VB - Rund um die CheckedListBox

  Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Text = "Demoprogramm für CheckListBox"
    ' Checken mit einen Click
    CheckedListBox1.CheckOnClick = True
    FillCheckedListBox(CheckedListBox1)
    Me.MinimumSize = Size
  End Sub

  ' --------------------------
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    FillCheckedListBox(CheckedListBox1)
  End Sub

  Sub FillCheckedListBox(ByVal ChLB As CheckedListBox)
    CheckedListBox1.Items.Clear()
    For m As Integer = 0 To 50
      CheckedListBox1.Items.Add("Item " & m.ToString)
    Next
  End Sub

  ' --------------------------
  Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    For m As Integer = 0 To CheckedListBox1.Items.Count - 1
      If CheckedListBox1.GetItemChecked(m) = True Then
        Dim Cancel As MsgBoxResult = MsgBoxResult.Ok
        Aktionen(m, Cancel)
        If Cancel = MsgBoxResult.Cancel Then Exit For
      End If
    Next
  End Sub

  Sub Aktionen(ByVal Ix As Integer, ByRef Cancel As MsgBoxResult)
    Select Case Ix
      ' ...
      Case Else
        Dim ant As MsgBoxResult = MsgBox("Aktion " & Ix.ToString & " noch nicht programmiert!".ToUpper, MsgBoxStyle.Information Or MsgBoxStyle.OkCancel)
        Cancel = ant
    End Select
  End Sub

  ' --------------------------
  Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
    OneCheckToggle(CheckedListBox1)
  End Sub

  Sub OneCheckToggle(ByVal ChLB As CheckedListBox)
    Dim m As Integer = ChLB.SelectedIndex
    If m = -1 Then Exit Sub
    Dim chst As CheckState
    Select Case ChLB.GetItemCheckState(m)
      Case CheckState.Unchecked
        chst = CheckState.Checked
      Case CheckState.Checked
        chst = CheckState.Unchecked
    End Select
    ChLB.SetItemCheckState(m, chst)
  End Sub

  ' --------------------------
  Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
    AllChecksToggle(CheckedListBox1)
  End Sub

  Sub AllChecksToggle(ByVal ChLB As CheckedListBox)
    For m As Integer = 0 To ChLB.Items.Count - 1
      Dim chst As CheckState
      Select Case CheckedListBox1.GetItemCheckState(m)
        Case CheckState.Unchecked
          chst = CheckState.Checked
        Case CheckState.Checked
          chst = CheckState.Unchecked
      End Select
      ChLB.SetItemCheckState(m, chst)
    Next
  End Sub

  ' --------------------------
  Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
    ClearSelected(CheckedListBox1)
  End Sub

  Sub ClearSelected(ByVal ChLB As CheckedListBox)
    ' ChLB.ClearSelected()

    ' alternativ
    ChLB.SelectedIndex = -1
  End Sub

  ' --------------------------
  Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
    RemoveCheckedItems(CheckedListBox1)
  End Sub

  Sub RemoveCheckedItems(ByVal ChLB As CheckedListBox)
    For m As Integer = ChLB.Items.Count - 1 To 0 Step -1
      If ChLB.GetItemChecked(m) = True Then
        ChLB.Items.RemoveAt(m)
      End If
    Next
  End Sub

  ' --------------------------
  Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
    RemoveNotCheckedItems(CheckedListBox1)
  End Sub

  Sub RemoveNotCheckedItems(ByVal ChLB As CheckedListBox)
    For m As Integer = ChLB.Items.Count - 1 To 0 Step -1
      If ChLB.GetItemChecked(m) = False Then
        ChLB.Items.RemoveAt(m)
      End If
    Next
  End Sub