SortedList 对象兼有 ArrayList 和 Hashtable 对象的特性。
SortedList 对象
SortedList 对象包含用键/值对表示的项目。SortedList 对象可按照字符顺序或数字顺序自动地对项目进行排序。
通过 Add() 方法向 SortedList 添加项目。SortedList 可通过 TrimToSize() 方法调整为最终尺寸。
下面的代码创建了一个名为 mycountries 的 SortedList,并添加了四个元素:
<script runat="server"> sub Page_Load if Not Page.IsPostBack then dim mycountries=New SortedList mycountries.Add("C","China") mycountries.Add("S","Sweden") mycountries.Add("F","France") mycountries.Add("I","Italy") end if end sub </script>
数据绑定
SortedList 对象可自动地为下面的控件生成文本和值:
- asp:RadioButtonList
- asp:CheckBoxList
- asp:DropDownList
- asp:Listbox
如需把数据绑定到 RadioButtonList 控件,首先请在 aspx 文件中创建一个 RadioButtonList 控件(没有任何 asp:ListItem 元素):
<html> <body> <form runat="server"> <asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" /> </form> </body> </html>
然后添加构建列表的脚本:
<script runat="server"> sub Page_Load if Not Page.IsPostBack then dim mycountries=New SortedList mycountries.Add("C","China") mycountries.Add("S","Sweden") mycountries.Add("F","France") mycountries.Add("I","Italy") rb.DataSource=mycountries rb.DataValueField="Key" rb.DataTextField="Value" rb.DataBind() end if end sub </script> <html> <body> <form runat="server"> <asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" /> </form> </body> </html>
然后我们添加一个子例程,该子例程会在用户点击 RadioButtonList 控件中的项目时执行。当单选按钮被点击时,文本将出现在 label 中:
<script runat="server"> sub Page_Load if Not Page.IsPostBack then dim mycountries=New SortedList mycountries.Add("C","China") mycountries.Add("S","Sweden") mycountries.Add("F","France") mycountries.Add("I","Italy") rb.DataSource=mycountries rb.DataValueField="Key" rb.DataTextField="Value" rb.DataBind() end if end sub sub displayMessage(s as Object,e As EventArgs) lbl1.text="Your favorite country is: " & rb.SelectedItem.Text end sub </script> <html> <body> <form runat="server"> <asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" onSelectedIndexChanged="displayMessage" /> <p><asp:label id="lbl1" runat="server" /></p> </form> </body> </html>