使用WinINet和WinHTTP实现Http訪问
飘飘白云 2007-11-30
Http訪问有两种方式,GET和POST,就编程来说GET方式相对简单点,它不用向server提交数据,在这个例程中我使用POST方式,提交数据value1与value2,并从server得到他们的和(value1 + value2)。
为实现Http訪问,微软提供了二套API:WinINet, WinHTTP。WinHTTP比WinINet更加安全和健壮,能够这么觉得WinHTTP是WinINet的升级版本号。这两套API包括了非常多类似的函数与宏定义,呵呵,具体对照请查阅msdn中的文章“Porting WinINet Applications to WinHTTP”,在线MSDN连接:。在这个例程中,通过一个宏的设置来决定是使用WinHttp还是WinINet。代码例如以下:
#define USE_WINHTTP //Comment this line to user wininet.
以下来说说实现Http訪问的流程(两套API都一样的流程):
1, 首先我们打开一个Session获得一个HINTERNET session句柄;
2, 然后我们使用这个session句柄与server连接得到一个HINTERNET connect句柄;
3, 然后我们使用这个connect句柄来打开Http 请求得到一个HINTERNET request句柄;
4, 这时我们就能够使用这个request句柄来发送数据与读取从server返回的数据;
5, 最后依次关闭request,connect,session句柄。
在这个例程中以上各个流程都进行了简单封装,以便对照两套API函数的些许差异。以下让源码说话,原project是一个windows控制台project,你能够非常easy通过拷贝代码重建project。
另:假设你从server得到的返回数据是utf8格式的文本数据,你将须要对返回的数据进行转换才干正确显示中文,日文等。仅供參考,转换为ATL CStringW的函数见下:
CStringW GetStringWFromUtf8( const std::string & str) { int len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), int(str.length()), 0, 0); CStringW buf; WCHAR* dd = buf.GetBuffer(len); len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), int(str.length()), dd, len); buf.ReleaseBuffer(len); return buf;} 完整代码例如以下:
1 // HttpPost.cpp written by l_zhaohui@163.com 2 // 2007/11/30 3 #include " stdafx.h " 4 #include < windows.h > 5 #include < stdio.h > 6 #include < stdlib.h > 7 8 #define _ATL_CSTRING_EXPLICIT_CONSTRUCTORS 9 #include < atlbase.h > 10 #include < atlstr.h > 11 12 #define USE_WINHTTP // Comment this line to user wininet. 13 #ifdef USE_WINHTTP 14 #include < winhttp.h > 15 #pragma comment(lib, " winhttp.lib " ) 16 # else 17 #include < wininet.h > 18 #pragma comment(lib, " wininet.lib " ) 19 #endif 20 #define BUF_SIZE ( 1024 ) 21 22 // CrackedUrl 23 class CrackedUrl { 24 int m_scheme; 25 CStringW m_host; 26 int m_port; 27 CStringW m_path; 28public: 29 CrackedUrl(LPCWSTR url) 30 { 31 URL_COMPONENTS uc = { 0}; 32 uc.dwStructSize = sizeof(uc); 33 34 const DWORD BUF_LEN = 256; 35 36 WCHAR host[BUF_LEN]; 37 uc.lpszHostName = host; 38 uc.dwHostNameLength = BUF_LEN; 39 40 WCHAR path[BUF_LEN]; 41 uc.lpszUrlPath = path; 42 uc.dwUrlPathLength = BUF_LEN; 43 44 WCHAR extra[BUF_LEN]; 45 uc.lpszExtraInfo = extra; 46 uc.dwExtraInfoLength = BUF_LEN; 47 48#ifdef USE_WINHTTP 49 if (!WinHttpCrackUrl(url, 0, ICU_ESCAPE, &uc)) { 50 printf("Error:WinHttpCrackUrl failed!/n"); 51 } 52 53#else 54 if (!InternetCrackUrl(url, 0, ICU_ESCAPE, &uc)) { 55 printf("Error:InternetCrackUrl failed!