MFC网页访问的实现示例

本示例使用MFC 类CInternetSession 建立连接，使用 CHttpFile读取内容。

首先，建立一个MFC对话框项目，界面如下：

1. 添加头文件：

#include <afxinet.h>

2. UTF-8 转 UNICODE：

int cU8xU(wchar_t* pOut,char *pText)
{
	int ret = 0; 
	char* uchar = (char *)pOut; 
	unsigned cIn = (unsigned char)pText[0]; 
	if(cIn<0x80){ // ASCII 0x00 ~ 0x7f 
		pOut[0] = pText[0]; 
	}else if(cIn<0xdf){ 
		uchar[0] = (pText[0]<<6)|(pText[1]&0x3f); 
		uchar[1] = (pText[0]>>2)&0x0f; 
		ret = 1; 
	}else if(cIn<=0xef){ 
		uchar[0] = (pText[1]<<6)|(pText[2]&0x3f); 
		uchar[1] = (pText[0]<<4)|((pText[1]>>2)&0x0f); 
		ret = 2; 
	}else if(cIn<0xf7){ 
		uchar[0] = (pText[2]<<6)|(pText[3]&0x3f); 
		uchar[1] = (pText[1]<<4)|((pText[2]>>2)&0x0f); 
		uchar[2] = ((pText[0]<<2)&0x1c)|((pText[1]>>4)&0x03); 
		ret = 3; 
	} 
	return ret; 
}
int sU8xU(WCHAR* pOut,char *pText,int Len){ 
	int i,j; 
	for(i=0,j=0;i<Len;i++,j++){ 
		i+=cU8xU(&pOut[j],&pText[i]); 
	} 
	return j; 
}

3. 加入按键响应函数：

void CURL_TESTDlg::OnBnClickedButton1()
{
//#include <afxinet.h>
	CString url;
	GetDlgItem(IDC_EDIT1)->GetWindowText(url); 

	DWORD code = 0;
	CInternetSession httpSession ; 
	CHttpFile * htmlFile=NULL ;

	try{
		//打开网页 
		htmlFile=(CHttpFile*)httpSession.OpenURL(_T("http://www.sogou.com/")); 
		
		//htmlFile=(CHttpFile*)httpSession.OpenURL(url);
		htmlFile->QueryInfoStatusCode(code);
	}catch(...)
	{
		MessageBox(_T("err"),_T("BE"),1); // 如果断网而打不开这个网址，并且不抓取这个错误，就会弹出一个提示系统提示框！这里我自己处理。

		return;
	}

	//读取网页数据 
	CString str;
	CString info=_T("");
	while(htmlFile->ReadString(str))
	{   
		info+=str ;
	}

	//释放
	htmlFile->Close();
	httpSession.Close();

	//显示
	CString result;
	int length = info.GetLength();
	char *ab = new char[length];
	memset(ab, 0, length);
	memcpy(ab, info.GetBuffer(), length);
	WCHAR *big = new WCHAR[length];
	memset(big, 0, length);
	int len = sU8xU(big, ab, length);
	big[len] = '';
	delete []ab;
	
	CString temp(big);

	result.Format("The return code(返回值): %d
 %s", code, temp.GetBuffer());

	GetDlgItem(IDC_EDIT2)->SetWindowText(result); 
	//delete []big; // i don't how to do for this.
}

4. 另外也可以使用这段粗糙的代码实现这个功能：

	CInternetSession mysession;
	CHttpConnection *myconn=mysession.GetHttpConnection("www.veno2.com");

	CHttpFile *myfile=myconn->OpenRequest("GET","/ag_list");
	myfile->SendRequest();

	CString mystr;
	CString tmp;
	while(myfile->ReadString(tmp))
	{
		mystr+=tmp;
	}
	//GetDlgItem(IDC_EDIT2)->SetWindowText(mystr); 

	myfile->Close();
	myconn->Close();
	mysession.Close();
	delete myfile;
	delete myconn;
	myfile=0;
	myconn=0;