trying to do drag drop

  • Thread starter Thread starter active
  • Start date Start date
A

active

Code below.
Starting to use DragDrop and I get the message that the index is out of
range when I mouse down and move a little. The box has maybe 10 items and
I'm selecting one in the middle.

Second question. In the examples for ListBox they use:
alstFrom.SelectedItem.Text but when I add a dot after SelectedItem I get
only the option GetType. Can this be explained??

Finally. The conversion from VB6 placed ByRef with the first argument. Any
reason. Seems like ByVal would also work. In fact I think it would work even
if I wanted to make changes in the listbox. Is ByRef the preferred way.

Thanks for any insight passed along,
Cal

Private Sub MouseMoveHelper(ByRef alstFrom As System.Windows.Forms.ListBox,
ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
If e.Button = 0 Or alstFrom.Items.Count < 1 Or mbolDragProhibited Then Exit
Sub
Dim tbase As ListBox = DirectCast(sender, ListBox)
Dim data As New DataObject
data.SetData(DataFormats.Text, CStr(alstFrom.SelectedItem))
Dim effect As DragDropEffects = DragDropEffects.Move
effect = tbase.DoDragDrop(data, effect)
End Sub
 
active said:
Code below.
Starting to use DragDrop and I get the message that the index is out
of range when I mouse down and move a little. The box has maybe 10
items and I'm selecting one in the middle.
Click to expand...
Put a debug.writeline to send the co-ordinates to the output window. This
way you will see what you are trying to work with. I have found that the
screen co-ordinates sometimes need to be converted to the client
co-ordinates of the control. Using the PointToScreen co-ordinate in the
RectangleToScreen methods.

Second question. In the examples for ListBox they use:
alstFrom.SelectedItem.Text but when I add a dot after SelectedItem I
get only the option GetType. Can this be explained??
Click to expand...
Because you have not instantiated it as a New type of LitBoxItem. It
doesent know at pre run stage what it is. As a matter of course, use OPTION
STRICT, this will prevent late binding compilation and reduce the number of
these kinds of errors.
Finally. The conversion from VB6 placed ByRef with the first
argument. Any reason. Seems like ByVal would also work. In fact I
think it would work even if I wanted to make changes in the lis tbox.
Is ByRef the preferred way.
Click to expand...

It's up to you to use it as appropriate. If you specified ByVal on the VB6
code, it would translate it the same otherwise it will be byRef as default.

Regards OHM
 
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