Question

我正在尝试将方法转换为内部（和嵌套）委托类型。问题是因为它是内部的，Delegate.CreateDelegate失败并引发异常。

System.ArgumentException: 无法绑定到目标方法，因为其签名或安全透明度与委托类型的方法不兼容。

以下是我试图完成此任务的相关代码。

// The method to convert to the internal delegate type
private void OnEnterMenuMode(object sender, EventArgs e);

// The internal nested delegate type
public sealed class KeyboardNavigation {
internal delegate bool EnterMenuModeEventHandler(object sender, EventArgs e);

// The code used to create the delegate
object instance; // Owner of OnEnterMenuMode
EventInfo eventInfo; // The internal event
Delegate.CreateDelegate(eventInfo.EventHandlerType, instance,
    ((Action<object,EventArgs>)method).Method);

Answer 1

我设法通过ConstructorInfo和函数IntPtr构建代理来找到解决方案。

object instance; // Owner of OnEnterMenuMode
EventInfo eventInfo; // The internal event
// There is only one constructor for a `Delegate`, so this
// just makes it easier to find without all of the arguments.
ConstructorInfo constructor = eventInfo.EventHandlerType.GetConstructors()[0];
// Delegate constructors take arguments of `(object, IntPtr)`.
// Where `IntPtr` is a pointer to the method.
IntPtr ptr = ((Action<object,EventArgs>)method)
    .Method.MethodHandle.GetFunctionPointer();
return (Delegate) constructor.Invoke(new object[] { instance, ptr });

嵌套内部类型的CreateDelegate

1 个答案: