如何在VB2012中为组合框添加唯一索引(不按顺序)

Private comboBoxValues As New List(Of String)

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    ' 初始化组合框的数据源
    comboBoxValues.Add("Value 1")
    comboBoxValues.Add("Value 2")
    comboBoxValues.Add("Value 3")
    ComboBox1.DataSource = comboBoxValues
End Sub

Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
    ' 检查唯一性
    Dim selectedValue As String = ComboBox1.SelectedItem.ToString()

    If Not comboBoxValues.Contains(selectedValue) Then
        ' 新值不存在，添加到数据源和集合中
        comboBoxValues.Add(selectedValue)
        ComboBox1.DataSource = Nothing
        ComboBox1.DataSource = comboBoxValues
    Else
        ' 新值已存在，根据需求进行处理
        MessageBox.Show("该值已存在！")
    End If
End Sub