wininet异步操作类学习总结[2012/07/11 补充]

网上查了很多资料，也看了很多教程，自己写了一个wininet异步操作类...

多线程使用的还可以，也解决了请求拥堵问题。

 

参照文章：

http://topic.youkuaiyun.com/u/20110126/17/40811C5F-A561-47F9-AEB0-43C9A893F35B.html

http://blog.youkuaiyun.com/cpq37/archive/2010/11/18/6019525.aspx

 

 

WininetAsync.h

#pragma once #include "afx.h" #include <WinInet.h> #include "afxmt.h" typedef void (*GetHttpQueryInfo)(HINTERNET hRequest,LPVOID lpParam); class CWininetAsync : public CObject { public: CWininetAsync(void); ~CWininetAsync(void); public: //请求回调函数 static void __stdcall Callback(HINTERNET hInternet, DWORD dwContext, DWORD dwInternetStatus, LPVOID lpStatusInfo, DWORD dwStatusInfoLen); HANDLE hConnectedEvent,hRequestOpenedEvent, hRequestCompleteEvent; HINTERNET hInstance,hConnect,hRequest; UINT hIndex;//HINTERNET句柄标识 DWORD timeOut;//连接请求的超时时间ms DWORD retries;//重试连接请求的次数 DWORD backOff;//两次重试连接请求之间等待的延迟 BOOL bAllDone;//读取响应内容是否结束 bool m_bRequestError;//请求失败标识（例如:超时） int m_httpStatus;//响应的Http状态码 //发送请求 UINT SendRequest(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData, bool convertUIF8); void CloseEvent(); void CloseHINTERNET(); //清空所有应该删除的属性变量值 void RemoveAll(); CString m_strHtml; //发送请求 请求结束,响应之前 自定义HttpQueryInfo使用 UINT SendRequest(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData, bool convertUIF8, GetHttpQueryInfo queryFunction,LPVOID queryParam); //请求阶段 UINT RequestStage(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData); //响应阶段 UINT ResponseStage(bool convertUIF8); ////回调函数线程 //static DWORD WINAPI AsyncCallbackThread(LPVOID lpParameter); ////回调函数线程 句柄, //HANDLE hCallThread; ////回调函数线程 等待事件,函数创建成功事件 //HANDLE hCallEvent; ////回调函数线程ID //DWORD dwCallbackThreadID; };  

 

