ListBox 項目的向上 向下移動

ASP<asp:ListBox ID="ListBox1" runat="server" Height="100px" Width="200px">    <asp:ListItem>台灣</asp:ListItem>    <asp:ListItem>日本</asp:ListItem>    <asp:ListItem>英國</asp:ListItem>    <asp:ListItem>西班牙</asp:ListItem>    <asp:ListItem>義大利</asp:ListItem></asp:ListBox><asp:Button ID="Button1" runat="server" Text="向上" /><asp:Button ID="Button2" runat="server" Text="向下" />


.VB
向下
rotected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
   Dim index As Integer = ListBox1.SelectedIndex

   If index > 0 Then
       Dim item As ListItem = ListBox1.Items(index)
       ListBox1.Items.RemoveAt(index)
       ListBox1.Items.Insert(index - 1, item)
   End If
nd Sub

向下
rotected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
   Dim index As Integer = ListBox1.SelectedIndex

   If index < ListBox1.Items.Count - 1 Then
       Dim item As ListItem = ListBox1.Items(index)
       ListBox1.Items.RemoveAt(index)
       ListBox1.Items.Insert(index + 1, item)

   End If
End Sub