xamarin.forms - Xamarin Plugin.Permission。请求权限时出错

问题描述

我正在尝试使用Plugin.Permissions和 Xamarin.Forms授予我的 android 应用程序的权限

我正在关注提供的示例，但出现以下错误：

04-10 17:42:09.234 I/MonoDroid(15633): UNHANDLED EXCEPTION:
04-10 17:42:09.234 I/MonoDroid(15633): System.MissingMethodException: Method not found: Android.App.Activity Xamarin.Essentials.Platform.get_CurrentActivity()
04-10 17:42:09.234 I/MonoDroid(15633):   at TestApp.Views.MainPage.OnButtonClicked (System.Object sender, System.EventArgs e) [0x000c3] in C:\projects\my\android-projects\TestXamarin\TestXamarinProject\TestApp\TestApp\Views\MainPage.xaml.cs:31 
04-10 17:42:09.234 I/MonoDroid(15633):   at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2019-10/android/release/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1021 
04-10 17:42:09.234 I/MonoDroid(15633):   at Android.App.SyncContext+<>c__DisplayClass2_0.<Post>b__0 () [0x00000] in <4ccdb3137d974856b786e1aeebbfbab6>:0 
04-10 17:42:09.234 I/MonoDroid(15633):   at Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in <4ccdb3137d974856b786e1aeebbfbab6>:0 
04-10 17:42:09.235 I/MonoDroid(15633):   at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00009] in <4ccdb3137d974856b786e1aeebbfbab6>:0 
04-10 17:42:09.235 I/MonoDroid(15633):   at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.44(intptr,intptr)

这是我的主要活动：

using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.OS;
using Plugin.Permissions;

namespace ExoPlayerVU.Droid
{
    [Activity(Label = "TestApp", Icon = "@mipmap/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(savedInstanceState);

            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
            LoadApplication(new App());
        }

        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
        {
            Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
            PermissionsImplementation.Current.OnRequestPermissionsResult(requestCode, permissions, grantResults);

            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}

我正在从 MainPage.xaml.cs 请求单击按钮的权限：

public async void OnButtonClicked(object sender, EventArgs e)
{
    var status = await CrossPermissions.Current.CheckPermissionStatusAsync<StoragePermission>();
    if (status != PermissionStatus.Granted)
    {
        // The error occurs here 
        if (await CrossPermissions.Current.ShouldShowRequestPermissionRationaleAsync(Permission.Storage))
        {
            await DisplayAlert("Access needed", "This application uses storage", "OK");
        }

        status = await CrossPermissions.Current.RequestPermissionAsync<StoragePermission>();
    }

    if (status == PermissionStatus.Granted)
    {
        // my logic
    }
    else
    {
        await DisplayAlert("Storage access denied", "Can not continue, try again.", "OK");
    }
}

Plugin.Permissions 和 Xamarin.Essentials 版本是最新的。我做错了什么？

提前致谢

更新 AndroidManifest.xml：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.companyname.testapp" android:installLocation="auto">
    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
    <application android:label="TestApp.Android"></application>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
    <uses-permission android:name="android.permission.READ_PROFILE" />
    <uses-permission android:name="android.permission.WRITE_PROFILE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>

更新 2

我也有应用程序类：

[Application]
public class DemoApplication : Application
{
    // ...

    public PlayerApplication(IntPtr javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)
    {
    }

    public PlayerApplication()
    {
    }

    public override void OnCreate()
    {
        base.OnCreate();
        userAgent = Util.GetUserAgent(this, "TestApp");
        // Tried to initialize here, but also doesn't work
        //CrossCurrentActivity.Current.Init(this);
        //Xamarin.Essentials.Platform.Init(this);
    }

    // ...
}

Xamarin 版本：16.5

Xamarin.Android SDK：10.2

核桃：

Xamarin.Forms：4.4

Xamarin.Essentials：1.5.2

标签： xamarin.formsandroid-permissionsxamarin.essentials

xamarin.forms - Xamarin Plugin.Permission。请求权限时出错

问题描述

解决方案

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