Checkedlistbox: uncheck items and re-run action upon new selection - vb.net

Question

I have a checkedlistbox1 which is filled through a search function with a folderbrowserdialog. Once I check one item (=XML file) it fills a listbox according to certain nodes by calling a separate class. This works fine.
What I want it to do next is when I select another item in checkedlistbox1 it unchecks the previously checked item and again runs the separate class to display the nodes of the newly selected item.
My code is a blur of tries according to other searches I've made. Please take note of what I want it to do, this is not like I have my code now because I don't want it to throw an error when I select another item. I just want it to de-select the previous and perform the action again on the newly selected item.
I hope someone can help me out on this one.
code:
Try
Dim checkLstBox As CheckedListBox = CType(sender, CheckedListBox)
Dim targetNum As Integer = 1
If e.NewValue = CheckState.Checked AndAlso checkLstBox.CheckedItems.Count + 1 > targetNum Then
Call ClsMessageBoxes.CheckedListbox1_maxcheck_Form2()
e.NewValue = CheckState.Unchecked
For i As Integer = 0 To f5.CheckedListBox1.Items.Count - 1
f5.CheckedListBox1.SetItemChecked(i, False)
Next 'This part at least throws an error if I select a new item in checkedlistbox1 and de-selects the previous item'
Else
'this part does not work'
f5.ListBoxDestPlate.Items.Clear()
f5.CheckedListlistbox2.SelectedItems.Clear()
'this part is meant to select an item in another checkbox according to certain tekst in the filename'
Dim i As Integer
If ClsSharedProperties2.filePath2.Contains("Text1") Then
i = 1
f5.Checkedlistbox2.SetItemChecked(i, True)
Call ClsScan.scanning2()
ElseIf ClsSharedProperties2.filePath2.Contains("Text2") Then
i = 2
f5.Checkedlistbox2.SetItemChecked(i, True)
Call ClsScan.scanning2()
End If
End If
Catch ex As Exception
MessageBox.Show(ex.Message & vbCrLf & "Stack Trace: " & vbCrLf & ex.StackTrace)
End Try

Answer 1

Your code is a bit messy with references to other forms I'm guessing (f5? ClsScan?).
In general, this code will work with the checked item and uncheck any existing items:
Private Sub clb_ItemCheck(sender As Object, e As ItemCheckEventArgs) Handles clb.ItemCheck
If e.NewValue = CheckState.Checked Then
For Each i As Integer In clb.CheckedIndices
clb.SetItemChecked(i, False)
Next
MessageBox.Show("Checked " & clb.Items(e.Index).ToString)
End If
End Sub
The MessageBox line would be replaced with you passing the item reference to whatever function or method you need to do your filtering.
One thing to note regarding the ItemCheck event is that the item in the collection isn't actually checked yet. That is why you would have to rely on the e.Index value.