托管dll动态加载

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

namespace WebService1
{
    /// <summary>
    /// DllInvoke 的摘要说明
    /// </summary>
    public class DllInvoke
    {
        [DllImport("kernel32.dll")]
        private extern static IntPtr LoadLibrary(string path);

        [DllImport("kernel32.dll")]
        private extern static IntPtr GetProcAddress(IntPtr lib, string funcName);

        [DllImport("kernel32.dll")]
        private extern static bool FreeLibrary(IntPtr lib);
      

        private IntPtr hLib;       
        public DllInvoke(String DLLPath)
        {
            hLib = LoadLibrary(DLLPath);
        }

        ~DllInvoke()
        {
            FreeLibrary(hLib);           
        }

        //将要执行的函数转换为委托
        public Delegate Invoke (string APIName,Type t) 
        {
            IntPtr api = GetProcAddress(hLib, APIName);
            return (Delegate)Marshal.GetDelegateForFunctionPointer(api, t);
        }

    }
}

上面类的主要作用是通过api动态找到要加载的托管dll函数，返回函数的代理（指针），C++里面好像也可以这么加载，下次在c++中实验下

下面代码是调用：

public class Test
{
 public delegate int SetDBConfig(string IpAddress, string DBname, string UserName, string psw);//通过委托来声明方法

 DllInvoke dll;
        SetDBConfig setDBConfig;

 public Test
 {
     dll = new DllInvoke(Server.MapPath(@"~/bin/dllagain.dll")); //实例化dll
            setDBConfig = (SetDBConfig)dll.Invoke("SetDBConfig", typeof(SetDBConfig));           
 }

 public static void Main()
 {
            setDBConfig(string IpAddress, string DBname, string UserName, string psw);//此处进行调用
 }
}

转自：http://zhouweigang01.blog.163.com/blog/static/934090720095492458949/