Xamarin - 地理定位不起作用......但为什么 [英] Xamarin - Geolocation doesnt work... But why

问题描述

我只是想开发一个小应用程序，这给了我目前的职位.所以我找到了这个插件，我输入到我的代码中.现在，我得到了所有要编译的东西 - 应用程序启动了，但没有警告就结束了.没有崩溃，什么都没有.甚至 Xamarin 也没有出现任何崩溃的迹象.你们能帮我吗?我什么都没试过，我完全没有想法......;)再次感谢！

I am just trying to develope a little app, that gives me my current position. So I found this plugin that I entered to my code. Now, that I got everything to compile - the app starts but then, without warning ends. No crash, no nothing. Even Xamarin doesnt show any sign of crash. Can you guys help me out? I have tried nothing, and Im all out of ideas... ;) thanks again!

protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.Main);

            //Initialize buttons:

            Button StartButton = FindViewById<Button>(Resource.Id.startbutton);
            TextView txtTestGps = FindViewById<TextView>(Resource.Id.GpsTest);

            ShowGpsCoordinates(StartButton, txtTestGps);
        }

        private void ShowGpsCoordinates(Button StartButton, TextView txtTestGps) 
        {
           Task<double> xy = GiveGpsLocation();
           double xyOut = xy.Result; 

            StartButton.Click += (sender, e) =>
            {
                txtTestGps.Text = xyOut.ToString();   
            };
        }

        private async Task<double> GiveGpsLocation()
        {
            double DoubleWithCoordinates = 0.0;

            var locator = CrossGeolocator.Current;
            locator.DesiredAccuracy = 50;

            var position =  await locator.GetPositionAsync(10000);

            // Console.WriteLine("Position Status: {0}", position.Timestamp);
            // Console.WriteLine("Position Latitude: {0}", position.Latitude);
            // Console.WriteLine("Position Longitude: {0}", position.Longitude);

            DoubleWithCoordinates = position.Latitude; 

            return DoubleWithCoordinates;  
        }

    }

推荐答案

由于您没有等待对异步方法的所有调用，因此可能会吞下异常，从而隐藏崩溃的原因.

Since you are not awaiting all calls to async methods, exceptions might be getting swallowed, hiding the cause of the crash.

也许可以尝试以下操作，看看是否可以得到一个可以告诉您一些信息的异常:

Perhaps try the following and see if you can get an exception that tells you something:

protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.Main);

            //Initialize buttons:

            Button StartButton = FindViewById<Button>(Resource.Id.startbutton);
            TextView txtTestGps = FindViewById<TextView>(Resource.Id.GpsTest);

            Task.Run(async () => {
                await ShowGpsCoordinates(StartButton, txtTestGps);
            }
        }

        private async Task ShowGpsCoordinates(Button StartButton, TextView txtTestGps) 
        {
           double xyOut = await GiveGpsLocation();


            StartButton.Click += (sender, e) =>
            {
                txtTestGps.Text = xyOut.ToString();   
            };
        }

        private async Task<double> GiveGpsLocation()
        {
            double DoubleWithCoordinates = 0.0;

            var locator = CrossGeolocator.Current;
            locator.DesiredAccuracy = 50;

            var position =  await locator.GetPositionAsync(10000);

            // Console.WriteLine("Position Status: {0}", position.Timestamp);
            // Console.WriteLine("Position Latitude: {0}", position.Latitude);
            // Console.WriteLine("Position Longitude: {0}", position.Longitude);

            DoubleWithCoordinates = position.Latitude; 

            return DoubleWithCoordinates;  
        }

    }

这篇关于Xamarin - 地理定位不起作用......但为什么的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！