DeviceIoControl Codes

DeviceIoControl Codes

If you specified handling for IRP_MJ_DEVICE_CONTROL, the wizard will present a page (depicted in Figure B-3) to allow you to specify information about the control operations you support.

Figure B-3. Page for specifying supported I/O control operations.

Figure B-4 is an example of how you specify information about a particular DeviceIoControl operation. Most of the fields correspond directly to parameters in the CTL_CODE preprocessor macro and should therefore require no explanation. Setting the Asynchronous option generates support for an operation that you complete asynchronously after the dispatch function returns STATUS_PENDING.

Figure B-4. Dialog box for adding and editing an I/O control operation.