<div>
<asp:ListBox ID="ListBox1" runat="server" Height="123px" Width="113px" SelectionMode="Multiple">
<asp:ListItem>tom</asp:ListItem>
<asp:ListItem>jion</asp:ListItem>
<asp:ListItem>j</asp:ListItem>
<asp:ListItem>l</asp:ListItem>
<asp:ListItem>k</asp:ListItem>
</asp:ListBox>
&nbsp;<asp:Button ID="btnAdd" runat="server" OnClick="btnAdd_Click" Text="添加" />
&nbsp;
<asp:Button ID="btnRemove" runat="server" Text="移除" OnClick="btnRemove_Click" />
&nbsp;<asp:ListBox ID="ListBox2" runat="server" Height="123px" SelectionMode="Multiple" Width="113px"></asp:ListBox>
</div>

protected void btnAdd_Click(object sender, EventArgs e)
{
#region listbox添加記錄的一種錯誤理解
//選擇多條記錄的時候,會有一條沒有被添加,這是因為當一條記錄被移除后,原來的第二條記錄的index為0
//for (int i = 0; i < ListBox1.Items.Count; i++)
//{
// if (ListBox1.Items[i].Selected == true)
// {
// ListBox2.Items.Add(ListBox1.SelectedValue);
// ListBox1.Items.Remove(ListBox1.SelectedValue);
// }
//}
#endregion
#region listbox利用index索引號進行添加的簡單寫法
//while (0 <= ListBox1.SelectedIndex)
//{
// ListBox2.Items.Add(ListBox1.SelectedItem);
// ListBox1.Items.Remove(ListBox1.SelectedItem);
//}
#endregion
#region listbox的另一種成功添加方法
List<ListItem> list = new List<ListItem>();
for (int i = ListBox1.Items.Count - 1; i >= 0; i--)
{
if (ListBox1.Items[i].Selected == true)
{
list.Add(ListBox1.Items[i]);
ListBox1.Items.Remove(ListBox1.Items[i]);
}
}
for (int i = 0; i <=list.Count - 1; i++)
{
ListBox2.Items.Add(list[i]);
}
#endregion
}
protected void btnRemove_Click(object sender, EventArgs e)
{
while (0 <= ListBox2.SelectedIndex)
{
ListBox1.Items.Add(ListBox2.SelectedItem);
ListBox2.Items.Remove(ListBox2.SelectedItem);
}
}