SelectedIndexChanged gives exeption?

SelectedIndexChanged gives exeption?

• vanWeyden

  Yep. it wil do it every time. Did it as far back as the first version of this product. Why Because setting the index to zero causes an exception but is not raised until you fire the event the second time.

  Comes back with:

  Value of '0' is not a valid for 'index'.
  Parameter name: index

  Try one of these.

  Dim this As Integer = DirectCast(ListView1.SelectedItems(0), ListViewItem).Index

  Dim this As Integer = CType(ListView1.SelectedItems(0), ListViewItem).Index

  
  

• ssbeginner

  Sorry redwar but that's not going to work. If there are no SelectedIndices then there are no SelectedItems either. The problem is that the first time you select an item you are going from no selected items to one selected item, which is no problem. The next time you select a different item the first thing that happens is the first item is unselected then the new item is selected. This means that the SelectedIndexChanged event is raised twice, once as it the number of selected items changes from 1 to 0 and then again when it changes from 0 to 1. Try this code to see what I mean:

  Private Sub ListView1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.SelectedIndexChanged

  MessageBox.Show(Me.ListView1.SelectedIndices.Count.ToString())

  End Sub

  This means that you need to test that there are selected items before you try to access them.

  
  

• Naldo Alcalde Huamán

  Thanks, I get it... the event fires twice, when the "old" selected item is deselected, and then again when the "new" item is selected.

  checking for a SelectedIndices.count larger than 0 before using SelectedIndices(0) did the job.

  Thanks again

  
  
• SelectedIndexChanged gives exeption?