URLDownloadToFile

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4/8/2010

This function downloads bits from the Internet and saves them to a file.

Syntax

HRESULT URLDownloadToFile(
  LPUNKNOWN pCaller,
  LPCTSTR szURL,
  LPCTSTR szFileName,
  DWORD dwReserved,
  LPBINDSTATUSCALLBACK lpfnCB
);

pCaller
Address of the controlling IUnknown interface of the calling Microsoft ActiveX component, if the caller is an ActiveX component. If the calling application is not an ActiveX component, this value can be set to NULL. Otherwise, the caller is a Component Object Model (COM) object that is contained in another component, such as an ActiveX Control within the context of an HTML page. This parameter represents the outermost IUnknown of the calling component. The function attempts the download within the context of the ActiveX client framework and allows the caller's container to receive callbacks on the progress of the download.

szURL
Address of a string value containing the URL to be downloaded. Cannot be set to NULL.

szFileName
Address of a string value containing the name of the file to create for bits that come from the download.

lpfnCB
Address of the caller's IBindStatusCallback interface. URLDownloadToFile calls this interface's IBindStatusCallback::OnProgress method on a connection activity, including the arrival of data. IBindStatusCallback::OnDataAvailable is never called. Implementing IBindStatusCallback::OnProgress allows a caller to implement a user interface or other progress monitoring functionality. It also allows the download operation to be canceled by returning E_ABORT from the IBindStatusCallback::OnProgress call. This can be set to NULL.

This function returns one of the values shown in the following table.

Value	Description
E_OUTOFMEMORY	The buffer length is invalid or there was insufficient memory to complete the operation.
S_OK	The operation succeeded.

The client can choose to be notified of progress through a notification callback.

Header	urlmon.h, urlmon.idl
Library	urlmon.lib
Windows Embedded CE	Windows CE .NET 4.0 and later
Windows Mobile	Windows Mobile Version 5.0 and later