Private Sub FindStringButton_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles FindStringButton.Click
Dim index As Integer = ListBox1.FindString(TextBox1.Text)
If (index < 0) Then
MessageBox.Show("找不到你要的選項.")
TextBox1.Text = String.Empty
Else
ListBox1.SelectedIndex = index
End If
End Sub