WininetAsync.cpp

#include "StdAfx.h" #include "WininetAsync.h" #if TRUE #define MyODS(x) OutputDebugString(x);OutputDebugString("/r/n"); #else #define MyODS(x) #endif CWininetAsync::CWininetAsync(void) { hInstance = NULL; hConnect = NULL; hRequest = NULL; hConnectedEvent = NULL; hRequestOpenedEvent = NULL; hRequestCompleteEvent = NULL; m_strHtml.Empty(); timeOut = 15 * 1000; retries = 1; backOff = 500; m_httpStatus = -1; m_bRequestError = false; //hCallThread = NULL; //hCallEvent = NULL; } CWininetAsync::~CWininetAsync(void) { //确保终结回调线程,主对象销毁后,回调函数dwContext会取到野指针 ::InternetSetStatusCallback(hInstance, NULL); RemoveAll(); } //请求阶段 UINT CWininetAsync::RequestStage(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData) { RemoveAll(); bAllDone = FALSE;//响应结束bool标志 hConnectedEvent = ::CreateEvent(NULL,FALSE,FALSE,NULL);//请求连接事件 hRequestOpenedEvent = ::CreateEvent(NULL,FALSE,FALSE,NULL);//请求打开事件 hRequestCompleteEvent = ::CreateEvent(NULL,FALSE,FALSE,NULL);//请求结束事件 //异步打开连接,INTERNET_FLAG_ASYNC标志异步请求,返回会话句柄 hInstance = ::InternetOpen("asynchttp",INTERNET_OPEN_TYPE_PRECONFIG, NULL,NULL, INTERNET_FLAG_ASYNC);//ASYNC Flag if(hInstance == NULL) { MyODS("InternetOpen failed, error " + GetLastError()); return 1; } //设置回调函数，Callback 回调函数指针 //INTERNET_INVALID_STATUS_CALLBACK标识 判断回调函数是否成功 //Setup callback function if(::InternetSetStatusCallback(hInstance,(INTERNET_STATUS_CALLBACK)Callback) == INTERNET_INVALID_STATUS_CALLBACK) { MyODS( "InternetSetStatusCallback failed, error " + GetLastError()); CloseHINTERNET(); return 1; } //hCallEvent = ::CreateEvent(NULL,TRUE,FALSE,NULL); //hCallThread = ::CreateThread(NULL, 0, AsyncCallbackThread, // this, NULL, &dwCallbackThreadID); //WaitForSingleObject(hConnectedEvent, INFINITE);//等待回调函数设置成功事件 //超时设置 ::InternetSetOption(hInstance,INTERNET_OPTION_CONNECT_TIMEOUT, &timeOut,sizeof(timeOut)); ::InternetSetOption(hInstance,INTERNET_OPTION_CONNECT_RETRIES, &retries,sizeof(retries)); ::InternetSetOption(hInstance,INTERNET_OPTION_CONNECT_BACKOFF, &backOff,sizeof(backOff)); //First call that will actually complete asynchronously //though there is no network traffic //用来标识 在回调函数中 连接句柄被创建 hIndex = 0; //创建连接句柄 hConnect = ::InternetConnect(hInstance, lpszServer,INTERNET_DEFAULT_HTTP_PORT, NULL,NULL,INTERNET_SERVICE_HTTP,0, (DWORD_PTR)this);//Connection handle's Context if(hConnect == NULL) { if(GetLastError() != ERROR_IO_PENDING) { MyODS("InternetConnect failed, error " + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } //Wait until we get the connection handle ::WaitForSingleObject(hConnectedEvent,INFINITE); } //Open the request //用来标识 在回调函数中 请求句柄被创建 hIndex = 1; //创建请求句柄 hRequest = ::HttpOpenRequest(hConnect, requestType, lpszUrl, NULL, lpszReferrer.IsEmpty() ? NULL : lpszReferrer, NULL, INTERNET_FLAG_RELOAD|INTERNET_FLAG_NO_CACHE_WRITE, (DWORD_PTR)this);//Request handle's context if(hRequest == NULL) { if(GetLastError() != ERROR_IO_PENDING) { MyODS("HttpOpenRequest failed, error " + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } //Wait until we get the request handle ::WaitForSingleObject(hRequestOpenedEvent,INFINITE); } //添加Http响应头信息 HttpAddRequestHeaders(hRequest,headData,strlen(headData),HTTP_ADDREQ_FLAG_ADD); BOOL bSendResult; //根据变量requestType，判断是Post还是Get请求 if(0 == requestType.CompareNoCase(_T("POST"))) { int postLen; LPTSTR lpsz; if(postData.IsEmpty()) { postLen = 0; lpsz = NULL; } else { postLen = postData.GetLength(); lpsz = (LPTSTR)(LPCTSTR)postData; } //发送Post请求,headData Http头信息，lpsz Post数据 bSendResult = ::HttpSendRequest(hRequest,headData,strlen(headData), lpsz,postLen); } else //发送Get请求 bSendResult= ::HttpSendRequest(hRequest, headData,strlen(headData),NULL,0); if(!bSendResult) { if(GetLastError() != ERROR_IO_PENDING) { MyODS("HttpSendRequest failed, error " + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } ::WaitForSingleObject(hRequestCompleteEvent, INFINITE); } //判断请求是否失败或者超时 if(m_bRequestError) { CloseEvent(); CloseHINTERNET(); return 1; } //使用 HttpQueryInfo 分析头信息 分析返回状态码 DWORD dwStatusCode; DWORD dwStatusSize = sizeof(dwStatusCode); if(FALSE == ::HttpQueryInfo(hRequest, HTTP_QUERY_STATUS_CODE|HTTP_QUERY_FLAG_NUMBER, &dwStatusCode,&dwStatusSize,NULL)) { MyODS("HttpQueryInfo error " + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } m_httpStatus = dwStatusCode; //判断状态码是否是200 if(HTTP_STATUS_OK != dwStatusCode) { MyODS("HttpStatusCode error " + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } return 0; } //响应阶段 UINT CWininetAsync::ResponseStage(bool convertUIF8) { MyODS( "------------------- Read the response -------------------"); char lpReadBuff[1024]; do { //INTERNET_BUFFERS结构，用来读取响应内容 INTERNET_BUFFERS InetBuff; FillMemory(&InetBuff,sizeof(InetBuff),0); InetBuff.dwStructSize = sizeof(InetBuff); InetBuff.lpvBuffer = lpReadBuff; InetBuff.dwBufferLength = sizeof(lpReadBuff)-1; //异步读取响应内容,InternetReadFileEx 和 IRF_ASYNC 不能少 if(!::InternetReadFileEx(hRequest, &InetBuff,IRF_ASYNC,(DWORD_PTR)this)) { if(GetLastError() == ERROR_IO_PENDING) { MyODS("Waiting for InternetReadFileEx to complete"); ::WaitForSingleObject(hRequestCompleteEvent,INFINITE); } else { MyODS("InternetReadFileEx failed, error" + GetLastError()); CloseEvent(); CloseHINTERNET(); return 1; } } lpReadBuff[InetBuff.dwBufferLength] = 0; //是否需要转码UTF-8 if(convertUIF8) { int lpReadBuffLength = strlen(lpReadBuff); int nWCHAR=MultiByteToWideChar(CP_UTF8,0,lpReadBuff,lpReadBuffLength,NULL,0); WCHAR* szUnicode=new WCHAR[nWCHAR+1]; MultiByteToWideChar(CP_UTF8,0,lpReadBuff,lpReadBuffLength,szUnicode,nWCHAR); szUnicode[nWCHAR]='/0'; m_strHtml += szUnicode; m_strHtml += L"/r/n"; delete szUnicode; } else{ m_strHtml += lpReadBuff; } //INTERNET_BUFFERS结构,读取数据为0,代表响应数据已经读完 if(InetBuff.dwBufferLength == 0) bAllDone = TRUE; } while (bAllDone == FALSE); MyODS("------------------- Request Complete ----------------"); //关闭所有事件，防止内存泄露 CloseEvent(); //关闭所有句柄，防止内存泄露 CloseHINTERNET(); return 0; } UINT CWininetAsync::SendRequest(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData, bool convertUIF8) { UINT uiResult = RequestStage(lpszUrl,lpszServer, requestType,lpszReferrer, headData,postData); if(uiResult == 0) return ResponseStage(convertUIF8); else return uiResult; } ////回调函数线程 //DWORD WINAPI CWinietAsync::AsyncCallbackThread(LPVOID lpParameter) //{ // CWinietAsync* wa = (CWinietAsync*)lpParameter; // InternetSetStatusCallback(wa->hInstance,Callback); // SetEvent(wa->hConnectedEvent); // WaitForSingleObject(wa->hCallEvent,INFINITE); // return 0; //} void CWininetAsync::CloseEvent() { if(hRequestCompleteEvent) { ::CloseHandle(hRequestCompleteEvent); hRequestCompleteEvent = NULL; } if(hRequestOpenedEvent) { ::CloseHandle(hRequestOpenedEvent); hRequestOpenedEvent = NULL; } if(hConnectedEvent) { ::CloseHandle(hConnectedEvent); hConnectedEvent = NULL; } } void CWininetAsync::CloseHINTERNET() { if(hRequest) { ::InternetCloseHandle(hRequest); hRequest = NULL; } if(hConnect) { ::InternetCloseHandle(hConnect); hConnect = NULL; } if(hInstance) { //if(hCallThread) //{ // //设置子线程退出事件，通知回调线程退出 // SetEvent(hCallEvent); // //等待回调线程安全退出 // ::WaitForSingleObject(hCallThread, INFINITE); // ::CloseHandle(hCallThread); //} ::InternetSetStatusCallback(hInstance, NULL); ::InternetCloseHandle(hInstance); hInstance = NULL; } } //异步请求，回调函数 void __stdcall CWininetAsync::Callback(HINTERNET hInternet, DWORD dwContext,DWORD dwInternetStatus,LPVOID lpStatusInfo, DWORD dwStatusInfoLen) { switch(dwInternetStatus) { //创建Internet句柄 case INTERNET_STATUS_HANDLE_CREATED: { INTERNET_ASYNC_RESULT* pRes = (INTERNET_ASYNC_RESULT*)lpStatusInfo; CWininetAsync* wa = (CWininetAsync*)dwContext; if(NULL != wa) { switch(wa->hIndex) { //Connection handle case 0: wa->hConnect = (HINTERNET)pRes->dwResult; MyODS("Connect handle created"); ::SetEvent(wa->hConnectedEvent); break; //Request handle case 1: wa->hRequest = (HINTERNET)pRes->dwResult; MyODS("Request handle created"); ::SetEvent(wa->hRequestOpenedEvent); break; } } } break; //请求发送 case INTERNET_STATUS_REQUEST_SENT: { DWORD* lpBytesSent = (DWORD*)lpStatusInfo; MyODS("Bytes Sent: " + *lpBytesSent); } break; //请求结束 case INTERNET_STATUS_REQUEST_COMPLETE: { INTERNET_ASYNC_RESULT* pAsyncRes = (INTERNET_ASYNC_RESULT*)lpStatusInfo; CWininetAsync* wa = (CWininetAsync*)dwContext; if(ERROR_SUCCESS == pAsyncRes->dwError) { if(NULL != wa) { MyODS("Function call finished"); MyODS("dwResult:" + pAsyncRes->dwResult); MyODS("dwError:" + pAsyncRes->dwError); ::SetEvent(wa->hRequestCompleteEvent); } } //12002 是请求超时错误标志 else if(12002 == pAsyncRes->dwError) //超时 { if(NULL != wa) { MyODS("Function call error"); MyODS("dwResult:" + pAsyncRes->dwResult); MyODS("dwError:" + pAsyncRes->dwError); wa->m_strHtml = _T("NULL"); wa->m_bRequestError = true; ::SetEvent(wa->hRequestCompleteEvent); } } else { if(NULL != wa) { MyODS("Function call error"); MyODS("dwResult:" + pAsyncRes->dwResult); MyODS("dwError:" + pAsyncRes->dwError); wa->m_strHtml = _T("ERROR"); wa->m_bRequestError = true; ::SetEvent(wa->hRequestCompleteEvent); } } } break; case INTERNET_STATUS_RECEIVING_RESPONSE: MyODS("Receiving Response"); break; case INTERNET_STATUS_RESPONSE_RECEIVED: { DWORD* dwBytesReceived = (DWORD*)lpStatusInfo; if(*dwBytesReceived == 0) { CWininetAsync* wa = (CWininetAsync*)dwContext; if(NULL != wa) { wa->bAllDone = TRUE; } MyODS("Received " + *dwBytesReceived); } } break; //case INTERNET_STATUS_CONNECTION_CLOSED: // { // CWinietAsync* wa = (CWinietAsync*)dwContext; // if(NULL != wa) // { // ::SetEvent(wa->hCallEvent); // } // } // break; } } //请求结束,响应之前 自定义HttpQueryInfo使用 UINT CWininetAsync::SendRequest(CString lpszUrl, CString lpszServer, CString requestType, CString lpszReferrer, CString headData, CString postData, bool convertUIF8, GetHttpQueryInfo queryFunction,LPVOID queryParam) { UINT uiResult = RequestStage(lpszUrl,lpszServer, requestType,lpszReferrer, headData,postData); if(uiResult == 0) { //自定义HttpQueryInfo使用 queryFunction(hRequest,queryParam); return ResponseStage(convertUIF8); } else return uiResult; } //清空所有应该删除的属性变量值 void CWininetAsync::RemoveAll() { CloseEvent(); CloseHINTERNET(); //清空m_strHtml内容 if(!m_strHtml.IsEmpty()) m_strHtml.Empty(); m_bRequestError = false; } 

