c# - Delegate.CreateDelegate - 方法参数不兼容

Question

给定以下方法的MethodInfo

public class MyEffects
{
  public Task Test(object action, IDispatcher dispatcher)
  {
    return Task.CompletedTask;
  }
}

为什么以下 CreateDelegate 代码会抛出 System.ArgumentException:方法参数不兼容？

Delegate.CreateDelegate(
    type: typeof(Func<object, IDispatcher, Task>),
    method: discoveredEffect.MethodInfo);

这也是如此

Delegate.CreateDelegate(
    type: typeof(Func<object, object, IDispatcher, Task>),
    method: discoveredEffect.MethodInfo);

Answer 1

由于您想要创建委托(delegate)给非静态方法，因此您必须使用 CreateDelegate(Type, Object, MethodInfo) 提供目标过载:

using System;
using System.Threading.Tasks;

public class Program
{
    public static void Main()
    {
        var method = typeof(MyEffects).GetMethod("Test");
        var obj = new MyEffects();
        var del = Delegate.CreateDelegate(typeof(Func<object, IDispatcher, Task>), obj, method);
        Console.WriteLine(del);
    }
}

public class MyEffects
{
  public Task Test(object action, IDispatcher dispatcher)
  {
    return Task.CompletedTask;
  }
}

public interface IDispatcher {} 

返回

System.Func`3[System.Object,IDispatcher,System.Threading.Tasks.Task]