IGraphVersion Interface

The IGraphVersion interface is provided by the filter graph manager to let other objects, especially plug-in distributors and the Graphedt.exe tool, know when the graph has changed.

This interface is implemented by the filter graph manager.

Use this interface if your application or plug-in distributor must know when filters have been added, deleted, or reconnected.

Methods in Vtable Order

IUnknown methods Description
QueryInterface Retrieves pointers to supported interfaces.
AddRef Increments the reference count.
Release Decrements the reference count.

IGraphVersion methods Description
QueryVersion Retrieves the current graph version number.

IUnknown methods	Description
QueryInterface	Retrieves pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.
IGraphVersion methods	Description
QueryVersion	Retrieves the current graph version number.

IGraphVersion::QueryVersion

IGraphVersion Interface

Retrieves the current graph version number.

Syntax

HRESULT QueryVersion(
    LONG *pVersion
    );

Parameters

pVersion
Pointer to the current graph version.

Return Value

Returns an HRESULT value that depends on the implementation. HRESULT can be one of the following standard constants, or other values not listed.

E_FAIL Failure.
E_POINTER Null pointer argument.
E_INVALIDARG Invalid argument.
E_NOTIMPL Method isn't supported.
S_OK or NOERROR Success.

Remarks

The version number is incremented every time there is a change in the set of filters in the graph or in their connections. If the version number has changed since the last enumeration, the graph must be re-enumerated.

E_FAIL	Failure.
E_POINTER	Null pointer argument.
E_INVALIDARG	Invalid argument.
E_NOTIMPL	Method isn't supported.
S_OK or NOERROR	Success.