Windows下比较简单的获取网页源码的方法

第一个方法是使用MFC里面的 <afxinet.h>

CString GetHttpFileData(CString strUrl)
{
CInternetSession Session("Internet Explorer", 0);
CHttpFile *pHttpFile = NULL;
CString strData;
CString strClip;
pHttpFile = (CHttpFile*)Session.OpenURL(strUrl);
while ( pHttpFile->ReadString(strClip) )
{
strData += strClip;
}
return strData;
}

要讲一下，pHttpFile->ReadString() 每次可能只读一个数据片断，读多少次取决于网络状况，所以要把每次读到的数据加到总数据的尾部，用了CString 省去了缓冲区处理:)
别忘了包含头文件#include <afxinet.h> 在工程设置，里面要选择 using MFC 要不然编译不了

第二种是使用WinNet的纯API实现的

#define MAXBLOCKSIZE 1024
#include <windows.h>
#include <wininet.h>

#pragma comment(lib, "wininet.lib")

void GetWebSrcCode(const char *Url);

int _tmain(int argc, _TCHAR* argv[])
{
GetWebSrcCode("http://www.cnblogs.com/");

return 0;
}

void GetWebSrcCode(const char *Url)
{
HINTERNET hSession = InternetOpen("zwt", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if (hSession != NULL)
{
HINTERNET hURL = InternetOpenUrl(hSession, Url, NULL, 0, INTERNET_FLAG_DONT_CACHE, 0);
if (hURL != NULL)
{
char Temp[MAXBLOCKSIZE] = {0};
ULONG Number = 1;

FILE *stream;
if( (stream = fopen( "E:\\test.html", "wb" )) != NULL )
{
while (Number > 0)
{
InternetReadFile(hURL, Temp, MAXBLOCKSIZE - 1, &Number);
fwrite(Temp, sizeof (char), Number , stream);
}
fclose( stream );
}

InternetCloseHandle(hURL);
hURL = NULL;
}

InternetCloseHandle(hSession);
hSession = NULL;
}
}

第三种就是使用非封装过的Socket实现了

int main(int argc, char* argv[])
{
SOCKET hsocket;
SOCKADDR_IN saServer;
WSADATA wsadata;
LPHOSTENT lphostent;
int nRet;
char Dest[3000];
char* host_name="blog.sina.com.cn";
char* req="GET /s/blog_44acab2f01016gz3.html HTTP/1.1\r\n"
"User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET4.0C; .NET4.0E; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)\r\n"
"Host:blog.sina.com.cn\r\n\r\n";

// 初始化套接字
if(WSAStartup(MAKEWORD(2,2),&wsadata))
printf("初始化SOCKET出错！");
lphostent=gethostbyname(host_name);
if(lphostent==NULL)
printf("lphostent为空！");
hsocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
saServer.sin_family = AF_INET;
saServer.sin_port = htons(80);
saServer.sin_addr =*((LPIN_ADDR)*lphostent->h_addr_list);
// 利用SOCKET连接
nRet = connect(hsocket,(LPSOCKADDR)&saServer,sizeof(SOCKADDR_IN));
if(nRet == SOCKET_ERROR)
{
printf("建立连接时出错！");
closesocket(hsocket);
return 0;
}
// 利用SOCKET发送

nRet = send(hsocket,req,strlen(req),0);
if(nRet==SOCKET_ERROR)
{
printf("发送数据包时出错！");
closesocket(hsocket);
}
nRet=1;
while(nRet>0)
{
// 接收返回数据包
nRet=recv(hsocket,(LPSTR)Dest,sizeof(Dest),0);
if(nRet>0)
Dest[nRet]=0;
else
Dest[0]=0;
char sDest[3000] = {0};
UTF8_2_GB2312(sDest,nRet,Dest,nRet);
// 显示返回数据包的大小、内容
//printf("\nReceived bytes:%d\n",nRet);
printf("Result:\n%s",sDest);
}
}

另外，以上我们获取网页的时候，获取到的可能是UTF8，似乎目前大多数网站都用的这种编码吧！下面是编码转换。

void UTF_8ToUnicode(wchar_t* pOut,char *pText)
{
char* uchar = (char *)pOut;
uchar[1] = ((pText[0] & 0x0F) << 4) + ((pText[1] >> 2) & 0x0F);
uchar[0] = ((pText[1] & 0x03) << 6) + (pText[2] & 0x3F);
}
void Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer)
{
::MultiByteToWideChar(CP_ACP,MB_PRECOMPOSED,gbBuffer,2,pOut,1);
}
void UTF_8ToGB2312(char*pOut, char *pText, int pLen)
{
char Ctemp[4];
memset(Ctemp,0,4);
int i =0 ,j = 0;
while(i < pLen)
{
if(pText[i] >= 0)
{
pOut[j++] = pText[i++];
}
else
{
WCHAR Wtemp;
UTF_8ToUnicode(&Wtemp,pText + i);
UnicodeToGB2312(Ctemp,Wtemp);
pOut[j] = Ctemp[0];
pOut[j + 1] = Ctemp[1];
i += 3;
j += 2;
}
}
pOut[j] ='\n';
return;
}

这是是转换成GB2312的代码