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IDropSource::QueryContinueDrag method (oleidl.h)

  • Article

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.

Syntax

HRESULT QueryContinueDrag(
  [in] BOOL  fEscapePressed,
  [in] DWORD grfKeyState
);

Parameters

[in] fEscapePressed

Indicates whether the Esc key has been pressed since the previous call to 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.

[in] grfKeyState

The current state of the keyboard modifier keys on the keyboard. Possible 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 value

This method can return the following values.

Return code Description
S_OK
 The drag operation should continue. This result occurs if no errors are detected, the mouse button starting the drag-and-drop 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.

Remarks

The DoDragDrop function calls QueryContinueDrag whenever it detects a change in the keyboard or mouse button state during a drag-and-drop operation. QueryContinueDrag must determine whether the drag-and-drop operation should be continued, canceled, or completed based on the contents of the parameters grfKeyState and fEscapePressed.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header oleidl.h

See also

DoDragDrop

IDropSource