Specifies which drag-and-drop operations are allowed; can be set to specify the current drag-and-drop operation.
public int effect;
The value of the effect field passed with an event initially represents the drag-and-drop effects allowed for the control. The value passed is the result of applying the bitwise OR operation (|) to constants defined in the DragDropEffect class. You can use the effect field to store the current drag-and-drop effect. This information can be used to optimize a drag-and-drop operation, as shown in the following code:
private int effect = 0; private void testControl_dragEnter(Object sender, DragEvent e) { // Check if the COPY effect is allowed. if ((e.effect & DragDropEffect.COPY) != 0) { // If so, set the current effect to COPY. e.effect = DragDropEffect.COPY; } // Store the current effect. This can then be used to optimize the // dragOver event handler. effect = e.effect; } private void testControl_dragOver(Object sender, DragEvent e) { // Set the effect for the dragOver event to the current effect. e.effect = effect; }