使用wininet接口实现访问http服务

利用wininet接口实现访问http服务：

#include "StdAfx.h"#include <WinInet.h>#pragma comment(lib,"wininet.lib")int main(){//第一步，连接12306网站服务器LPCTSTR lpszAgent = L"WinInetGet/0.1";HINTERNET hInternet = InternetOpen( lpszAgent,INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);LPCTSTR lpszServerName = L"kyfw.12306.cn";INTERNET_PORT nServerPort = INTERNET_DEFAULT_HTTPS_PORT; // HTTPS端口443LPCTSTR lpszUserName = NULL; //无登录用户名LPCTSTR lpszPassword = NULL; //无登录密码DWORD dwConnectFlags = 0;DWORD dwConnectContext = 0;HINTERNET hConnect = InternetConnect(hInternet,lpszServerName, nServerPort,lpszUserName, lpszPassword,INTERNET_SERVICE_HTTP,dwConnectFlags, dwConnectContext);if(hConnect == NULL){return false;}//第二步，访问12306网站登录验证码接口LPCTSTR lpszVerb = L"GET";LPCTSTR lpszObjectName = L"/otn/passcodeNew/getPassCodeNew.do?module=login&rand=sjrand";//L"/urchin.js";LPCTSTR lpszVersion = NULL;    // 默认.LPCTSTR lpszReferrer = L"";   // 没有引用页LPCTSTR *lplpszAcceptTypes = NULL; // Accpet所有类型.DWORD dwOpenRequestFlags =  INTERNET_FLAG_IGNORE_REDIRECT_TO_HTTP |INTERNET_FLAG_KEEP_CONNECTION |INTERNET_FLAG_NO_AUTH |INTERNET_FLAG_NO_COOKIES |INTERNET_FLAG_NO_UI | INTERNET_FLAG_SECURE | //设置启用HTTPSINTERNET_FLAG_RELOAD;DWORD dwOpenRequestContext = 0;//初始化RequestHINTERNET hRequest = HttpOpenRequest(hConnect, lpszVerb, lpszObjectName, lpszVersion,lpszReferrer, lplpszAcceptTypes,dwOpenRequestFlags, dwOpenRequestContext);//发送RequestBOOL bResult = HttpSendRequest(hRequest, NULL, 0, NULL, 0);//失败if (!bResult) {fprintf(stderr, "HttpSendRequest failed, error = %d (0x%x)\n",GetLastError(), GetLastError());return -2;}//第三步，获取返回结果//获得HTTP Response Header信息DWORD dwInfoLevel = HTTP_QUERY_RAW_HEADERS_CRLF;DWORD dwInfoBufferLength = 2048;BYTE *pInfoBuffer = (BYTE *)malloc(dwInfoBufferLength+2);while (!HttpQueryInfo(hRequest, dwInfoLevel, pInfoBuffer, &dwInfoBufferLength, NULL)){DWORD dwError = GetLastError();if (dwError == ERROR_INSUFFICIENT_BUFFER){free(pInfoBuffer);pInfoBuffer = (BYTE *)malloc(dwInfoBufferLength + 2);}else{fprintf(stderr, "HttpQueryInfo failed, error = %d (0x%x)\n",GetLastError(), GetLastError());break;}}pInfoBuffer[dwInfoBufferLength] = '\0';pInfoBuffer[dwInfoBufferLength + 1] = '\0';printf("%s", pInfoBuffer); //很奇怪HttpQueryInfo保存的格式是wchar_t 和下面的InternetReadFile不一样free(pInfoBuffer);//获得HTTP Response 的 Body, 这里是png图片二进制数据流DeleteFile(L"verifycode.png");DWORD dwBytesAvailable;while (InternetQueryDataAvailable(hRequest, &dwBytesAvailable, 0, 0)){BYTE *pMessageBody = (BYTE *)malloc(dwBytesAvailable+1);DWORD dwBytesRead;BOOL bResult = InternetReadFile(hRequest, pMessageBody,dwBytesAvailable, &dwBytesRead);if (!bResult){fprintf(stderr, "InternetReadFile failed, error = %d (0x%x)\n",GetLastError(), GetLastError());break;}if (dwBytesRead == 0)break; // End of File.pMessageBody[dwBytesRead] = '\0';printf("%s", pMessageBody); //InternetReadFile读出来的是普通的char. InternetReadFileEx 似乎是有宽字节版本的//MessageBox((LPCTSTR)(char*)pMessageBody);write_file("verifycode.png",(char*)pMessageBody,dwBytesRead);free(pMessageBody);}return 0;}