使用WinINet和WinHTTP实现Http访问

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：http://msdn2.microsoft.com/en-us/library/aa384068.aspx。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 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;
 28  public:
 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
116  HINTERNET 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
125  HINTERNET 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
134  HINTERNET 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
153  BOOL 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
163  BOOL 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
172 BOOL 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
182  BOOL 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
191  BOOL 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
200  void 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
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");
218
219    // Test data
220    CrackedUrl crackedUrl(L"http://www.easy-creator.net/test2/add.asp");
221    CStringA strPostData("value1=10&value2=14");
222
223    // 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    }
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