是什么导致我的Grid自定义渲染器让Xamarin.Android抛出此异常？

Question

例外是:

System.MissingMethodException
Constructor on type 'MyApp.Droid.MyGridRenderer' not found

自定义渲染器:

using System;
using Android.Content;
using Android.Graphics;
using Android.Text;
using Android.Util;
using MyApp;
using MyApp.Droid;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(Grid), typeof(MyGridRenderer))]
namespace MyApp.Droid
{
    public class MyGridRenderer : ViewRenderer<Grid, Android.Views.View>
    {
        protected MyGridRenderer(Context context) : base(context)
        {
        }
    }
}

我有Visual Studio Community for Mac版本7.3.2

以防万一,这是iOS的自定义渲染器,没有任何构造函数正常工作:

using System;
using CoreGraphics;
using CoreText;
using Foundation;
using MyApp;
using MyApp.iOS;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(Grid), typeof(MyGridRenderer))]
namespace MyApp.iOS
{
    public class MyGridRenderer : ViewRenderer<Grid, UIView>
    {
    }
}

Answer 1

Android自定义渲染器的构造函数的签名在Xamarin表单的最新版本(2.5.0)中更改为要求传递上下文.

您可以在发行说明中看到这一点.

这不是iOS所需要的.

尝试将protected更改为public.