VC：网络下载(WinInet)
WinInet开发：
1、添加一个下载按钮和一个保存地址按钮，和两个编辑框；并添加各自的变量；
2、C*Dlg类添加成员变量：
CString url;
CString savefilename;
3、保存地址按钮的消息映射函数：
void CTestDlg::OnWhere()
{
// TODO: Add your control notification handler code here
GetDlgItemText(IDC_URL,url);
if(url=="")
{
AfxMessageBox("请填入URL地址");
return;
}
//下面得到文件类型，即.后面的字符
CString aboutfile="";
int len = url.GetLength();
for(int i=len-1;url[i] != '.';i--)
aboutfile.Insert(0,url[i]);
CString strFileName,strFilePath;
CString m_szDir = "c:\\";
char BASED_CODE szFilter[] = "All Files (*.*)|*.*||";
CFileDialog OpenDlg(false, NULL, NULL, /*OFN_ALLOWMULTISELECT |*/ OFN_EXPLORER, szFilter);
OpenDlg.m_ofn.lStructSize = sizeof(OpenDlg.m_ofn);
OpenDlg.m_ofn.hwndOwner = NULL;
OpenDlg.m_ofn.lpstrTitle = "保存目标文件";
OpenDlg.m_ofn.lpstrInitialDir=m_szDir; //初始目录
if( OpenDlg.DoModal() == IDOK)
{
strFilePath = OpenDlg.GetPathName();
}
savefilename=strFilePath+"."+aboutfile;
SetDlgItemText(IDC_PATH,savefilename);
}
4、开始下载按钮的消息映射函数：
void CTestDlg::OnStart()
{
// TODO: Add your control notification handler code here
CInternetSession aInternetSession; //一个会话
CHttpConnection* pHttpConnection = NULL; //链接
CHttpFile* pHttpFile = NULL;
const TCHAR szHeaders[] = _T("Accept: */*\r\nUser-Agent: Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)\r\n"); //协议
DWORD dwFileStatus;
BYTE szBuffer[1024];
DWORD nLen;
CFile aFile;
DWORD nSuccess = -1;
CString strServer;
INTERNET_PORT nPort;
CString strObject;
DWORD dwServiceType;
DWORD dwDownloadSize = 0;
CString strLogs;
//分解URL
if(AfxParseURL(url, dwServiceType, strServer, strObject, nPort))
{
//如果服务类型不是HTTP下载
if(dwServiceType != AFX_INET_SERVICE_HTTP && dwServiceType != AFX_INET_SERVICE_HTTPS)
{
return;
}
}
while(pHttpConnection == NULL)
pHttpConnection = aInternetSession.GetHttpConnection(strServer, nPort);
if(pHttpConnection != NULL)
{
//取得HttpFile对象
pHttpFile = pHttpConnection->OpenRequest(CHttpConnection::HTTP_VERB_GET,
strObject,
NULL,
1,
NULL,
NULL,
INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE);
if(pHttpFile != NULL)
if(pHttpFile->AddRequestHeaders(szHeaders))
{
if(pHttpFile->SendRequest()) //发送文件请求
{
if(pHttpFile->QueryInfoStatusCode(dwFileStatus))//查询文件状态
{
if ((dwFileStatus/100)*100 == HTTP_STATUS_OK)//如果文件状态正常
{
if(aFile.Open(savefilename, CFile::modeCreate | CFile::modeWrite | CFile::typeBinary)) //打开文件
{
DWORD dwFileLen;
DWORD dwWordSize = sizeof(dwFileLen);
pHttpFile->QueryInfo(HTTP_QUERY_FLAG_NUMBER|HTTP_QUERY_CONTENT_LENGTH,&dwFileLen,&dwWordSize,NULL);
nLen = pHttpFile->Read(szBuffer, 1024);//接收数据
while(nLen >= 1024)//接收文件数据每次接收一个块
{
if(nLen > 0)//如果接收到数据
aFile.Write(szBuffer, nLen); //写入文件
nLen = pHttpFile->Read(szBuffer, 1024);//接收一个块的数据
}
if(nLen > 0)//如果接收到数据
{
aFile.Write(szBuffer, nLen);//写入文件
dwDownloadSize += nLen;
}
aFile.Close();//关闭文件
nSuccess = 0;//设置成功标志
AfxMessageBox("下载完成");
}
}
}
}
delete pHttpFile;
}
delete pHttpConnection;//删除http连接对象
}
aInternetSession.Close();//关闭http连接
}