(MediaRouteButton button) {
            if (mButtons.size() == 0) {
                IntentFilter intentFilter = new IntentFilter();
                intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
                mContext.registerReceiver(this, intentFilter);
            }
            mButtons.add(button);
        }
        public void unregisterReceiver(MediaRouteButton button) {
            mButtons.remove(button);
            if (mButtons.size() == 0) {
                mContext.unregisterReceiver(this);
            }
        }
        public boolean isConnected() {
            return mIsConnected;
        }
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
                boolean isConnected = !intent.getBooleanExtra(
                        ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
                if (mIsConnected != isConnected) {
                    mIsConnected = isConnected;
                    for (MediaRouteButton button: mButtons) {
                        button.refreshVisibility();
                    }
                }
            }
        }
    }
}

源码中可见，内部定义了ConnectivityReceiver来监听衔接状况的改变，然后内部控制MediaRouteButton的显现。

处理

问题1

App发动时，虽然自动扫描周边Routes，来更新能够Cast Devices状况

    //Init Cast
    public static void initCast(Context context) {
        if (context == null)
            return;
        if (initialized) {
            CastContextManager.getInstance().addRouter(context);
            return;
        }
        initialized = true;
        //初始化CastContextManager
        ....
    }
    public void addRouter(Context context) {
        if(castContext !=null){
            MediaRouter mediaRouter = MediaRouter.getInstance(context);
            mediaRouter.removeCallback(callback);
            mediaRouter.addCallback(MediaRouteSelector.EMPTY, callback, MediaRouter.CALLBACK_FLAG_PERFORM_ACTIVE_SCAN);
        }
    }
    private final MediaRouter.Callback callback = new MediaRouter.Callback() {
        @Override
        public void onProviderAdded(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderAdded(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderAdded  " + provider.getRoutes());
        }
        @Override
        public void onProviderRemoved(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderRemoved(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderRemoved  " + provider.getRoutes());
        }
        @Override
        public void onProviderChanged(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderChanged(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderChanged  " + provider.getRoutes());
        }
    };

问题2

因为无法收到onCastStateChanged的回调，而且MediaRouteButton内部监听了衔接状况的改变来更新显现，那么咱们也效仿相同的完成，通过监听当时衔接状况，结合MediaRouteButton的可见性，来判别Available Cast Devices

当时衔接断开，直接躲藏MediaRouteButton
当时衔接康复，查询是否有Available Cast Devices，来设置MediaRouteButton可见
再判别MediaRouteButton是否可见，来设置新视图的可见性

    public static boolean checkCastDevice(Context activity) {
        //如果当时无衔接， 阐明unavailable Cast devices
        if (!NetworkMonitor.isConnected(App.applicationContext())) return false;
        MediaRouter mediaRouter = MediaRouter.getInstance(activity);
        List<MediaRouter.RouteInfo> routes = mediaRouter.getRoutes();
        if (routes != null && routes.size() != 0) {
            for (MediaRouter.RouteInfo info : routes) {
                if (info.getDeviceType() != MediaRouter.RouteInfo.CONNECTION_STATE_DISCONNECTED
                        && !info.isDefault() && !info.isBluetooth() && !info.isDeviceSpeaker()) {
                    return true;
                }
            }
        }
        return false;
    }
    private NetworkMonitor.OnNetworkListener onNetWorkListener = (last, current) -> {
        showMediaRouteButton(CastHelper.checkCastDevice(getActivity()));
        //check MediaRouteButton isVisible
        ...
    };

总结

部分设备当非杀进程从头发动App，不能自动扫描routes，需求在添加自动扫描，来获取最新的Cast Devices

部分设备无法获取onCastStateChanged回调，且MediaRouteButton内部会监听衔接状况设置显隐性，所以咱们也同样监听衔接状况的改变，来判别Cast 是否可用

Android 集成 Google Cast 异常问题

GoogleCast 异常问题

需求

Fragment/Activity 发动时查询Available Cast Devices，暂命名办法1

Fragment/Activity 处于前台时，动态获取Availabe Cast Devices， 暂命名办法2

问题

分析

处理

问题1

问题2

总结

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作者信息

Fragment/Activity 发动时查询Available Cast Devices，`暂命名办法1`

Fragment/Activity 处于前台时，动态获取Availabe Cast Devices， `暂命名办法2`