Hashtable 对象包含用键/值对表示的项目。键被用作索引,通过搜索键,可以实现对值的快速搜索。
通过 Add() 方法向 Hashtable 添加项目。
下面的代码创建了一个名为 mycountries 的 Hashtable 对象,并添加了四个元素:
<script runat="server"> Sub Page_Load if Not Page.IsPostBack then dim mycountries=New Hashtable mycountries.Add("N","Norway") mycountries.Add("S","Sweden") mycountries.Add("F","France") mycountries.Add("I","Italy") end if end sub </script>
Hashtable 对象可为下列的控件自动生成文本和值:
为了绑定数据到 RadioButtonList 控件,首先要在 .aspx 页面中创建一个 RadioButtonList 控件(不带任何 asp:ListItem 元素):
<html> <body> <form runat="server"> <asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" /> </form> </body> </html>然后添加创建列表的脚本,并且绑定列表中的值到 RadioButtonList 控件:
<script runat="server"> sub Page_Load if Not Page.IsPostBack then dim mycountries=New Hashtable mycountries.Add("N","Norway") 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,当用户点击 RadioButtonList 控件中的某个项目时,该子例程会被执行。当某个单选按钮被点击时,label 中会出现一行文本:
<script runat="server"> sub Page_Load if Not Page.IsPostBack then dim mycountries=New Hashtable mycountries.Add("N","Norway") 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>
注释:
您无法选择添加到 Hashtable 的项目的排序方式。如需对项目进行字母排序或者数字排序,请使用 SortedList 对象。