c++请求url（c#获取网页内容）

我就废话不多说了，大家还是直接看代码吧~

以下内容摘自StackOverFlow 链接

1 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 #ifndef HTTPUTIL_H #define HTTPUTIL_H #include <windows.h> #include <string> #include <stdio.h> using std::string; #pragma comment(lib,"ws2_32.lib") void mParseUrl(char *mUrl, string &serverName, string &filepath, string &filename); SOCKET connectToServer(char *szServerName, WORD portNum); int getHeaderLength(char *content); char *readUrl2(char *szUrl, long &bytesReturnedOut, char **headerOut); char *sendRequest(char szUrl[]) { WSADATA wsaData; //char szUrl[] = "http://api.m.taobao.com/rest/api3.do?api=mtop.common.getTimestamp"; long fileSize; char *memBuffer, *headerBuffer; memBuffer = headerBuffer = nullptr; if (WSAStartup(0x101, &wsaData) != 0) return nullptr; memBuffer = readUrl2(szUrl, fileSize, &headerBuffer); printf("returned from readUrl\n"); printf("data returned:\n%s", memBuffer); if (fileSize != 0) { //delete (memBuffer); delete (headerBuffer); } WSACleanup(); return memBuffer; } void mParseUrl(char *mUrl, string &serverName, string &filepath, string &filename) { string::size_type n; string url = mUrl; if (url.substr(0, 7) == "http://") url.erase(0, 7); if (url.substr(0, 8) == "https://") url.erase(0, 8); n = url.find('/'); if (n != string::npos) { serverName = url.substr(0, n); filepath = url.substr(n); n = filepath.rfind('/'); filename = filepath.substr(n + 1); } else { serverName = url; filepath = "/"; filename = ""; } } SOCKET connectToServer(char *szServerName, WORD portNum) { struct hostent *hp; unsigned int addr; struct sockaddr_in server; SOCKET conn; conn = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (conn == INVALID_SOCKET) return NULL; if (inet_addr(szServerName) == INADDR_NONE) { hp = gethostbyname(szServerName); } else { addr = inet_addr(szServerName); hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET); } if (hp == nullptr) { closesocket(conn); return NULL; } server.sin_addr.s_addr = *((unsigned long *)hp->h_addr); server.sin_family = AF_INET; server.sin_port = htons(portNum); if (connect(conn, (struct sockaddr *)&server, sizeof(server))) { closesocket(conn); return NULL; } return conn; } int getHeaderLength(char *content) { const char *srchStr1 = "\r\n\r\n", *srchStr2 = "\n\r\n\r"; char *findPos; int ofset = -1; findPos = strstr(content, srchStr1); if (findPos != nullptr) { ofset = findPos - content; ofset += strlen(srchStr1); } else { findPos = strstr(content, srchStr2); if (findPos != nullptr) { ofset = findPos - content; ofset += strlen(srchStr2); } } return ofset; } char *readUrl2(char *szUrl, long &bytesReturnedOut, char **headerOut) { const int bufSize = 512; char readBuffer[bufSize], sendBuffer[bufSize], tmpBuffer[bufSize]; char *tmpResult = nullptr, *result; SOCKET conn; string server, filepath, filename; long totalBytesRead, thisReadSize, headerLen; mParseUrl(szUrl, server, filepath, filename); / step 1, connect // conn = connectToServer((char *)server.c_str(), 80); / step 2, send GET request / sprintf(tmpBuffer, "GET %s HTTP/1.0", filepath.c_str()); strcpy(sendBuffer, tmpBuffer); strcat(sendBuffer, "\r\n"); sprintf(tmpBuffer, "Host: %s", server.c_str()); strcat(sendBuffer, tmpBuffer); strcat(sendBuffer, "\r\n"); strcat(sendBuffer, "\r\n"); send(conn, sendBuffer, strlen(sendBuffer), 0); // SetWindowText(edit3Hwnd, sendBuffer); printf("Buffer being sent:\n%s", sendBuffer); / step 3 - get received bytes // Receive until the peer closes the connection totalBytesRead = 0; while (1) { memset(readBuffer, 0, bufSize); thisReadSize = recv (conn, readBuffer, bufSize, 0); if ( thisReadSize <= 0 ) break; tmpResult = (char *)realloc(tmpResult, thisReadSize + totalBytesRead); memcpy(tmpResult + totalBytesRead, readBuffer, thisReadSize); totalBytesRead += thisReadSize; } headerLen = getHeaderLength(tmpResult); long contenLen = totalBytesRead - headerLen; result = new char[contenLen + 1]; memcpy(result, tmpResult + headerLen, contenLen); result[contenLen] = 0x0; char *myTmp; myTmp = new char[headerLen + 1]; strncpy(myTmp, tmpResult, headerLen); myTmp[headerLen] = NULL; delete (tmpResult); *headerOut = myTmp; bytesReturnedOut = contenLen; closesocket(conn); return (result); } #endif // HTTPUTIL_H

测试代码：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 #include <string> #include <stdio.h> #include "HttpUtil.h" #include <iostream> using std::string; using namespace std; int main() { char *resData = sendRequest("http://api.m.taobao.com/rest/api3.do?api=mtop.common.getTimestamp"); string str = resData; cout << endl << str << endl; delete resData; return 0; }

补充知识：C++处理URL的方法，项目有用到，过程记录如下

由于这块需要转换成unicode码，也就是将字符串传换成unicode码，因此需要对输入的字符串做处理，同时又分两种情况，中文非中文的处理，要区别对待，首先要对输入的字符串进行识别：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 int 是不是中文(char *str) { char ch; while (1) { ch = *str++; if (ch == 0) { break; } if (ch&0x80) { if (*str & 0x80) { return true; } } else { return false; } } return 0; }

然后要进行相应转换

1 2 3 4 5 6 7 8 //--------------------------------------------------------------------- //函数：W2C //功能：将16位wchar_t转换为 8位char[2] //参数：w_cn为待转换的16位字符，c_cn[]为转换后的8位字符 //备注：wchar_t的高位字节应该存储在char数组的低位字节 //作者：xxxx //--------------------------------------------------------------------- void W2C(wchar_t w_cn , char c_cn[]){c_cn[0] = w_cn >> 8 ;c_cn[1] = (char)w_cn ;}

然后主体转换代码：

1 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 //------------------------------------------------------------------- //函数：ToHex //功能：将16位字符串转换为十六进制字符串 //参数：待转换的字符串，字符串长度 //返回值：转换后的字符串 //作者：xxxx //------------------------------------------------------------------- CString ToHex(CString Data, long nDataLength) { CString sResult; for (long nLoop=0; nLoop<nDataLength; nLoop++) { wchar_t ch = Data.GetAt(nLoop); CHAR buff[MAX_PATH] = {0}; LPCWSTR str = &ch; WideCharToMultiByte(CP_ACP, 0, (LPCWSTR)str, -1, buff, MAX_PATH, 0, 0); if (IncludeChinese(buff)) { char c_cn[2]={'0'}; W2C(ch,c_cn); static const char *hex = "0123456789ABCDEF"; for(int i=0;i<2;i++) { unsigned char chHexA = hex[((unsigned char)(c_cn[i]) >> 4) & 0x0f]; unsigned char chHexB = hex[(unsigned char)(c_cn[i]) & 0x0f]; sResult += (char)chHexA; sResult += (char)chHexB; } } else { sResult += ch; } } return sResult; }