 

封装到自定义线程类中的成员变量，不使用使用局部对象，防止局部对象失效后依然传递进回调函数导致野指针

class CThread { public: CThread(void); public: ~CThread(void); public: CWininetAsync* wa; //异步wininet请求类 } CThread::CThread(void) { wa = new CWininetAsync; } CThread::~CThread(void) { if(wa) { delete wa; wa = NULL; } } 

 

调用

 

 

CString web; CString url; web= _T("www.baidu.com"); url= _T("/index.jsp"); CString headData; headData = _T("Accept: image/gif, image/jpeg, image/pjpeg, application/x-ms-application, application/vnd.ms-xpsdocument, application/xaml+xml, application/x-ms-xbap, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*/r/n" "User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; InfoPath.2; .NET CLR 3.5.21022; .NET CLR 3.5.30729; .NET CLR 3.0.30729)/r/n"); int iResult = wa->SendRequest(url,web,_T("GET"), NULL,headData,NULL,false); return wa->m_strHtml;//响应的HTML内容 

 

补充 - 2012/07/11：

异步调用，如何正常终结回调函数

InternetCloseHandle function

http://msdn.microsoft.com/en-us/library/windows/desktop/aa384350(v=vs.85).aspx

It is safe to call InternetCloseHandle in a callback for the handle being closed. If there is a status callback registered for the handle being closed, and the handle was created with a non-NULL context value, an INTERNET_STATUS_HANDLE_CLOSING callback will be made. This indication will be the last callback made from a handle and indicates that the handle is being destroyed.

 以上代码有2个异步句柄，确保 INTERNET_STATUS_HANDLE_CLOSING 被调用2次后，析构该对象