Question

我尝试使用共享代码库中的以下代码获取用户的当前位置。

此项目的来源位于Dropbox link

using System;
using System.Diagnostics;
using Plugin.Geolocator;
using Plugin.Geolocator.Abstractions;

namespace SampleApp
{
    public class LocationManager
    {
        private DateTimeOffset timestamp;

        private double latitude;

        private double longitude;

        IGeolocator locator;

        public LocationManager()
        {
            asyncInitLocation();
        }

        private async void asyncInitLocation()
        {
            try
            {
                locator = CrossGeolocator.Current;
                locator.DesiredAccuracy = 50;

                if (locator.IsGeolocationEnabled)
                {
                    var position = await locator.GetPositionAsync(timeoutMilliseconds: 20000);
                    timestamp = position.Timestamp;
                    latitude = position.Latitude;
                    longitude = position.Longitude;
                }
                else 
                {
                    Debug.WriteLine("Geolocation is disabled!");
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine("Unable to get location, may need to increase timeout: " + ex);
            }
        }

        public DateTimeOffset getTimestamp()
        {
            return this.timestamp;
        }

        public double getLatitude()
        {
            return this.latitude;
        }

        public double getLongitude()
        {
            return this.longitude;
        }

        public void refresh()
        {
            asyncInitLocation();
        }
    }
}

我收到以下错误。谷歌没有帮助我！

Unable to get location, may need to increase timeout: System.NotImplementedException: This functionality is not implemented in the portable version of this assembly.  You should reference the NuGet package from your main application project in order to reference the platform-specific implementation.
  at Plugin.Geolocator.CrossGeolocator.get_Current () <0x52c7bb60 + 0x0003f> in <filename unknown>:0 
  at SampleApp.LocationManager+<asyncInitLocation>c__async0.MoveNext () <0x52c7ae60 + 0x000bf> in <filename unknown>:0

更新： packages.config文件如下所示

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.Bcl" version="1.1.10" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
  <package id="Microsoft.Bcl.Build" version="1.0.21" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
  <package id="Microsoft.Net.Http" version="2.2.29" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
  <package id="modernhttpclient" version="2.4.2" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
  <package id="Newtonsoft.Json" version="8.0.3" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
  <package id="Xam.Plugin.Geolocator" version="3.0.4" targetFramework="portable-net45+win+wp80+MonoTouch10+MonoAndroid10+xamarinmac20+xamarintvos10+xamarinwatchos10+xamarinios10" />
</packages>

现在我收到以下错误消息：

Unable to get location, may need to increase timeout: System.Threading.Tasks.TaskCanceledException: A task was canceled.
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0002d] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:179 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Plugin.Geolocator.GeolocatorImplementation+<GetPositionAsync>d__27.MoveNext () [0x00597] in C:\projects\xamarin-plugins\Geolocator\Geolocator\Geolocator.Plugin.Android\GeolocatorImplementation.cs:175 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00027] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:176 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:357 
  at BugsAndDrugs.LocationManager+<asyncInitLocation>c__async0.MoveNext () [0x000d4] in /Users/myname/Perforce/depot/test_sandbox/Playground/SampleApp/SampleApp/Manager/LocationManager.cs:32

我错过了什么吗？我已经使用nuget将插件添加到项目中。

Answer 1

我遇到了同样的错误，我用clean-solution解决了然后重建解决方案，并确保将依赖关系添加到所有proyects

Answer 2

重新测试您的问题后，我创建了一个新的Shared Project并在Geolocator.Plugin上添加了Android Project。

注意：

插件文档说：

ACCESS_COARSE_LOCATION＆amp; ACCESS_FINE_LOCATION权限是必需，但库会自动为您添加。此外，如果您的用户正在运行Marshmallow，插件将会自动提示他们获取运行时权限。

但我必须在Android上手动添加此权限。

Manifest看起来像：

<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="pt.sushiathome.shared_geolocator">
    <uses-sdk android:minSdkVersion="15" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <application android:label="shared.geolocator">
    </application>
</manifest>

<强> MainActivity：

Button button = FindViewById<Button>(Resource.Id.myButton);

button.Click += async delegate
{
    try
    {
        var locator = CrossGeolocator.Current;
        locator.DesiredAccuracy = 50;

        if (locator.IsGeolocationEnabled)
        {
            var position = await locator.GetPositionAsync(timeoutMilliseconds: 10000);
            position.ToString();
        }
        else
        {
            System.Diagnostics.Debug.WriteLine("Geolocation is disabled!");
        }
    }
    catch (Exception ex)
    {
        System.Diagnostics.Debug.WriteLine("Unable to get location, may need to increase timeout: " + ex);
    }
};

刚刚在position.ToString();放置一个断点，我找到了位置。（在模拟器和真实设备中测试过。）

<强>注2：

尝试在模拟器中打开GPS：

Xamarin Plugin.Geolocator无法正常工作

2 个答案: