ASP.NET - Object ng Hashtable

Ang object ng Hashtable ay naglalaman ng mga item na inilalarawan ng pares ng key/value.

Instance

Hashtable RadiobuttonList 1
Hashtable RadiobuttonList 2
Hashtable DropDownList

Magtatayo ng Hashtable

Ang object ng Hashtable ay naglalaman ng mga item na inilalarawan ng pares ng key/value. Ang key ay ginagamit bilang index, at pamamagitan ng paghahanap sa key, maaaring masagana ang paghahanap sa halaga.

Magdagdag ng item sa Hashtable sa pamamagitan ng Add() method.

Ang sumusunod na code ay nagtatayo ng isang Hashtable na may pangalan na mycountries at nagdagdag ng apat na elemento:

<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>

Data Binding

Ang object ng Hashtable ay maaaring gumawa ng teksto at halaga para sa mga sumusunod na control:

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

Upang i-bind ang data sa isang RadioButtonList control, unang makapaglilikha ng RadioButtonList control sa isang .aspx page (walang asp:ListItem element)

<html>
<body>
<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>
</body>
</html>

Pagkatapos, magdagdag ng script na magpapatayo ng listahan:

<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>

Pagkatapos, magdagdag tayo ng isang sub-procedure, na pupunta ito kapag ang isang item ng RadioButtonList control ay pinindot ng user.

<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>

แสดงตัวอย่างนี้

หมายเหตุ：คุณไม่สามารถเลือกวิธีการจัดลำดับของโครงการที่จะเพิ่มเข้ามาใน Hashtable ได้。หากต้องการจัดลำดับตามอักษรหรือตามตัวเลขของโครงการ โปรดใช้ตัวแปล SortedList。