Most
of the GUI based application provides Drag-n-Drop operation. This function
enables the user to drag an item from one location and drop to another
location. In our previous post we have studied how to bind CheckedListBox using database. Now we will perform Drag-n-Drop operation with two CheckedListBox.
There
are series of events that needs to be handled to perform this Drag-n-Drop operation, these are:
MouseDown (of source control): this event is occur when the mouse pointer is over the control and
mouse button is pressed. It is beginning point of this operation, where DoDragDrop()
method is called to set the data that is to
be dragged.
DragEnter (of destination control): occur when mouse drag an item into
area of this control. Here, we check that the desired type of data are present
or not.
DragDrop (of destination control): occur when Drag-n-Drop operation completed. Here, we retrieve the
dragged data and drop it.
string[] items = new string[] { "item 1", "item 2", "item 3", "item 4", "item 5" };
checkedListBox1.Items.AddRange(items);
Steps
to perform this operation:
Step
1
Initiate
Drag-n-Drop operation for checkedListBox1 by calling DoDragDrop() method from
MouseDown event of the control.
Step
2
Handle
the event to provide information about the operation to the user i.e. DragEnter
event of checkedListBox2.
Step
3
To enable to checkedListBox2 to
accept the data, set its AllowDrop property to true.
checkedListBox2.AllowDrop = true;
Step
4
Handle
DragDrop event of checkedListBox2 to specifying what is to be done with dropped
data.
Download Example here.