反思:如何使用参数调用方法 [英] Reflection: How to Invoke Method with parameters

问题描述

我试图通过带参数的反射调用一个方法，我得到:

I am trying to invoke a method via reflection with parameters and I get:

对象与目标类型不匹配

如果我调用一个没有参数的方法，它工作正常.如果我调用方法 Test("TestNoParameters")，基于以下代码，它工作正常.但是，如果我调用 Test("Run")，则会出现异常.我的代码有问题吗?

If I invoke a method without parameters, it works fine. Based on the following code if I call the method Test("TestNoParameters"), it works fine. However if I call Test("Run"), I get an exception. Is something wrong with my code?

我最初的目的是传递一个对象数组，例如public void Run(object[] options) 但这不起作用，我尝试了一些更简单的方法，例如字符串没有成功.

My initial purpose was to pass an array of objects e.g. public void Run(object[] options) but this did not work and I tried something simpler e.g. string without success.

// Assembly1.dll
namespace TestAssembly
{
    public class Main
    {
        public void Run(string parameters)
        { 
            // Do something... 
        }
        public void TestNoParameters()
        {
            // Do something... 
        }
    }
}

// Executing Assembly.exe
public class TestReflection
{
    public void Test(string methodName)
    {
        Assembly assembly = Assembly.LoadFile("...Assembly1.dll");
        Type type = assembly.GetType("TestAssembly.Main");

        if (type != null)
        {
            MethodInfo methodInfo = type.GetMethod(methodName);

            if (methodInfo != null)
            {
                object result = null;
                ParameterInfo[] parameters = methodInfo.GetParameters();
                object classInstance = Activator.CreateInstance(type, null);

                if (parameters.Length == 0)
                {
                    // This works fine
                    result = methodInfo.Invoke(classInstance, null);
                }
                else
                {
                    object[] parametersArray = new object[] { "Hello" };

                    // The invoke does NOT work;
                    // it throws "Object does not match target type"             
                    result = methodInfo.Invoke(methodInfo, parametersArray);
                }
            }
        }
    }
}

推荐答案

把methodInfo"改成classInstance"，就像用空参数数组调用一样.

Change "methodInfo" to "classInstance", just like in the call with the null parameter array.

  result = methodInfo.Invoke(classInstance, parametersArray);

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