C++编写api一例

 

C++编写api一例
; Com.Xp.VCT.def文件
;------------------------------
; Com.Xp.VCT.def : 定义模块参数。
LIBRARY      "Com.Xp.VCT"
EXPORTS
	;VCT相关操作方法
	OpenVCT @1
	GetFileHandle @2
	ReSetVCT @3
	ReadNextLine @4
	CloseVCT @5
	Test @6
	Input_Output @7

//Com.Xp.VCT.cpp 文件
#include "stdafx.h"
#include "resource.h"
#include "dllmain.h"
#include "VCT.h"
#include "IO.h"
#include "stdio.h"
#include <fcntl.h>
#include <stdlib.h>
#include <share.h>
//-------------------------------------------
 VCT m_vct;
 STDAPI_(bool) OpenVCT(char* FileName)
 {
	  bool rbc=false;
	  rbc=m_vct.Open(FileName);
      return rbc;//
 };
 STDAPI_(int) GetFileHandle()
 {
      int fh=m_vct.m_FileHandle;
	  return fh;
 }
 STDAPI_(bool) ReSetVCT()
 {
	  bool rbc=false;
	  rbc=m_vct.ReSet();
      return rbc;//
 };
 STDAPI_(char *) ReadNextLine()
 {
	 char* tt;
	 tt=m_vct.ReadNextLine();
	 return tt;//
 };
 STDAPI_(bool) CloseVCT()
 {
	 bool rbc=false;
	 rbc=m_vct.Close();
     return rbc;//
 };
 STDAPI_(char*) Test()
 {
     char* tt="hello world test";
	 return tt;
 };
 STDAPI_(char*) Input_Output(char* msg)
 {
	 char* tt=msg;
	 
	  int fh1 = _open(msg, _O_RDONLY ); 
	  //if(_sopen_s(&this->m_FileHandle,FileName,_O_RDONLY, _SH_DENYNO, 0))
	  if( fh1 != -1 )
	  {
          tt="opened file!";
		  _close( fh1 );
	  }
	  else
	  {
          tt="no open file";
	  }
     return tt;
 }

//VCT.h文件
//-------------------------------------
/******************************************
  功能：定义VCT头文件的读取方法的类VCT.h
  vp：hsg
  create date：2009-07-15
*******************************************/
class VCT
{
public:
	VCT(void);
	~VCT(void);
	//打开VCT文件
	bool Open(char* FileName);
	//重新设置指针到首地址
	bool ReSet();
	//读取下一行字符串
	char* ReadNextLine();
	char* ReadNextLine_1();
	//查询
	//bool Seek();
	//关闭VCT文件
	bool Close();

	//属性
	char* m_ErrorMessage;
	int m_FileHandle;
};
//VCT.cpp文件
//-------------------------------------
#include "StdAfx.h"
#include <string>
#include <fcntl.h>
#include <stdlib.h>
#include <share.h>
#include "VCT.h"
#include "io.h"
#include "stdio.h"

VCT::VCT(void)
{
}
VCT::~VCT(void)
{
}
//打开VCT文件
bool VCT::Open(char* FileName)
{
   bool rbc=false;
   
  int fh1;
  fh1 = _open(FileName, _O_RDONLY ); 
  //if(_sopen_s(&this->m_FileHandle,FileName,_O_RDONLY, _SH_DENYNO, 0))
  if( fh1 != -1 )
  {
     //this->m_FileHandle=open(FileName,1);
     m_FileHandle =fh1;
     rbc=true;
  }
  else
  {
     rbc=false;
  }
   
   return rbc;
};
bool VCT::ReSet(){
	return false;
};
//读取下一行字符串
char* VCT::ReadNextLine()
{
	int fh=m_FileHandle;
	char* ret="";
	char* tt="";
	char buffer[1];
	unsigned int nbytes = 1, bytesread;
	if(!_eof(fh))
	{
	   //getline(
       bytesread=_read(fh,buffer,nbytes);
	   if(bytesread>0)
	   {
          tt=buffer;//new char[0];
	   }
	   else
	   {
          tt="";
	   }
	}
    return tt;
};
//读取下一行字符串
char* VCT::ReadNextLine_1()
{
	int fh=m_FileHandle;
	char* ret;
	char* tt;
	char buffer[1000];
	unsigned int nbytes = 1000, bytesread;
	if(!_eof(fh))
	{
       bytesread=_read(fh,buffer,nbytes);
       tt=buffer;//new char[0];
	}
    return tt;
};
//close
//关闭VCT文件
bool VCT::Close()
{
	bool rbc=false;
   	if(m_FileHandle>0)
	{
       _close(m_FileHandle);
	   rbc=true;
	}
	return rbc;
};
.Net C#  测试代码
public class Com_Xp_VCT_API
{
        //-------------X.dll----------------------
        public const string XDLL = "Com.Xp.VCT.dll";
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "OpenVCT")]
        public static extern bool OpenVCT(string FileName);
        //GetFileHandle
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "GetFileHandle")]
        public static extern long GetFileHandle();
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "ReadNextLine")]
        public static extern string ReadNextLine();
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "CloseVCT")]
        public static extern bool CloseVCT();
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "ReSetVCT")]
        public static extern bool ReSetVCT();
        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "Test")]
        public static extern string Test();

        [DllImport(XDLL, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, EntryPoint = "Input_Output")]
        public static extern string Input_Output(string msg);
}
private void button2_Click(object sender, EventArgs e)
{
            string tt = Com_Xp_VCT_API.Test();
            MessageBox.Show(tt.ToString(), "读取值Test");
            tt = Com_Xp_VCT_API.Input_Output(Application.StartupPath+"//tt.txt");
            MessageBox.Show(tt.ToString(), "读取值Input_Output");
            bool rbc = Com_Xp_VCT_API.OpenVCT(Application.StartupPath + "//tt.txt");
            MessageBox.Show(rbc.ToString(), "读取值OpenVCT");
            long fh=Com_Xp_VCT_API.GetFileHandle();
            MessageBox.Show(fh.ToString(), "读取值GetFileHandle");
            string line = Com_Xp_VCT_API.ReadNextLine();
            while (line != "")
            {
                this.textBox3.AppendText(line);
                line = Com_Xp_VCT_API.ReadNextLine();
            }
            //MessageBox.Show(line, "读取值ReadNextLine");
            Com_Xp_VCT_API.CloseVCT();
}