| Microsoft DirectX 9.0 |
The IGraphVersion interface is implemented on the Filter Graph Manager to provide a way for plug-in distributors and applications to know when the graph has changed. If the graph has changed, and the application or plug-in distributor has an interface on a particular filter or pin, it should requery the graph to see if its pointers are still valid, or if there are new ones it should use.
In addition to the methods inherited from IUnknown, the IGraphVersion interface exposes the following method.
| Method | Description |
| QueryVersion | Retrieves the current graph version number. |