ASP.NET Web Forms - SortedList 对象

SortedList 对象结合了 ArrayList 对象和 Hashtable 对象的特性。

Examples

尝试一下 - 实例

SortedList RadiobuttonList 1

SortedList RadiobuttonList 2

SortedList DropDownList

SortedList 对象

SortedList 对象包含用键/值对表示的项目。SortedList 对象按照字母顺序或者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。通过 TrimToSize() 方法把 SortedList 调整为最终尺寸。

下面的代码创建了一个名为 mycountries 的 SortedList 对象,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("N","Norway")  
mycountries.Add("S","Sweden")  
mycountries.Add("F","France")  
mycountries.Add("I","Italy")  
end if  
end sub  
</script>

数据绑定

SortedList 对象可为下列的控件自动生成文本和值:

  • asp:RadioButtonList
  • asp:CheckBoxList
  • asp:DropDownList
  • asp:Listbox

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 SortedList  
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:

实例

<script runat="server">  
sub Page_Load  
if Not Page.IsPostBack then  
dim mycountries=New SortedList  
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>

演示实例 ?