Question

我目前正在学习C＃中的Reflection。我使用后期绑定从类中调用2个方法。第一种方法（SumNumbers）有效。第二种方法（SumArray）抛出一个异常，说＆＃34;参数计数不匹配＆＃34;。有人可以告诉我如何将整数数组传递给这个方法吗？

>>> from itertools import groupby
>>> a, b = [list(g) for _,  g in groupby(d.values(), type)]
>>> dict(Counter(a[0] + b))
{'NTS': 1, 'VAL': 1, 'PRS': 1, 'MRS': 2}

包含2种方法的类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;

namespace ReflectionWithLateBinding
{
    public class Program
    {
        static void Main()
        {
            //load the current executing assembly
            Assembly executingAssembly1 = Assembly.GetExecutingAssembly();

            //load and instantiate the class dynamically at runtime - "Calculator class"
            Type calculatorType1 = executingAssembly1.GetType("ReflectionWithLateBinding.Calculator");


            //Create an instance of the type --"Calculator class"
            object calculatorInstance1 = Activator.CreateInstance(calculatorType1);

            //Get the info of the method to be executed in the class
            MethodInfo sumArrayMethod1 = calculatorType1.GetMethod("SumArray");

            object[] arrayParams1 = new object[4];

            arrayParams1[0] = 5;
            arrayParams1[1] = 8;
            arrayParams1[2] = 2;
            arrayParams1[3] = 1;
            int sum1;
            //Call "SumArray" Method
            sum1 = (int)sumArrayMethod.Invoke(calculatorInstance, arrayParams1);


            Console.WriteLine("Sum = {0}", sum1);

            Console.ReadLine();

        }



    }
}

Answer 1

您没有将整数数组传递给反射方法，而是传递具有4个整数值的对象数组。这将导致反射想要找到具有4个整数参数的方法。相反，您希望将整数数组作为对象数组中的一个值传递。

更改为：

int[] numbers = { 5, 8, 2, 1 };
object[] arrayParams1 = { numbers };

我还想指出你的Sum方法没有正确写入。你只是将0加到input.Length，而不是数组中存在的值。

你想要

sum += input[i];

最后，根据为什么你想要这样做，在C＃中使用dynamic会比使用反射更容易，最终会导致大致相同类型的异常情况（在您正在调用方法的对象。

dynamic calculatorInstance1 = Activator.CreateInstance(calculatorType1);
calculatorInstance1.SumArray(new int[] { 5,8,2,1 });

编辑，完整的工作样本。我唯一做的就是将参数数组更改为上面的代码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;

namespace ReflectionWithLateBinding
{
    public class Program
    {
        static void Main()
        {
            //load the current executing assembly
            Assembly executingAssembly1 = Assembly.GetExecutingAssembly();

            //load and instantiate the class dynamically at runtime - "Calculator class"
            Type calculatorType1 = executingAssembly1.GetType("ReflectionWithLateBinding.Calculator");


            //Create an instance of the type --"Calculator class"
            object calculatorInstance1 = Activator.CreateInstance(calculatorType1);

            //Get the info of the method to be executed in the class
            MethodInfo sumArrayMethod1 = calculatorType1.GetMethod("SumArray");

            int[] numbers = { 5, 8, 2, 1 };
            object[] arrayParams1 = { numbers };

            int sum1;
            //Call "SumArray" Method
            sum1 = (int)sumArrayMethod1.Invoke(calculatorInstance1, arrayParams1);


            Console.WriteLine("Sum = {0}", sum1);

            Console.ReadLine();

        }
    }

    public class Calculator
    {
        public int SumArray(int[] input)
        {
            int sum = 0;
            for (int i = 0; i < input.Length; i++)
            {
                sum += input[i];
            }
            return sum;
        }
    }
}

如何将整数数组传递给方法：Reflection C＃

1 个答案: