android - Google Play 服务位置在恢复时停止位置更新，无需调用 onDisconnected

Question

我有一个带有 Google map 的 Android 应用，并通过 Google Play 服务的新位置 API 自动更新位置。

实现方式如下: https://developer.android.com/training/location/receive-location-updates.html

我专门尝试接收 GPS/准确位置。

它工作 100% 完美且正常，GPS 图标位于上方，每隔几秒就会出现位置信息，不用担心。

奇怪的问题似乎是，如果您切换到 Google map ，稍等一下，然后切换回我的应用程序，我的应用程序就会再获得一次位置更新，然后停止接收更新。

我的应用程序在 Pause/onStop 上正确停止位置更新，并在 Start/onResume 上重新连接并重新启动它们。

从 Google map 切换回来后，我的调试 Toast 显示“已连接”，并再显示一个“更新位置”，然后更新停止。 onDisconnected() 没有被调用，并且检查 mLocationClient.isConnected() 报告“true”。

此后，我添加了一个黑客解决方法，其中的计时器处理程序每​​隔几秒运行一次，如果在过去 10 秒内未找到位置，它会调用下面的 stopPauseLocation() 和 checkStartLocation()，这确实修复了问题和地点又开始出现。显然这是一个丑陋的黑客行为，我对此并不满意。

这似乎是一个错误，Google map 和我自己的应用程序之间存在冲突，但是，我一生都无法找到真正的解决方案。

有什么想法吗？

以下是关键代码 fragment :

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Create the LocationRequest object
    mLocationRequest = LocationRequest.create();
    // Use high accuracy
    mLocationRequest.setPriority(
            LocationRequest.PRIORITY_HIGH_ACCURACY);
    // Set the update interval to 2 seconds
    mLocationRequest.setInterval(2000);
    // Set the fastest update interval to 1 second
    mLocationRequest.setFastestInterval(1000);
    /*
     * Create a new location client, using the enclosing class to
     * handle callbacks.
     */
    mLocationClient = new LocationClient(this, this, this);

    mLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
}

@Override
protected void onStart() {
    super.onStart();

    // Check our connection to play services
    checkStartLocation();
}

/*
 * Called when the Activity is no longer visible at all.
 * Stop updates and disconnect.
 */
@Override
protected void onStop() {
    stopPauseLocation();
}

/*
 * Called by Location Services when the request to connect the
 * client finishes successfully. At this point, you can
 * request the current location or start periodic updates
 */
@Override
public void onConnected(Bundle dataBundle) {
    // Display the connection status
    Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();
    mLocationClient.requestLocationUpdates(mLocationRequest, this);

    super.onStop();
}

private void stopPauseLocation()
{
    // If the client is connected
    if (mLocationClient.isConnected()) {
        /*
         * Remove location updates for a listener.
         * The current Activity is the listener, so
         * the argument is "this".
         */
        mLocationClient.removeLocationUpdates(this);
    }
    /*
     * After disconnect() is called, the client is
     * considered "dead".
     */
    mLocationClient.disconnect();
}

/**
 * Helper to check if we're connected to play, and try to connect if not
 */
protected void checkStartLocation() {
    if (!mLocationClient.isConnected())
    {
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationClient.connect();
    }
}

/*
 * Called by Location Services when the request to connect the
 * client finishes successfully. At this point, you can
 * request the current location or start periodic updates
 */
@Override
public void onConnected(Bundle dataBundle) {
    // Display the connection status
    Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();
    mLocationClient.requestLocationUpdates(mLocationRequest, this);
}

@Override
public void onDisconnected() {
    // Display the connection status
    Toast.makeText(this, "Disconnected.",Toast.LENGTH_SHORT).show();
}

/*
 * Called by Location Services if the attempt to connect to
 * Location Services fails.
 */
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Toast.makeText(this, "onConnectionFailed", Toast.LENGTH_SHORT).show();
}

 // Define the callback method that receives location updates
@Override
public void onLocationChanged(Location location) {
    // Report to the UI that the location was updated
    String msg = "Updated Location: " +
            Double.toString(location.getLatitude()) + "," +
            Double.toString(location.getLongitude());
    Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
}

Answer 1

我发现的解决这个问题的唯一方法是黑客攻击，但这是我想出的最好的黑客版本。

下面的代码将每 10 秒(然后逐渐增加 15 秒、20 秒、最多 30 秒)检查一次位置更新。如果没有收到位置，它会调用removeLocationUpdates()和requestLocationUpdates()，这似乎解决了我的问题。

private Handler locationCheck = null;
// Track the time of the last location update
private long lastLocationUpdate = System.currentTimeMillis();
private long lastLocationWaitTime = 0;
// How long to wait until we reconnect (10 sec)
private long WAIT_LOCATION_AGE_START = 10000;
// Increments of how much longer to wait before next check
// Increments on every failure to give the system more time to recover
private long WAIT_LOCATION_AGE_INCREMENT = 5000;
// Max time to wait
private long MAX_WAIT_LOCATION_AGE = 30000;

Add to onCreate in your class:
locationCheck = new Handler();

Add to onResume/onStart:
lastLocationUpdate = System.currentTimeMillis();
lastLocationWaitTime = WAIT_LOCATION_AGE_START;
locationCheck.removeCallbacks(locationCheckRunnable);
locationCheck.postDelayed(locationCheckRunnable, 1000);

Add to onStop/onPause:
locationCheck.removeCallbacks(locationCheckRunnable);

private Runnable locationCheckRunnable = new Runnable() {
    @Override
    public void run() {
        if ((System.currentTimeMillis() - lastLocationUpdate) > lastLocationWaitTime)
        {
            // Verify our connection
            checkStartLocation();
            // Reset the timer
            lastLocationUpdate = System.currentTimeMillis();
            // On next check wait a bit longer
            lastLocationWaitTime += WAIT_LOCATION_AGE_INCREMENT;
            lastLocationWaitTime = Math.min(lastLocationWaitTime, MAX_WAIT_LOCATION_AGE);
            // Re-request location updates
            mLocationClient.removeLocationUpdates(MyParentClassName.this);
            mLocationClient.requestLocationUpdates(mLocationRequest, LocationSocialBaseScreen.this);
        }

        locationCheck.postDelayed(this, 1000);
    }
};

@Override
public void onLocationChanged(Location location) {
    lastLocationUpdate = System.currentTimeMillis();
}