LocationManager.RequestLocationUpdates 需要几分钟才能在我的手机上返回结果

Question

当我的蓝牙设备断开连接时，我尝试获取我的位置，但总是需要很长时间。

[BroadcastReceiver]
[IntentFilter(new[] { BluetoothDevice.ActionAclDisconnected })]
public class BluetoothReceiver : BroadcastReceiver
{
    public async override void OnReceive(Context context, Intent intent)
    {
        Log2("On bluetooth receive");
        Log2("Intent is: " + intent.Action);

        if (BluetoothDevice.ActionAclDisconnected.Equals(intent.Action))
        {
            BluetoothDevice device = (BluetoothDevice)intent.GetParcelableExtra(BluetoothDevice.ExtraDevice);
            string deviceName = device.Name;

            Log2("Device name is: " + deviceName);

            if (device.Name.ToUpper().IndexOf("FOO") != -1)
            {
                Log2("Getting location");
                var loc = await GetLocation();

                if (loc == null || loc.HasValue == false)
                {
                    Log2("Location is null or does not have value");
                    return;
                }

                Log2("Location is: " + JsonConvert.SerializeObject(loc.Value));
            }
        }
    }
}

static Location latestLocation = null;

private async static Task<(double lat, double lon)?> GetLocation()
{
    LocationManager locationManager = (LocationManager)_this.GetSystemService(LocationService);

    string provider = LocationManager.NetworkProvider;

    if (locationManager.IsProviderEnabled(provider) == false)
    {
        Log2("Provider: " + provider + " was not available");
        provider = LocationManager.GpsProvider;

        if (locationManager.IsProviderEnabled(provider) == false)
        {
            Log2("Provider: " + provider + " was not available");
            provider = locationManager.GetBestProvider(new Criteria(), true);

            if (provider == null)
            {
                Log2("Best provider was not available, returning");
                return null;
            }
        }
    }

    Log2("Requested location update and waiting");
    latestLocation = null;

    locationManager.RequestLocationUpdates(provider, 30000, 1, _this);

    Stopwatch sw = new Stopwatch();

    sw.Start();

    while (latestLocation == null && sw.ElapsedMilliseconds < 30000)
        await Task.Delay(100);

    if (latestLocation == null)
    {
        Log2("Latest location was null, returning");
        return null;
    }

    double latitude = latestLocation.Latitude;
    double longitude = latestLocation.Longitude;

    return (latitude, longitude);
}

public void OnLocationChanged(Location location)
{
    Log2("location changed event.");

    latestLocation = location;
    
    Log2($"Latitude: {location.Latitude}, Longitude: {location.Longitude}");
}

当我检查日志时。 OnLocationChanged 需要超过 8 分钟才能触发。它使用 NetworkProvider，但我也使用 GPS 提供商对其进行了测试。 当我把车停在家里并且我的手机与汽车的蓝牙断开连接时，它就出现了这个问题。在家用蓝牙耳机测试时似乎没有这个问题。 这是日志文件：

[2/21/2024 5:24 PM 22674ms] On bluetooth receive
[2/21/2024 5:24 PM 0019ms] Intent is: android.bluetooth.device.action.ACL_DISCONNECTED
[2/21/2024 5:24 PM 0026ms] Device name is: FOO
[2/21/2024 5:24 PM 0021ms] Getting location
[2/21/2024 5:24 PM 0034ms] Requested location update and waiting
[2/21/2024 5:25 PM 42009ms] Latest location was null, returning
[2/21/2024 5:25 PM 0048ms] Location is null or does not have value
[2/21/2024 5:33 PM 507948ms] location changed event.
[2/21/2024 5:33 PM 0015ms] Latitude: 123.2584486, Longitude: 456.1175657

如何才能在 10 秒内获取位置？

Answer 1

问题是我只将 GPS 权限设置为“使用应用程序时”，而不是一直设置。因此，如果我切换到另一个应用程序或关闭屏幕，它就会无限期地挂起。