CWebGrab
is a simple class that allows you to quickly and easily download files from the net. The class is merely a light wrapper for the MFC internet classes, and as such supports any protocol that the MFC classes support.
The class is extremely simple to use and has only one main function that you need to call: CWebGrab::GetFile
. The syntax is:
BOOL GetFile(LPCTSTR szURL, CString& strBuffer,
LPCTSTR szAgentName = NULL, CWnd* pWnd = NULL);
Downloads a file from the given URL
szURL
is the URL
strBuffer
is a CString
buffer that will hold the contents of the downloaded file
szAgentName
is the agent name you want to send to the website (may be NULL)
pWnd
is a status window. Status updates will be sent to this window using SetWindowText()
BOOL GetFileInfo(LPCTSTR szURL, CString& strLastModified, DWORD& dwSize,
DWORD& dwServerError, LPCTSTR szAgentName = NULL,
CWnd* pWnd = NULL);
(Added by Ravi Bhavnani) Retrieves the information about a file from the given URL
szURL
is the URL
strLastModified
is a CString
buffer that will hold the last modified date of the file
dwServerError
will return any error codes that were raised.
szAgentName
is the agent name you want to send to the website (may be NULL)
pWnd
is a status window. Status updates will be sent to this window using SetWindowText()
Bryce Burrows kindly updated the code to include the following functions:
void SetUseProxy(bool use);
Sets whether or not to use a proxy
void SetProxyServer(LPCSTR server);
Sets the proxy server
void SetProxyPort(UINT port);
Sets the proxy port
void SetProxy(LPCSTR proxy, WORD port, bool use=true);
Sets the proxy information in one call
void SetForceReload (bool bForceReload)
Sets whether or not to force a reload when downloading a document. If a force reload is set the the document will not be a cached version.
void GetForceReload()
Gets whether or not to force a reload when downloading a document.
void SetTimeOut(DWORD timeOut);
Sets the timeout for the operation
double GetRate();
Retrieves the download rate in Kb/sec
SHORT GetErrorCode();
CString GetErrorMessage();
Get the error code and message (if any)
Example of use
#include "webgrab.h"
void CWebGrabberDlg::OnDownload()
{
CString strBuffer;
CWebGrab grab;
if (grab.GetFile("http://www.mysite.com/index.htm",
strBuffer,
_T("WebGrab demo"),
GetDlgItem(IDC_STATUS)))
{
TRACE0("everything went OK\n")
}
}
History
26 Jan 2002 - Bryce Burrows kindly added the proxy code.
16 Feb 2002 - Bryce Burrows source code update.
2 Mar 2002 - Ravi Bhavnani added a "force reload" option to ensure that the downloaded data is not read from the cache, plus Get/SetForceReload()
functions.
17 Apr 2002 - Ravi Bhavnani added a GetFileInfo