URLOpenStream Function

---

Creates a push type stream object from a URL.

Syntax

HRESULT URLOpenStream(
    LPUNKNOWN pCaller,
    LPCSTR szURL,
    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 caller 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

String containing the URL to be converted to a stream object. This cannot be NULL.

dwReserved

Reserved for future use. Must be zero.

lpfnCB

Address of the caller's IBindStatusCallback interface, on which URLOpenStream calls IBindStatusCallback::OnDataAvailable when data arrives from the Internet. IBindStatusCallback::OnDataAvailable can return E_ABORT to abort the download.

Return Value

Returns S_OK if the operation succeeded, or E_OUTOFMEMORY if there was insufficient memory to complete the operation.

Remarks

The data is downloaded from the Internet as fast as possible. When data is available, it is pushed at the client 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