Action委托。如何获得调用方法的实例

本文介绍了Action委托。如何获得调用方法的实例的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个动作，我不知道我怎么能访问调用方法的实例

I have an Action and I wonder how could I access the instance that call the method.

例：

this.FindInstance(() => this.InstanceOfAClass.Method()); this.FindInstance(() => this.InstanceOfAClass2.Method()); this.FindInstance(() => this.InstanceOfAClass3.Method()); public void FindInstance(Action action) { // The action is this.InstanceOfAClass.Method(); and I want to get the "Instance" // from "action" }

获得了实例 //

感谢您

Thank you

推荐答案

我认为你正在寻找的的 Delegate.Target 属性。

I think you're looking for the Delegate.Target property.

编辑：好的，现在我看到你以后，你需要代表动作表达式树。然后，你可以找到方法调用另一个表达式树的目标，搭建起一个LambdaExpression，编译并执行它，并查看结果：

Okay, now I see what you're after, and you need an expression tree representing the action. Then you can find the target of the method call as another expression tree, build a LambdaExpression from that, compile and execute it, and see the result:

using System; using System.Linq.Expressions; class Test { static string someValue; static void Main() { someValue = "target value"; DisplayCallTarget(() => someValue.Replace("x", "y")); } static void DisplayCallTarget(Expression<Action> action) { // TODO: *Lots* of validation MethodCallExpression call = (MethodCallExpression) action.Body; LambdaExpression targetOnly = Expression.Lambda(call.Object, null); Delegate compiled = targetOnly.Compile(); object result = compiled.DynamicInvoke(null); Console.WriteLine(result); } }

请注意，这是令人难以置信的脆弱 - 但它应该工作在简单的情况下。

Note that this is incredibly brittle - but it should work in simple cases.