ASP.NET - Hashtable 對(duì)象
Hashtable 對(duì)象包含用鍵/值對(duì)表示的項(xiàng)目。
創(chuàng)建 Hashtable
Hashtable 對(duì)象包含用鍵/值對(duì)表示的項(xiàng)目。鍵被用作索引，通過(guò)搜索其鍵，可以實(shí)現(xiàn)對(duì)值的快速搜索。
通過(guò) Add() 方法向 Hashtable 添加項(xiàng)目。
下面的代碼創(chuàng)建一個(gè)名為 mycountries 的 Hashtable，并添加了四個(gè)元素：
<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>
數(shù)據(jù)綁定
Hashtable 對(duì)象可為下面這些控件自動(dòng)地生成文本和值：
- asp:RadioButtonList
- asp:CheckBoxList
- asp:DropDownList
- asp:Listbox
如需把數(shù)據(jù)綁定到某個(gè) RadioButtonList 控件，首先請(qǐng)?jiān)谝粋�(gè) .aspx 頁(yè)面中創(chuàng)建 RadioButtonList 控件（沒有任何 asp:ListItem 元素）
<html>
<body>
<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>
</body>
</html>
然后添加構(gòu)建列表的腳本：
<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>
然后我們添加一個(gè)子例程，該例程會(huì)在用戶點(diǎn)擊 RadioButtonList 控件中的某個(gè)項(xiàng)目時(shí)被執(zhí)行。當(dāng)某個(gè)單選按鈕被點(diǎn)擊，label 中會(huì)出現(xiàn)一條文本：
<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>
注釋：您無(wú)法選擇添加到 Hashtable 的項(xiàng)目的排序方式。如需對(duì)項(xiàng)目進(jìn)行字母排序或數(shù)字排序，請(qǐng)使用 SortedList 對(duì)象。