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 @1GetFileHandle @2ReSetVCT @3ReadNextLine @4CloseVCT @5Test @6Input_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();}