URLOpenBlockingStream Function

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Creates a blocking type stream object from a URL and downloads the data from the Internet. When the data is downloaded, the client application or control can read it using the IStream::Read method.

Syntax

HRESULT URLOpenBlockingStream(
    LPUNKNOWN pCaller,
    LPCSTR szURL,
    LPSTREAM *ppStream,
    DWORD dwReserved,
    LPBINDSTATUSCALLBACK lpfnCB
);

Parameters

pCaller

Address of the controlling IUnknown interface. If the client application or control is not a COM object or ActiveX® control, the parameter can be set to NULL.

szURL

Address of a string value containing the URL to be converted to a stream object. This cannot be set to NULL.

ppStream

Address of the IStream interface on the stream object created by this function. The caller can read from the stream as soon as it has this pointer.

dwReserved

Reserved for future use. Must be zero.

lpfnCB

Address of the caller's IBindStatusCallback interface. This can be set to NULL.

Return Value

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

Remarks

This function is synchronous and will only return after all the data has been downloaded from the Internet.

URLOpenBlockingStream calls the IBindStatusCallback::OnProgress method (if provided) 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.

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