How to Use UMDF COM Objects
COM programming has two aspects: implementing clients that use existing COM objects and implementing your own COM objects. These two aspects are not mutually exclusive because COM objects are often clients of other COM objects. Both UMDF drivers and the UMDF runtime function as COM clients:
UMDF drivers use UMDF-provided COM objects to interact with the UMDF runtime.
For example, the UMDF-provided framework device object represents the device. Drivers are clients of the framework device object, which drivers use for tasks such as setting or retrieving the device’s Plug and Play state.
The UMDF runtime uses driver-provided, COM-based callback objects to interact with drivers.
For example, a driver can create one or more ...