c#.net下成功调用c++编写的标准dll

研究了差不多有两天的样子，才在今天上午把问题解决，虽然其中有过多的烦躁，但是风雨过后的感觉还是让人振奋的。

好了，闲话不说，记录下来解决方案

这是同事编写的c++标准dll.

==========================

#include "query_agent.h"
#include "stdio.h"
//#include "afxinet.h"

LIBEXPORT_API int __stdcall query(char* userAccount, char* startDate, char* endDate)
{
printf("Query user /"%s/"/'s information from %s to %s!/n",/
userAccount, startDate, endDate);
//CInternetSession connection;
//CFtpConnection *pFtpConnection;
//pFtpConnection = connection.GetFtpConnection("139.24.254.9","cn1xx140","hahaha",TRUE);

return 0;
}

=============================

接下来就是.net平台下的事了

封装dll.

=============================

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Runtime.InteropServices;

/// <summary>
/// Summary description for DllMethods
/// </summary>
public class DllMethods
{
public DllMethods()
{
//
// TODO: Add constructor logic here
//
}

[DllImport("CPPDll.dll")]
public static extern int query(ref string userAccount, ref string startDate, ref string endDate);
}
=================================

页面上的调用

================================

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
string user = "00";
string query = "11";
string result = "22";
int i = DllMethods.query(ref user, ref query, ref result);
Label1.Text = i.ToString();
}
}
===================================

运行成功！

notes:需要把dll拷贝到系统的system32目录下，否则报错。

希望对有相同疑惑的朋友有帮助^-^