C#如何使用Reflect获取dll文件中的类型并调用？

System.Reflection;

static void Main(string[] args)
        {
            //dll文件路径
            string path = @"D:\VS2015Project\001\Computer\bin\Debug\computer.dll";

            //加载dll文件
            Assembly asm = Assembly.LoadFile(path);

            //获取类
            Type type = asm.GetType("Computer.Computer");

            //创建该类型的实例
            object obj = Activator.CreateInstance(type);

            //获取该类的方法
            MethodInfo mf = type.GetMethod("ShowDrives");

            //调用方法
            mf.Invoke(obj, null);

            Console.ReadKey();
        }

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Computer
{
    public class Computer
    {
        private DriveInfo[] drives;
        public Computer()
        {
            this.drives = DriveInfo.GetDrives();
        }
        public void ShowDrives()
        {
            Console.WriteLine("该电脑的磁盘驱动器有：\r\n");
            foreach (var item in drives)
            {
                Console.WriteLine(item);
            }
        }
    }
}