### IDirectDraw2::WaitForVerticalBlank

The IDirectDraw2::WaitForVerticalBlank method helps the application synchronize itself with the vertical-blank interval.

HRESULT WaitForVerticalBlank(

DWORD dwFlags,

HANDLE hEvent

);

##### Parameters

dwFlags
  Determines how long to wait for the vertical blank.

  DDWAITVB_BLOCKBEGIN
  | Returns when the vertical-blank interval begins.
  DDWAITVB_BLOCKBEGINEVENT
  | Triggers an event when the vertical blank begins. This value is not currently supported.
  DDWAITVB_BLOCKEND
  | Returns when the vertical-blank interval ends and the display begins.

hEvent
  Handle of the event to be triggered when the vertical blank begins. This parameter is not currently used.

##### Return Values

If the method succeeds, the return value is DD_OK.

If the method fails, the return value may be one of the following error values:

DDERR_INVALIDOBJECT
DDERR_INVALIDPARAMS
DDERR_UNSUPPORTED
DDERR_WASSTILLDRAWING

##### See Also

IDirectDraw2::GetVerticalBlankStatus, IDirectDraw2::GetScanLine