Question

我尝试在连接丢失时重新连接到LocationClient（当用户清除RAM时）。

我尝试使用此代码：

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) {
          ...
    }
};

但我在mLocaitonClient.connect()内得到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)

如何修复并重新连接？

Answer 1

更简单的解决方案是在OnDisconnect中无所作为。

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

当需要使用客户端时，只需检查是否已连接

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

Google Play服务似乎可以轻松重新连接。

我已成功使用4.0.4和4.2.2。

Answer 2

我找到了解决方案！只需使用Handler。

@Override
public void onDisconnected() {

    new Handler().post(new Runnable() {
        @Override
        public void run() {
            mLocationClient.removeLocationUpdates(mLocationListener);
            mLocationClient.disconnect();
            mLocationClient = null;

            mLocationClient = new LocationClient(mContext, mConnectionCallback, mConnectionFailedCallback);
            mLocationClient.connect(); // NOW WORKING
        }
    }
}

Answer 3

在官方文档（http://developer.android.com/reference/com/google/android/gms/location/LocationClient.html）中，写道：

public void disconnect ()

“关闭与Google Play服务的连接。调用此方法后，无法对此对象进行调用。”

因此，您之后无法调用connect()，您必须像第一次重新创建LocationClient对象才能再次连接。

LocationClient自动重新连接`onDisconnect`

3 个答案: