使用WinINet和WinHTTP实现Http訪问
飘飘白云 l_zhaohui@163.com
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：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：
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 }
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"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
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315