ASP.NET Hashtable
asp.net web forms - hashtable 对象
hashtable 对象包含用键/值对表示的项目。
尝试一下 - 实例
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>
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>
数据绑定
hashtable 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>
<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>
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：
实例
<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>
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。
ASP实战