This function downloads bits from the Internet and saves them to a file.
HRESULT URLDownloadToFile( LPUNKNOWN pCaller, LPCTSTR szURL, LPCTSTR szFileName, DWORD dwReserved, LPBINDSTATUSCALLBACK lpfnCB );
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.
Address of a string value containing the URL to be downloaded. Cannot be set to NULL.
Address of a string value containing the name of the file to create for bits that come from the download.
Reserved. Must be zero.
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.