ASP.NET Hashtable
asp.net web forms - hashtable 對(duì)象
hashtable 對(duì)象包含用鍵/值對(duì)表示的項(xiàng)目。
嘗試一下 - 實(shí)例
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)建了一個(gè)名為 mycountries 的 hashtable 對(duì)象，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("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>
數(shù)據(jù)綁定
hashtable 對(duì)象可為下列的控件自動(dòng)生成文本和值：
- asp:radiobuttonlist
- asp:checkboxlist
- asp:dropdownlist
- asp:listbox
為了綁定數(shù)據(jù)到 radiobuttonlist 控件，首先要在 .aspx 頁(yè)面中創(chuàng)建一個(gè) radiobuttonlist 控件（不帶任何 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>
然后添加創(chuàng)建列表的腳本，并且綁定列表中的值到 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>
然后我們添加一個(gè)子例程，當(dāng)用戶(hù)點(diǎn)擊 radiobuttonlist 控件中的某個(gè)項(xiàng)目時(shí)，該子例程會(huì)被執(zhí)行。當(dāng)某個(gè)單選按鈕被點(diǎn)擊時(shí)，label 中會(huì)出現(xiàn)一行文本：
實(shí)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>
注釋?zhuān)?/b>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)行字母排序或者數(shù)字排序，請(qǐng)使用 sortedlist 對(duì)象。
ASP實(shí)戰(zhàn)