使用WinINet和WinHTTP实现Http訪问
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:
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:
// HttpPost.cpp written by l_zhaohui@163.com2
// 2007/11/303
#include "stdafx.h"4
#include <windows.h>5
#include <stdio.h>6
#include <stdlib.h>7

8
#define _ATL_CSTRING_EXPLICIT_CONSTRUCTORS9
#include <atlbase.h>10
#include <atlstr.h>11

12
#define USE_WINHTTP //Comment this line to user wininet.13
#ifdef USE_WINHTTP14
#include <winhttp.h>15
#pragma comment(lib, "winhttp.lib")16
#else17
#include <wininet.h>18
#pragma comment(lib, "wininet.lib")19
#endif20
#define BUF_SIZE (1024)21

22
// CrackedUrl23
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_WINHTTP49
if (!WinHttpCrackUrl(url, 0, ICU_ESCAPE, &uc)) {50
printf("Error:WinHttpCrackUrl failed!/n");51
}52

53
#else54
if (!InternetCrackUrl(url, 0, ICU_ESCAPE, &uc)) {55
printf("Error:InternetCrackUrl failed!/n");56
}57
#endif58
m_scheme = uc.nScheme;59
m_host = host;60
m_port = uc.nPort;61
m_path = path;62
}63

64
int GetScheme() const65
{66
return m_scheme;67
}68

69
LPCWSTR GetHostName() const70
{71
return m_host;72
}73

74
int GetPort() const75
{76
return m_port;77
}78

79
LPCWSTR GetPath() const80
{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
// CrackedUrl116
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
}141

142
return WinHttpOpenRequest(hConnect, verb, objectName, NULL, NULL, NULL, flags);143

144
#else145
if (scheme == INTERNET_SCHEME_HTTPS) {146
flags |= INTERNET_FLAG_SECURE;147
}148

149
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");218

219
// Test data220
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 request257
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_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
}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 + value2307
}308

309
CloseInternetHandle(hRequest);310
CloseInternetHandle(hConnect);311
CloseInternetHandle(hSession);312

313
return 0;314
}315




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