/n"); 56 } 57#endif 58 m_scheme = uc.nScheme; 59 m_host = host; 60 m_port = uc.nPort; 61 m_path = path; 62 } 63 64 int GetScheme() const 65 { 66 return m_scheme; 67 } 68 69 LPCWSTR GetHostName() const 70 { 71 return m_host; 72 } 73 74 int GetPort() const 75 { 76 return m_port; 77 } 78 79 LPCWSTR GetPath() const 80 { 81 return m_path; 82 } 83 84 static CStringA UrlEncode(const char* p) 85 { 86 if (p == 0) { 87 return CStringA(); 88 } 89 90 CStringA buf; 91 92 for (;;) { 93 int ch = (BYTE) (*(p++)); 94 if (ch == '/0') { 95 break; 96 } 97 98 if (isalnum(ch) || ch == '_' || ch == '-' || ch == '.') { 99 buf += (char)ch;100 }101 else if (ch == ' ') { 102 buf += '+';103 }104 else { 105 char c[16];106 wsprintfA(c, "%%%02X", ch);107 buf += c;108 }109 }110111 return buf;112 }113} ; 114 115 // CrackedUrl 116 HINTERNET OpenSession(LPCWSTR userAgent = 0 ) 117 { 118#ifdef USE_WINHTTP119 return WinHttpOpen(userAgent, NULL, NULL, NULL, NULL);;120#else121 return InternetOpen(userAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);122#endif123} 124 125 HINTERNET Connect(HINTERNET hSession, LPCWSTR serverAddr, int portNo) 126 { 127#ifdef USE_WINHTTP128 return WinHttpConnect(hSession, serverAddr, (INTERNET_PORT) portNo, 0);129#else130 return InternetConnect(hSession, serverAddr, portNo, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);131#endif132} 133 134 HINTERNET OpenRequest(HINTERNET hConnect, LPCWSTR verb, LPCWSTR objectName, int scheme) 135 { 136 DWORD flags = 0;137#ifdef USE_WINHTTP138 if (scheme == INTERNET_SCHEME_HTTPS) { 139 flags |= WINHTTP_FLAG_SECURE;140 }141142 return WinHttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags);143144#else145 if (scheme == INTERNET_SCHEME_HTTPS) { 146 flags |= INTERNET_FLAG_SECURE;147 }148149 return HttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags, 0);150#endif151} 152 153 BOOL AddRequestHeaders(HINTERNET hRequest, LPCWSTR header) 154 { 155 SIZE_T len = lstrlenW(header);156#ifdef USE_WINHTTP157 return WinHttpAddRequestHeaders(hRequest, header, DWORD(len), WINHTTP_ADDREQ_FLAG_ADD);158#else159 return HttpAddRequestHeaders(hRequest, header, DWORD(len), HTTP_ADDREQ_FLAG_ADD);160#endif161} 162 163 BOOL SendRequest(HINTERNET hRequest, const void * body, DWORD size) 164 { 165#ifdef USE_WINHTTP166 return WinHttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size, size, 0);167#else168 return HttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size);169#endif170} 171 172 BOOL EndRequest(HINTERNET hRequest) 173 { 174#ifdef USE_WINHTTP175 return WinHttpReceiveResponse(hRequest, 0);176#else177 // if you use HttpSendRequestEx to send request then use HttpEndRequest in here!178 return TRUE;179#endif180} 181 182 BOOL QueryInfo(HINTERNET hRequest, int queryId, char * szBuf, DWORD * pdwSize) 183 { 184#ifdef USE_WINHTTP185 return WinHttpQueryHeaders(hRequest, (DWORD) queryId, 0, szBuf, pdwSize, 0);186#else187 return HttpQueryInfo(hRequest, queryId, szBuf, pdwSize, 0);188#endif189} 190 191 BOOL ReadData(HINTERNET hRequest, void * buffer, DWORD length, DWORD * cbRead) 192 { 193#ifdef USE_WINHTTP194 return WinHttpReadData(hRequest, buffer, length, cbRead);195#else196 return InternetReadFile(hRequest, buffer, length, cbRead);197#endif198} 