Plugin.Geolocator 退出方法(死锁?)

Plugin.Geolocator exits method (deadlock?)

我正在构建一个 Xamarin 应用程序,对于地理定位,我正在使用 GeolocatorPlugin

问题是一旦代码想要获取位置,代码就存在而没有警告。

我的 class 字段:

private Position position;
private IGeolocator locator = CrossGeolocator.Current;

我的页面构造函数:

public MainPage()
{
    InitializeComponent();

    locator.PositionChanged += Locator_PositionChanged;
    locator.PositionError += Locator_PositionError;
}

OnAppearing 事件正在调用 getLocationPermission:

    private async Task GetLocationPermission()
    {
        var status = await CrossPermissions.Current.CheckPermissionStatusAsync(Permission.LocationWhenInUse);
        if (status != PermissionStatus.Granted)
        {
            //Not granted, request permission
            if (await CrossPermissions.Current.ShouldShowRequestPermissionRationaleAsync(Permission.LocationWhenInUse))
            {
                // This is not the actual permission request
                await DisplayAlert("Need your permission", "We need to access your location", "Ok");
            }

            // This is the actual permission request
            var results = await CrossPermissions.Current.RequestPermissionsAsync(Permission.LocationWhenInUse);
            if (results.ContainsKey(Permission.LocationWhenInUse))
                status = results[Permission.LocationWhenInUse];
        }
        //Already granted, go on
        if (status == PermissionStatus.Granted)
        {
            //Granted, get the location
            GetLocation();
            await GetVenues();
            await locator.StartListeningAsync(TimeSpan.FromMinutes(30), 500);
        }
        else
        {
            await DisplayAlert("Access to location denied", "We don't have access to your location.", "OK");
        }
    }

权限被授予并获取到GetLocation()方法:

    private async void GetLocation()
    {
        //var locator = CrossGeolocator.Current;
        try
        {
            var myPosition = await locator.GetPositionAsync();
            position = new Position(myPosition.Latitude, myPosition.Longitude);
        }
        catch (Exception ex)
        {
            throw;
        }
        if (position == null)
        {
            //Handle exception
        }
    }

一旦使用 locator.GetPositionAsync() 到达该行,它就会停止。不会抛出异常,也不会引发 PositionError。

不知道为什么,一开始用了一次,之后就没用了。

de Android模拟器中的location设置如下:

根据我的研究,您没有像 this link

那样 Location Changes

我写了一个关于 Location changes 的演示。这是 运行 屏幕截图。

这是我的演示 https://github.com/851265601/GeolocationDemo