使用WinINet和WinHTTP实现Http访问

Http访问有两种方式，GET和POST，就编程来说GET方式相对简单点，它不用向服务器提交数据，在这个例程中我使用POST方式，提交数据value1与value2，并从服务器得到他们的和（value1 + value2）。

为实现Http访问，微软提供了二套API：WinINet, WinHTTP。WinHTTP比WinINet更加安全和健壮，可以这么认为WinHTTP是WinINet的升级版本。这两套API包含了很多相似的函数与宏定义，呵呵，详细对比请查阅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。代码如下:

#define USE_WINHTTP      //Comment this line to user wininet.

下面来说说实现Http访问的流程（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句柄与服务器连接得到一个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， 这时我们就可以使用这个request句柄来发送数据与读取从服务器返回的数据；

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，以便对比两套API函数的些许差异。下面让源代码说话，原工程是一个windows控制台工程，你可以很容易通过拷贝代码重建工程。

 

另：如果你从服务器得到的返回数据是utf8格式的文本数据，你将需要对返回的数据进行转换才能正确显示中文，日文等。仅供参考，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;
}

完整代码如下：

1// HttpPost.cpp written by [e-mail]

  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

 23class 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 }
110
111 return buf;
112 }
113};
114
115// CrackedUrl

116HINTERNET OpenSession(LPCWSTR userAgent = 0)
117{
118#ifdef USE_WINHTTP
119 return WinHttpOpen(userAgent, NULL, NULL, NULL, NULL);;
120#else
121 return InternetOpen(userAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
122#endif
123}
124
125HINTERNET Connect(HINTERNET hSession, LPCWSTR serverAddr, int portNo)
126{
127#ifdef USE_WINHTTP
128 return WinHttpConnect(hSession, serverAddr, (INTERNET_PORT) portNo, 0);
129#else
130 return InternetConnect(hSession, serverAddr, portNo, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
131#endif
132}
133
134HINTERNET OpenRequest(HINTERNET hConnect, LPCWSTR verb, LPCWSTR objectName, int scheme)
135{
136 DWORD flags = 0;
137#ifdef USE_WINHTTP
138 if (scheme == INTERNET_SCHEME_HTTPS) {
139 flags |= WINHTTP_FLAG_SECURE;
140 }
141
142 return WinHttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags);
143
144#else
145 if (scheme == INTERNET_SCHEME_HTTPS) {
146 flags |= INTERNET_FLAG_SECURE;
147 }
148
149 return HttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags, 0);
150#endif
151}
152
153BOOL AddRequestHeaders(HINTERNET hRequest, LPCWSTR header)
154{
155 SIZE_T len = lstrlenW(header);
156#ifdef USE_WINHTTP
157 return WinHttpAddRequestHeaders(hRequest, header, DWORD(len), WINHTTP_ADDREQ_FLAG_ADD);
158#else
159 return HttpAddRequestHeaders(hRequest, header, DWORD(len), HTTP_ADDREQ_FLAG_ADD);
160#endif
161}
162
163BOOL SendRequest(HINTERNET hRequest, const void* body, DWORD size)
164{
165#ifdef USE_WINHTTP
166 return WinHttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size, size, 0);
167#else
168 return HttpSendRequest(hRequest, 0, 0, const_cast<void*>(body), size);
169#endif
170}
171
172BOOL EndRequest(HINTERNET hRequest)
173{
174#ifdef USE_WINHTTP
175 return WinHttpReceiveResponse(hRequest, 0);
176#else
177 // if you use HttpSendRequestEx to send request then use HttpEndRequest in here!

178 return TRUE;
179#endif
180}
181
182BOOL QueryInfo(HINTERNET hRequest, int queryId, char* szBuf, DWORD* pdwSize)
183{
184#ifdef USE_WINHTTP
185 return WinHttpQueryHeaders(hRequest, (DWORD) queryId, 0, szBuf, pdwSize, 0);
186#else
187 return HttpQueryInfo(hRequest, queryId, szBuf, pdwSize, 0);
188#endif
189}
190
191BOOL ReadData(HINTERNET hRequest, void* buffer, DWORD length, DWORD* cbRead)
192{
193#ifdef USE_WINHTTP
194 return WinHttpReadData(hRequest, buffer, length, cbRead);
195#else
196 return InternetReadFile(hRequest, buffer, length, cbRead);
197#endif
198}
199
200void CloseInternetHandle(HINTERNET hInternet)
201{
202 if (hInternet)
203 {
204#ifdef USE_WINHTTP
205 WinHttpCloseHandle(hInternet);
206#else
207 InternetCloseHandle(hInternet);
208#endif
209 }
210}
211
212int _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");
218
219 // Test data

220 CrackedUrl crackedUrl(L"");
221 CStringA strPostData("value1=10&value2=14");
222
223 // Open session.

224 hSession = OpenSession(L"HttpPost by [e-mail]");
225 if (hSession == NULL) {
226 printf("Error:Open session!\n");
227 return -1;
228 }
229
230 // Connect.

231 hConnect = Connect(hSession, crackedUrl.GetHostName(), crackedUrl.GetPort());
232 if (hConnect == NULL) {
233 printf("Error:Connect failed!\n");
234 return -1;
235 }
236
237 // 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 }
243
244 // Add request header.

245 if (!AddRequestHeaders(hRequest, strHeader)) {
246 printf("Error:AddRequestHeaders failed!\n");
247 return -1;
248 }
249
250 // Send post data.

251 if (!SendRequest(hRequest, (const char*)strPostData, strPostData.GetLength())) {
252 printf("Error:SendRequest failed!\n");
253 return -1;
254 }
255
256 // End request

257 if (!EndRequest(hRequest)) {
258 printf("Error:EndRequest failed!\n");
259 return -1;
260 }
261
262 char szBuf[BUF_SIZE];
263 DWORD dwSize = 0;
264 szBuf[0] = 0;
265
266 // Query header info.

267#ifdef USE_WINHTTP
268 int contextLengthId = WINHTTP_QUERY_CONTENT_LENGTH;
269 int statusCodeId = WINHTTP_QUERY_STATUS_CODE;
270 int statusTextId = WINHTTP_QUERY_STATUS_TEXT;
271#else
272 int contextLengthId = HTTP_QUERY_CONTENT_LENGTH;
273 int statusCodeId = HTTP_QUERY_STATUS_CODE;
274 int statusTextId = HTTP_QUERY_STATUS_TEXT;
275#endif
276 dwSize = BUF_SIZE;
277 if (QueryInfo(hRequest, contextLengthId, szBuf, &dwSize)) {
278 szBuf[dwSize] = 0;
279 printf("Content length:[%s]\n", szBuf);
280 }
281
282 dwSize = BUF_SIZE;
283 if (QueryInfo(hRequest, statusCodeId, szBuf, &dwSize)) {
284 szBuf[dwSize] = 0;
285 printf("Status code:[%s]\n", szBuf);
286 }
287
288 dwSize = BUF_SIZE;
289 if (QueryInfo(hRequest, statusTextId, szBuf, &dwSize)) {
290 szBuf[dwSize] = 0;
291 printf("Status text:[%s]\n", szBuf);
292 }
293
294 // read data.

295 for (;;) {
296 dwSize = BUF_SIZE;
297 if (ReadData(hRequest, szBuf, dwSize, &dwSize) == FALSE) {
298 break;
299 }
300
301 if (dwSize <= 0) {
302 break;
303 }
304
305 szBuf[dwSize] = 0;
306 printf("%s\n", szBuf); //Output value = value1 + value2

307 }
308
309 CloseInternetHandle(hRequest);
310 CloseInternetHandle(hConnect);
311 CloseInternetHandle(hSession);
312
313 return 0;
314}
315