This is a very common requirement in applications and one that I always need to think a few extra minutes (hours, if you want) before I get it.
The GUI contains a CheckedListBox (or any other list) and the user want to be able to move the items up and down in the list. Yes I know - it seems trivial at first…
Here is one solution that uses a single method that is called with a parameter to indicate if the item is to be moved up or down.
’’’ ‘’’ Moves an item in the listbox ‘’’ Private Sub MoveItemInListbox(ByVal up As Boolean) ‘ Check that something is selected If chklst.SelectedItem Is Nothing Then MessageBox.Show(“Nothing selected”) Exit Sub End If ‘ No flicker - on
' Remember the selected stuff, index, the item itself and if the item is
' checked or not
Dim selectedIndex As Integer = chklst.SelectedIndex
Dim selectedItem As Object = chklst.SelectedItem
Dim checked As Boolean = chklst.GetItemChecked(selectedIndex)
’ Remove the item
' Calculate the new index
Dim newIndex As Integer = selectedIndex
If up Then
newIndex = newIndex - 1
Else
newIndex = newIndex + 1
End If
’ Check that the index is within our bounds If nyttIndex > chklstStycken.Items.Count - 1 Or nyttIndex < 0 Then Exit Sub End If ‘ Put the item back in the list and check it if needed chklst.Items.Insert(newIndex , selectedItem) chklst.SetItemChecked(newIndex , checked) ‘ Set focus on the moved item chklstStycken.SelectedIndex = newIndex chklstStycken.EndUpdate() end sub
Yeah - i’ve ripped the solution from http://www.msnewsgroups.net/group/microsoft.public.dotnet.languages.csharp/topic21474.aspx, if you don’t trust me.