Add a CheckBox control above the CheckedListBox. You'll need to handle the new CheckBox's
CheckChanged
event. Note that the second parameter in the
SetItemChecked
command is a boolean that gets the
Checked
property of CheckBox1. Assuming you have a CheckBox named CheckBox1 and a CheckedListBox control named CheckedListBox1, this code will get it done:
Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged
For l As Integer = 0 To CheckedListBox1.Items.Count - 1
CheckedListBox1.SetItemChecked(l, CheckBox1.Checked)
Next
End Sub