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WDF_REQUEST_TYPE enumeration (wudfddi_types.h)

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[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]

The WDF_REQUEST_TYPE enumeration identifies the types of I/O requests that a UMDF request object can represent.

Syntax

typedef enum _WDF_REQUEST_TYPE {
  WdfRequestUndefined,
  WdfRequestCreate,
  WdfRequestCleanup,
  WdfRequestRead,
  WdfRequestWrite,
  WdfRequestDeviceIoControl,
  WdfRequestClose,
  WdfRequestUsb,
  WdfRequestOther,
  WdfRequestInternalIoctl,
  WdfRequestTypeNoFormat,
  WdfRequestFlushBuffers,
  WdfRequestQueryInformation,
  WdfRequestSetInformation,
  WdfRequestMaximum
} WDF_REQUEST_TYPE, *PWDF_REQUEST_TYPE;

Constants

 
WdfRequestUndefined
The type of the request object is undefined.
WdfRequestCreate
The request object represents a file creation request. The driver receives this type of request object when an application opens a device by calling the Microsoft Win32 CreateFile function. The framework delivers this type of request, along with a newly created file object (IWDFFile), to the driver's IQueueCallbackCreate::OnCreateFile callback function. The new file object represents the HANDLE-typed file handle that the Win32 CreateFile returns.
WdfRequestCleanup
The request object represents a file cleanup request. The driver receives this type of request object after an application's call to the Win32 CloseHandle function closes the last handle to a file object, but possibly before all of the file's outstanding I/O requests have been completed or canceled. The framework delivers this type of request to the driver's IFileCallbackCleanup::OnCleanupFile callback function. (Also see WdfRequestClose.)
WdfRequestRead
The request object represents a read request. This driver receives this type of I/O request when an application calls the Win32 ReadFile or ReadFileEx function. The framework delivers this type of request to the driver's IQueueCallbackRead::OnRead callback function.
WdfRequestWrite
The request object represents a write request. This driver receives this type of I/O request when an application calls the Win32 WriteFile or WriteFileEx function. The framework delivers this type of request to the driver's IQueueCallbackWrite::OnWrite callback function.
WdfRequestDeviceIoControl
The request object represents a device I/O control request. This driver receives this type of I/O request when an application calls the Win32 DeviceIoControl function. The framework delivers this type of request to the driver's IQueueCallbackDeviceIoControl::OnDeviceIoControl callback function.
WdfRequestClose
The request object represents a file close request. The driver receives this type of request object after an application's call to the Win32 CloseHandle function closes the last handle to a file object, and after all of the file's outstanding I/O requests have been completed or canceled. The framework delivers this type of request to the driver's IFileCallbackClose::OnCloseFile callback function. (Also see WdfRequestCleanup.)
WdfRequestUsb
The request object was sent to a USB port. The IWDFRequestCompletionParams::GetCompletedRequestType method can return this value.
WdfRequestOther
This value is reserved for internal use only.
WdfRequestInternalIoctl
This value is reserved for internal use only.
WdfRequestTypeNoFormat
The request object's type has not been specified.
WdfRequestFlushBuffers
The request object represents a request to flush cached buffers. The framework delivers this type of request to the driver's IQueueCallbackDefaultIoHandler::OnDefaultIoHandler callback function.
WdfRequestQueryInformation
The request object represents a request to obtain information about a file. The framework delivers this type of request to the driver's IQueueCallbackDefaultIoHandler::OnDefaultIoHandler callback function.
WdfRequestSetInformation
The request object represents a request to set information about a file. The framework delivers this type of request to the driver's IQueueCallbackDefaultIoHandler::OnDefaultIoHandler callback function.
WdfRequestMaximum
The maximum value for the enumeration is exceeded.

Remarks

The WDF_REQUEST_TYPE enumeration is used as an input parameter of IWDFDevice::ConfigureRequestDispatching and IWDFIoQueue::ConfigureRequestDispatching. It is also used for the return value of IWDFIoRequest::GetType and IWDFRequestCompletionParams::GetCompletedRequestType.

For the KMDF version of this enumeration, see WDF_REQUEST_TYPE.

Requirements

Requirement Value
Header wudfddi_types.h (include Wudfddi.h)

See also

IFileCallbackCleanup::OnCleanupFile

IFileCallbackClose::OnCloseFile

IQueueCallbackCreate::OnCreateFile

IQueueCallbackDeviceIoControl::OnDeviceIoControl

IQueueCallbackRead::OnRead

IQueueCallbackWrite::OnWrite

IWDFFile