199 200 void CloseInternetHandle(HINTERNET hInternet) 201 { 202 if (hInternet)203 { 204#ifdef USE_WINHTTP205 WinHttpCloseHandle(hInternet);206#else207 InternetCloseHandle(hInternet);208#endif209 }210} 211 212 int _tmain( int argc, _TCHAR * argv[]) 213 { 214 HINTERNET hSession = 0;215 HINTERNET hConnect = 0;216 HINTERNET hRequest = 0;217 CStringW strHeader(L"Content-type: application/x-www-form-urlencoded/r/n");218219 // Test data220 CrackedUrl crackedUrl(L"http://www.easy-creator.net/test2/add.asp");221 CStringA strPostData("value1=10&value2=14");222223 // Open session.224 hSession = OpenSession(L"HttpPost by l_zhaohui@163.com");225 if (hSession == NULL) { 226 printf("Error:Open session!/n");227 return -1;228 }229230 // Connect.231 hConnect = Connect(hSession, crackedUrl.GetHostName(), crackedUrl.GetPort());232 if (hConnect == NULL) { 233 printf("Error:Connect failed!/n");234 return -1;235 }236237 // Open request.238 hRequest = OpenRequest(hConnect, L"POST", crackedUrl.GetPath(), crackedUrl.GetScheme());239 if (hRequest == NULL) { 240 printf("Error:OpenRequest failed!/n");241 return -1;242 }243244 // Add request header.245 if (!AddRequestHeaders(hRequest, strHeader)) { 246 printf("Error:AddRequestHeaders failed!/n");247 return -1;248 }249250 // Send post data.251 if (!SendRequest(hRequest, (const char*)strPostData, strPostData.GetLength())) { 252 printf("Error:SendRequest failed!/n");253 return -1;254 }255256 // End request257 if (!EndRequest(hRequest)) { 258 printf("Error:EndRequest failed!/n");259 return -1;260 }261262 char szBuf[BUF_SIZE];263 DWORD dwSize = 0;264 szBuf[0] = 0;265266 // Query header info.267#ifdef USE_WINHTTP268 int contextLengthId = WINHTTP_QUERY_CONTENT_LENGTH;269 int statusCodeId = WINHTTP_QUERY_STATUS_CODE;270 int statusTextId = WINHTTP_QUERY_STATUS_TEXT;271#else272 int contextLengthId = HTTP_QUERY_CONTENT_LENGTH;273 int statusCodeId = HTTP_QUERY_STATUS_CODE;274 int statusTextId = HTTP_QUERY_STATUS_TEXT;275#endif276 dwSize = BUF_SIZE;277 if (QueryInfo(hRequest, contextLengthId, szBuf, &dwSize)) { 278 szBuf[dwSize] = 0;279 printf("Content length:[%s]/n", szBuf);280 }281282 dwSize = BUF_SIZE;283 if (QueryInfo(hRequest, statusCodeId, szBuf, &dwSize)) { 284 szBuf[dwSize] = 0;285 printf("Status code:[%s]/n", szBuf);286 }287288 dwSize = BUF_SIZE;289 if (QueryInfo(hRequest, statusTextId, szBuf, &dwSize)) { 290 szBuf[dwSize] = 0;291 printf("Status text:[%s]/n", szBuf);292 }293294 // read data.295 for (;;) { 296 dwSize = BUF_SIZE;297 if (ReadData(hRequest, szBuf, dwSize, &dwSize) == FALSE) { 298 break;299 }300301 if (dwSize <= 0) { 302 break;303 }304305 szBuf[dwSize] = 0;306 printf("%s/n", szBuf); //Output value = value1 + value2307 }308309 CloseInternetHandle(hRequest);310 CloseInternetHandle(hConnect);311 CloseInternetHandle(hSession);312313 return 0;314} 315