Search w3schools.com:

SHARE THIS PAGE

ASP.NET Web Forms - The SortedList Object

The SortedList object combines the features of both the ArrayList object and the Hashtable object.

Examples

Try it Yourself - Examples

SortedList RadiobuttonList 1

SortedList RadiobuttonList 2

SortedList DropDownList

The SortedList Object

The SortedList object contains items in key/value pairs. A SortedList object automatically sort the items in alphabetic or numeric order.

Items are added to the SortedList with the Add() method. A SortedList can be sized to its final size with the TrimToSize() method.

The following code creates a SortedList named mycountries and four elements are added:

<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>

Data Binding

A SortedList object may automatically generate the text and values to the following controls:

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

To bind data to a RadioButtonList control, first create a RadioButtonList control (without any asp:ListItem elements) in an .aspx page:

<html>
<body>

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

</body>
</html>

Then add the script that builds the list:

<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>

Then we add a sub routine to be executed when the user clicks on an item in the RadioButtonList control. When a radio button is clicked, a text will appear in a label:

Example

<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>

Show example »

W3Schools Certification

W3Schools' Online Certification

The perfect solution for professionals who need to balance work, family, and career building.

More than 10 000 certificates already issued!

Get Your Certificate »

The HTML Certificate documents your knowledge of HTML.

The HTML5 Certificate documents your knowledge of advanced HTML5.

The CSS Certificate documents your knowledge of advanced CSS.

The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.

The jQuery Certificate documents your knowledge of jQuery.

The XML Certificate documents your knowledge of XML, XML DOM and XSLT.

The ASP Certificate documents your knowledge of ASP, SQL, and ADO.

The PHP Certificate documents your knowledge of PHP and SQL (MySQL).

Your suggestion:

Close [X]

Thank You For Helping Us!

Your message has been sent to W3Schools.

Close [X]