创建 Hashtable
Hashtable 对象包含用键/值对表示的项目。键被用作索引,通过搜索其键,可以实现对值的快速搜索。
通过 Add() 方法向 Hashtable 添加项目。
下面的代码创建一个名为 mycountries 的 Hashtable,并添加了四个元素:
![](/Images/OutliningIndicators/ContractedBlock.gif)
Code
<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
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
Hashtable 对象可为下面这些控件自动地生成文本和值:
- asp:RadioButtonList
- asp:CheckBoxList
- asp:DropDownList
- asp:Listbox
如需把数据绑定到某个 RadioButtonList 控件,首先请在一个 .aspx 页面中创建 RadioButtonList 控件(没有任何 asp:ListItem 元素)
![](/Images/OutliningIndicators/ContractedBlock.gif)
Code
<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:
![](/Images/OutliningIndicators/ContractedBlock.gif)
Code
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
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,该例程会在用户点击 RadioButtonList 控件中的某个项目时被执行。当某个单选按钮被点击,label 中会出现一条文本
![](/Images/OutliningIndicators/ContractedBlock.gif)
Code
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
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>