W3Schools.com

ASP.NET - The ArrayList Object


The ArrayList object is a collection of items containing a single data value.


Examples

Try it Yourself - Examples

ArrayList DropDownList

ArrayList RadioButtonList


Create an ArrayList

The ArrayList object is a collection of items containing a single data value.

Items are added to the ArrayList with the Add() method.

The following code creates a new ArrayList object named mycountries and four items are added:

<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New ArrayList
  mycountries.Add("Norway")
  mycountries.Add("Sweden")
  mycountries.Add("France")
  mycountries.Add("Italy")
end if
end sub
</script>

By default, an ArrayList object contains 16 entries. An ArrayList can be sized to its final size with the TrimToSize() method:

<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New ArrayList
  mycountries.Add("Norway")
  mycountries.Add("Sweden")
  mycountries.Add("France")
  mycountries.Add("Italy")
  mycountries.TrimToSize()
end if
end sub
</script>

An ArrayList can also be sorted alphabetically or numerically with the Sort() method:

<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New ArrayList
  mycountries.Add("Norway")
  mycountries.Add("Sweden")
  mycountries.Add("France")
  mycountries.Add("Italy")
  mycountries.TrimToSize()
  mycountries.Sort()
end if
end sub
</script>

To sort in reverse order, apply the Reverse() method after the Sort() method:

<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New ArrayList
  mycountries.Add("Norway")
  mycountries.Add("Sweden")
  mycountries.Add("France")
  mycountries.Add("Italy")
  mycountries.TrimToSize()
  mycountries.Sort()
  mycountries.Reverse()
end if
end sub
</script>


Data Binding to an ArrayList

An ArrayList 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" />
</form>

</body>
</html>

Then add the script that builds the list and binds the values in the list to the RadioButtonList control:

Example

<script runat="server">
Sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New ArrayList
  mycountries.Add("Norway")
  mycountries.Add("Sweden")
  mycountries.Add("France")
  mycountries.Add("Italy")
  mycountries.TrimToSize()
  mycountries.Sort()
  rb.DataSource=mycountries
  rb.DataBind()
end if
end sub
</script>

<html>
<body>

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

</body>
</html>

Show example »

The DataSource property of the RadioButtonList control is set to the ArrayList and it defines the data source of the RadioButtonList control. The DataBind() method of the RadioButtonList control binds the data source with the RadioButtonList control.

Note: The data values are used as both the Text and Value properties for the control. To add Values that are different from the Text, use either the Hashtable object or the SortedList object.



WEB HOSTING
Best Web Hosting
PHP MySQL Hosting
Best Hosting Coupons
UK Reseller Hosting
Cloud Hosting
Top Web Hosting
$7.95/mo SEO Hosting
Premium Website Design
WEB BUILDING
Download XML Editor
FREE Website BUILDER
Free Website Templates Free CSS Templates
Make Your Own Website
W3SCHOOLS EXAMS
Get Certified in:
HTML, CSS, JavaScript, XML, PHP, and ASP
W3SCHOOLS BOOKS
New Books:
HTML, CSS
JavaScript, and Ajax
STATISTICS
Browser Statistics
Browser OS
Browser Display
SHARE THIS PAGE