| Microsoft DirectX 8.1 (C++) |
The IBDA_DeviceControl interface is implemented on all BDA device filters. The methods provided by this interface are called by a Network Provider to control a BDA device. Each instance of a device has one transaction list. A Network Provider first calls the StartChanges method. This deletes any previous uncommitted changes that were still pending. Then a Network Provider modifies whatever properties on the filter are required for the particular tuning operation. Then it calls the CheckChanges method to determine whether the modifications will be successful, without instructing the filter to actually make the changes. If this call succeeds, then a Network Provider calls CommitChanges to cause the filter to actually modify the specified properties. For more information, see “Changing BDA Filter Properties” in the Windows DDK.
In addition to the methods inherited from IUnknown, the IBDA_DeviceControl interface exposes the following methods.
| Method | Description |
| CheckChanges | Queries the device filter as to whether the changes that are pending would succeed if they were committed. |
| CommitChanges | Instructs the device to perform the changes specified in the previous call to StartChanges. |
| GetChangeState | Returns a value indicating whether any uncommitted changes are currently pending in the filter. |
| StartChanges | Called by a Network Provider before it begins to modify a set of properties on a BDA device filter. |