MFASYNCRESULT structure (mfapi.h)

Contains data that is needed to implement the IMFAsyncResult interface.

Syntax

typedef struct tagMFASYNCRESULT : IMFAsyncResult {
  OVERLAPPED       overlapped;
  IMFAsyncCallback *pCallback;
  HRESULT          hrStatusResult;
  DWORD            dwBytesTransferred;
  HANDLE           hEvent;
} MFASYNCRESULT;

Inheritance

The MFASYNCRESULT structure implements IMFAsyncResult.

Members

overlapped

An OVERLAPPED structure. This structure is used internally to queue the work item. Fill this member with zeros.

pCallback

Pointer to the IMFAsyncCallback interface. This interface is implemented by the caller of the asynchronous method. This member can be NULL. If this member is NULL, the hEvent member must be a valid event handle.

hrStatusResult

The status code returned when this structure is used with an I/O completion port. You can also use this member to hold the status code for the asynchronous operation, returned by IMFAsyncResult::GetStatus.

dwBytesTransferred

The number of bytes transferred when this structure is used with an I/O completion port. This member is used internally by the work queue. Set this member to zero.

hEvent

Event handle. If pCallback is NULL, set this member to a valid event handle. The event is signaled when the work item is dispatched. Otherwise, set this member to NULL.

Remarks

Any custom implementation of the IMFAsyncResult interface must inherit this structure. For more information, see Custom Asynchronous Result Objects.

Requirements

See also

Custom Asynchronous Result Objects

Media Foundation Structures

Work Queues