android - LocationClient 在 `onDisconnect` 处自动重新连接

Question

当连接丢失时(当用户清除 RAM 时)，我尝试重新连接到 LocationClient。

我尝试使用这段代码:

private final GooglePlayServicesClient.ConnectionCallbacks mConnectionCallback = new GooglePlayServicesClient.ConnectionCallbacks() {

    @Override
    public void onDisconnected() {
        mLocationClient.removeLocationUpdates(mLocationListener);
        mLocationClient.disconnect();
        mLocationClient= null;

        mLocationClient= new LocationClient(mContext, mConnectionCallback, mConnectionFailedCallback);
        mLocationClient.connect(); // NULL POINTER EXCEPTION
    }

    @Override
    public void onConnected(Bundle bundle) {
          ...
    }
};

但是我在 mLocaitonClient.connect() 中得到了 NullPointerException。

10-15 08:33:26.478: E/AndroidRuntime(19572): FATAL EXCEPTION: main
10-15 08:33:26.478: E/AndroidRuntime(19572): java.lang.NullPointerException
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.bh.a(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.k.f(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.k$e.onServiceConnected(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.l.a(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.k.connect(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.location.LocationClient.connect(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.myapp.MyLocationClient$1.onDisconnected(MyLocationClient.java:92)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.k.A(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.k$e.onServiceDisconnected(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.google.android.gms.internal.l$a$a.onServiceDisconnected(Unknown Source)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1102)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1116)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.os.Handler.handleCallback(Handler.java:615)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.os.Handler.dispatchMessage(Handler.java:92)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.os.Looper.loop(Looper.java:137)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at android.app.ActivityThread.main(ActivityThread.java:4898)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at java.lang.reflect.Method.invokeNative(Native Method)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at java.lang.reflect.Method.invoke(Method.java:511)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
10-15 08:33:26.478: E/AndroidRuntime(19572):    at dalvik.system.NativeStart.main(Native Method)

如何修复它并重新连接？

Answer 1

一个更简单的解决方案是在 OnDisconnect 中什么也不做。

public void onDisconnect(){
     //do nothing to client
}

需要使用客户端时只需检查是否已连接

if(mLocationClient.isconnected()){
     mLocationClient.connect();
}

Google Play 服务似乎可以很好地重新连接，无需大惊小怪。

我已经在 4.0.4 和 4.2.2 上成功地使用了它。