How to Check or Uncheck all Items in VB.NET CheckedListBox Control

Question

I need to select and unselect all items in a VB.NET CheckedListBox control, what is the best way to do this?

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        With clbCheckedListBox

        .Items.Add("Select/UnSelect All")
        .Items.Add("Enero")
        .Items.Add("Febrero")
        .Items.Add("Marzo")
        .Items.Add("Abril")
        .Items.Add("Mayo")
        .Items.Add("Junio")
        .Items.Add("Julio")
        .Items.Add("Agosto")
        .Items.Add("Septiembre")
        .Items.Add("Octubre")
        .Items.Add("Noviembre")
        .Items.Add("Diciembre")

        .SelectedIndex = 0

    End With


End Sub


    Private Sub clbCheckedListBox_ItemCheck(sender As Object, e As System.Windows.Forms.ItemCheckEventArgs) Handles clbCheckedListBox.ItemCheck

    If e.Index = 0 Then

        If e.NewValue = CheckState.Checked Then

            For idx As Integer = 1 To Me.clbCheckedListBox.Items.Count - 1
                Me.clbCheckedListBox.SetItemCheckState(idx, CheckState.Checked)
            Next

        ElseIf e.NewValue = CheckState.Unchecked Then

            For idx As Integer = 1 To Me.clbCheckedListBox.Items.Count - 1
                Me.clbCheckedListBox.SetItemCheckState(idx, CheckState.Unchecked)
            Next

        End If

    End If

End Sub

After Hours the above code work fine for me !

Answer 1

Do you mean something like this:

Dim checked As Boolean = True   ' Set to True or False, as required.
For i As Integer = 0 To CheckedListBox1.Items.Count - 1
    CheckedListBox1.SetItemChecked(i, checked)
Next

Here I'm just looping through all the CheckedListBox Items and setting their checked state.

Answer 2

Ricardo, perhaps this might be what you are looking for:

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim items$() = New String() {"Select/UnSelect All", "Enero",
     "Febrero", "Marzo", "Abril", "Mayo", "Junio", "Julio",
     "Agosto", "Septiembre", "Octubre", "Noviembre", "Diciembre"}
    For Each Str As String In items : clbCheckedListBox.Items.Add(Str) : Next
End Sub ' Private Sub frmMain_Load(sender As System.Object, e As System.EventArgs)

Private Sub clbCheckedListBox_ItemCheck(sender As System.Object, e As System.Windows.Forms.ItemCheckEventArgs) Handles clbCheckedListBox.ItemCheck
    If e.Index = 0 Then
        Dim newCheckedState As CheckState = e.NewValue
        For idx As Integer = 1 To clbCheckedListBox.Items.Count - 1
            Me.clbCheckedListBox.SetItemCheckState(idx, newCheckedState)
        Next
    End If
End Sub

Answer 3

If button.Text = "Select All" Then
    For i As Integer = 0 To checklist.Items.Count - 1
        checklist.SetItemChecked(i, True)
    Next
    Button.Text = "Deselect All"
Else
    For i As Integer = 0 To checklist.Items.Count - 1
        checklist.SetItemChecked(i, False)
        Button.Text = "Select All"
    Next
End If

Answer 4

I found that clbCheckedListBox.clearSelection() works well for unselecting all.