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.csdn.net/u/20110126/17/40811C5F-A561-47F9-AEB0-43C9A893F35B.html

http://blog.csdn.net/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msDWORD 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) #endifCWininetAsync::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 Flagif(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 functionif(::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 Contextif(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 contextif(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200if(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-8if(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 handlecase 0:wa->hConnect = (HINTERNET)pRes->dwResult;MyODS("Connect handle created");::SetEvent(wa->hConnectedEvent);break;//Request handlecase 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