WdfDeviceGetIoTarget method
[Applies to KMDF and UMDF]
The WdfDeviceGetIoTarget method returns a handle to a function or filter driver's local I/O target, for a specified device.
Syntax
WDFIOTARGET WdfDeviceGetIoTarget(
[in] WDFDEVICE Device
);
Parameters
- Device [in]
-
A handle to a framework device object.
Return value
If the operation succeeds, WdfDeviceGetIoTarget returns a handle to a framework I/O target object. If the specified framework device object represents a PDO, the method returns NULL.
A bug check occurs if the driver supplies an invalid object handle.
Remarks
When a UMDF driver sends a driver-created request to a local I/O target, the request has no associated file object. Some lower targets, such as a HIDClass-enumerated raw PDO, fail requests that have no associated file object. In this situation, a UMDF driver can specify WdfIoTargetOpenLocalTargetByFile to create an I/O target that represents the lower stack (just like a local target) using a file handle. As a result, any driver-created requests sent to this I/O target are associated with the file object corresponding to the handle opened. To do so, call the WDF_IO_TARGET_OPEN_PARAMS_INIT_OPEN_BY_FILE function before calling WdfIoTargetOpen.
For more information about I/O targets, see Using I/O Targets.
Examples
The following code example obtains a handle to a specified device's local I/O target.
WDFIOTARGET ioTargetHandle; ioTargetHandle = WdfDeviceGetIoTarget(device);
Requirements
|
Minimum KMDF version | 1.0 |
|---|---|
|
Minimum UMDF version | 2.0 |
|
Header |
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Library |
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IRQL | <= DISPATCH_LEVEL |
|
DDI compliance rules | DriverCreate, KmdfIrql, KmdfIrql2 |
