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IDropSource::QueryContinueDrag
Determines whether a drag-and-drop operation should be continued, canceled, or
completed. You do not call this method directly. The OLE DoDragDrop function calls this method during a drag-and-drop operation.
HRESULT QueryContinueDrag(
BOOL fEscapePressed,
| //Status of escape key since previous call
| DWORD grfKeyState
| //Current state of keyboard modifier keys
| );
|
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Parameters
fEscapePressed
[in] Specifies whether the Esc key has been pressed since the previous call to IDropSource::QueryContinueDrag or to DoDragDrop if this is the first call to QueryContinueDrag. A TRUE value indicates the end user has pressed the escape key; a FALSE
value indicates it has not been pressed.
grfKeyState
[in] Identifies the current state of the keyboard modifier keys on the
keyboard. Valid values can be a combination of any of the flags MK_CONTROL, MK_SHIFT,
MK_ALT, MK_BUTTON, MK_LBUTTON, MK_MBUTTON, and MK_RBUTTON.
Return Values
S_OK
The drag operation should continue. This result occurs if no errors are
detected, the mouse button starting the drag-and-rop operation has not been released,
and the Esc key has not been detected.
DRAGDROP_S_DROP
The drop operation should occur completing the drag operation. This result
occurs if grfKeyState indicates that the key that started the drag-and-drop operation has been
released.
DRAGDROP_S_CANCEL
The drag operation should be canceled with no drop operation occurring. This
result occurs if fEscapePressed is true indicating the Esc key has been pressed.
E_OUTOFMEMORY
Out of memory.
E_UNEXPECTED
An unexpected error occurred.
Comments
The DoDragDrop function calls IDropSource::QueryContinueDrag whenever it detects a change in the keyboard or mouse button state during a
drag-and-drop operation. IDropSource::QueryContinueDrag determines whether the drag-and-drop operation should be continued, canceled,
or completed based on the contents of the parameters grfKeyState and fEscapePressed.
See Also
DoDragDrop
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