如何從MethodInfo創建一個Action委託？

Question

我想從MethodInfo對象中獲取操作委託。這可能嗎？

謝謝。

Answer 1

使用Delegate.CreateDelegate：

// Static method 
Action action = (Action) Delegate.CreateDelegate(typeof(Action), method); 

// Instance method (on "target") 
Action action = (Action) Delegate.CreateDelegate(typeof(Action), target, method); 

對於Action<T>等，只是到處指定適當的委託類型。

在.NET中的核心，Delegate.CreateDelegate不存在，但MethodInfo.CreateDelegate的作用：

// Static method 
Action action = (Action) method.CreateDelegate(typeof(Action)); 

// Instance method (on "target") 
Action action = (Action) method.CreateDelegate(typeof(Action), target); 

Answer 2

這似乎對約翰的建議基礎上工作過：

public static class GenericDelegateFactory 
{ 
    public static object CreateDelegateByParameter(Type parameterType, object target, MethodInfo method) { 

     var createDelegate = typeof(GenericDelegateFactory).GetMethod("CreateDelegate") 
      .MakeGenericMethod(parameterType); 

     var del = createDelegate.Invoke(null, new object[] { target, method }); 

     return del; 
    } 

    public static Action<TEvent> CreateDelegate<TEvent>(object target, MethodInfo method) 
    { 
     var del = (Action<TEvent>)Delegate.CreateDelegate(typeof(Action<TEvent>), target, method); 

     return del; 
    } 
}