Deselect Selecteditem in a Listbox

G

ghislain

New Member

Licensed User

• Jun 27, 2007

• #1

Hello!

I'm still working on my selection form..
Which has got a listbox. When nothing is selected the selectedindex = -1.
Now when i select something i can't deselect it anymore..
So I made up this deselect button with the following click-event:

myListbox.selectedIndex = -1

But this produces an [runtime] error everytime.
Does anybody have a suggestion?

Ghislain

 

Erel

B4X founder

Staff member

Licensed User

Longtime User

• Jun 27, 2007

• #2

Try to remove the selected item and then insert it again.

 

Cableguy

Expert

Licensed User

Longtime User

• Jun 27, 2007

• #3

If You don't require multiple selections then a radio button should be best for you....Check this code:

 

Attachments

• teste.zip

  1.1 KB · Views: 358

specci48

Well-Known Member

Licensed User

Longtime User

• Jun 27, 2007

• #4

Hi ghislain,

if I want to give the user the chance to deselect a listbox entry I'll do the following:
I add a "dummy"-entry at the first (or last) position of the listbox named "<no selection>" (or something like that) and pre-select this entry before showing the listbox.
Now you can proof during runtime, if the first (or last) entry is selected, which means, nothing is selected ...


specci48

 

G

ghislain

New Member

Licensed User

• Jun 27, 2007

• #5

Thanks for all the replies.
For the time being I will just refill my listbox. Which does the same trick as well. But it might become too slow when my list becomes longer and longer..
I hope in the future the functionality to deselect-all will be implemented..
Thanks!

 

Cableguy

Expert

Licensed User

Longtime User

• Jun 27, 2007

• #6

Have you tryied to set the index to -1?
That is , at least i think it is, the start point of any un-selected index..

 

B

Big JR

Member

Licensed User

Longtime User

• Jun 29, 2007

• #7

Ghislain started off setting the index to -1 but, as mentioned, that gives a runtime error. If you trap that error with an empty error handler you'll get the deselection without the error being reported.

Sub EventsList_LostFocus
ErrorLabel(ErrHandler)
EventsList.SelectedIndex = -1
return
ErrHandler:
End Sub

If your deselection comes within other code you'll need to have a goto to just after the selectedindex = -1 code.