URLDownloadToFile 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
);

Parameters

pCaller

Address of the controlling IUnknown interface of the calling 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 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. This cannot be set to NULL.

szFileName

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

dwReserved

Reserved for future use. Must be zero.

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.

Return Value

Returns one of the following values:

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

Remarks

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

Function Information

Windows NT	Use version 4.0. Implemented as ANSI and Unicode functions.
Windows	Use Windows 95 and later. Implemented as ANSI and Unicode functions.
Header	Urlmon.h
Import Library	Urlmon.lib
Minimum availability	Internet Explorer 3.0