Skip to main content

ASP.NET - The DataList Control


The DataList control is, like the Repeater control, used to display a repeated list of items that are bound to the control. However, the DataList control adds a table around the data items by default.

Bind a DataSet to a DataList Control

The DataList control is, like the Repeater control, used to display a repeated list of items that are bound to the control. However, the DataList control adds a table around the data items by default. The DataList control may be bound to a database table, an XML file, or another list of items. Here we will show how to bind an XML file to a DataList control.
We will use the following XML file in our examples ("cdcatalog.xml"):
<?xml version="1.0" encoding="ISO-8859-1"?>

<catalog>
<cd>
  <title>Empire Burlesque</title>
  <artist>Bob Dylan</artist>
  <country>USA</country>
  <company>Columbia</company>
  <price>10.90</price>
  <year>1985</year>
</cd>
<cd>
  <title>Hide your heart</title>
  <artist>Bonnie Tyler</artist>
  <country>UK</country>
  <company>CBS Records</company>
  <price>9.90</price>
  <year>1988</year>
</cd>
<cd>
  <title>Greatest Hits</title>
  <artist>Dolly Parton</artist>
  <country>USA</country>
  <company>RCA</company>
  <price>9.90</price>
  <year>1982</year>
</cd>
<cd>
  <title>Still got the blues</title>
  <artist>Gary Moore</artist>
  <country>UK</country>
  <company>Virgin records</company>
  <price>10.20</price>
  <year>1990</year>
</cd>
<cd>
  <title>Eros</title>
  <artist>Eros Ramazzotti</artist>
  <country>EU</country>
  <company>BMG</company>
  <price>9.90</price>
  <year>1997</year>
</cd>
</catalog>
Take a look at the XML file: cdcatalog.xml
First, import the "System.Data" namespace. We need this namespace to work with DataSet objects. Include the following directive at the top of an .aspx page:
<%@ Import Namespace="System.Data" %>
Next, create a DataSet for the XML file and load the XML file into the DataSet when the page is first loaded:
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
end if
end sub
Then we create a DataList in an .aspx page. The contents of the <HeaderTemplate> element are rendered first and only once within the output, then the contents of the <ItemTemplate> element are repeated for each "record" in the DataSet, and last, the contents of the <FooterTemplate> element are rendered once within the output:
<html>
<body>

<form runat="server">
<asp:DataList id="cdcatalog" runat="server">

<HeaderTemplate>
...
</HeaderTemplate>

<ItemTemplate>
...
</ItemTemplate>

<FooterTemplate>
...
</FooterTemplate>

</asp:DataList>
</form>

</body>
</html>
Then we add the script that creates the DataSet and binds the mycdcatalog DataSet to the DataList control. We also fill the DataList control with a <HeaderTemplate> that contains the header of the table, an <ItemTemplate> that contains the data items to display, and a <FooterTemplate> that contains a text. Note that the gridlines attribute of the DataList is set to "both" to display table borders:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
  cdcatalog.DataSource=mycdcatalog
  cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:DataList id="cdcatalog"
gridlines="both" runat="server">

<HeaderTemplate>
My CD Catalog
</HeaderTemplate>

<ItemTemplate>
"<%#Container.DataItem("title")%>" of
<%#Container.DataItem("artist")%> -
$<%#Container.DataItem("price")%>
</ItemTemplate>

<FooterTemplate>
Copyright Hege Refsnes
</FooterTemplate>

</asp:DataList>
</form>

</body>
</html>

Show example »

Using Styles

You can also add styles to the DataList control to make the output more fancy:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
  cdcatalog.DataSource=mycdcatalog
  cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:DataList id="cdcatalog"
runat="server"
cellpadding="2"
cellspacing="2"
borderstyle="inset"
backcolor="#e8e8e8"
width="100%"
headerstyle-font-name="Verdana"
headerstyle-font-size="12pt"
headerstyle-horizontalalign="center"
headerstyle-font-bold="true"
itemstyle-backcolor="#778899"
itemstyle-forecolor="#ffffff"
footerstyle-font-size="9pt"
footerstyle-font-italic="true">

<HeaderTemplate>
My CD Catalog
</HeaderTemplate>

<ItemTemplate>
"<%#Container.DataItem("title")%>" of
<%#Container.DataItem("artist")%> -
$<%#Container.DataItem("price")%>
</ItemTemplate>

<FooterTemplate>
Copyright Hege Refsnes
</FooterTemplate>

</asp:DataList>
</form>

</body>
</html>

Show example »

Using the <AlternatingItemTemplate>

You can add an <AlternatingItemTemplate> element after the <ItemTemplate> element to describe the appearance of alternating rows of output. You may style the data in the <AlternatingItemTemplate> section within the DataList control:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
dim mycdcatalog=New DataSet
mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
cdcatalog.DataSource=mycdcatalog
cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:DataList id="cdcatalog"
runat="server"
cellpadding="2"
cellspacing="2"
borderstyle="inset"
backcolor="#e8e8e8"
width="100%"
headerstyle-font-name="Verdana"
headerstyle-font-size="12pt"
headerstyle-horizontalalign="center"
headerstyle-font-bold="True"
itemstyle-backcolor="#778899"
itemstyle-forecolor="#ffffff"
alternatingitemstyle-backcolor="#e8e8e8"
alternatingitemstyle-forecolor="#000000"
footerstyle-font-size="9pt"
footerstyle-font-italic="True">

<HeaderTemplate>
My CD Catalog
</HeaderTemplate>

<ItemTemplate>
"<%#Container.DataItem("title")%>" of
<%#Container.DataItem("artist")%> -
$<%#Container.DataItem("price")%>
</ItemTemplate>

<AlternatingItemTemplate>
"<%#Container.DataItem("title")%>" of
<%#Container.DataItem("artist")%> -
$<%#Container.DataItem("price")%>
</AlternatingItemTemplate>

<FooterTemplate>
&copy; Hege Refsnes
</FooterTemplate>

</asp:DataList>
</form>

</body>
</html>

Show example »

Comments

Popular posts from this blog

Tip/Trick: Fix Common SEO Problems Using the URL Rewrite Extension

Search engine optimization (SEO) is important for any publically facing web-site.  A large % of traffic to sites now comes directly from search engines, and improving your site’s search relevancy will lead to more users visiting your site from search engine queries.  This can directly or indirectly increase the money you make through your site. This blog post covers how you can use the free Microsoft  URL Rewrite Extension  to fix a bunch of common SEO problems that your site might have.  It takes less than 15 minutes (and no code changes) to apply 4 simple  URL Rewrite  rules to your site, and in doing so cause search engines to drive more visitors and traffic to your site.  The techniques below work equally well with both ASP.NET Web Forms and ASP.NET MVC based sites.  They also works with all versions of ASP.NET (and even work with non-ASP.NET content). [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at:  twitter.com/scottg

C# Generic class to parse value - "GenericConverter"

    public class GenericConverter     {         public static T Parse<T>(string sourceValue) where T : IConvertible         {             return (T)Convert.ChangeType(sourceValue, typeof(T));         }         public static T Parse<T>(string sourceValue, IFormatProvider provider) where T : IConvertible         {             return (T)Convert.ChangeType(sourceValue, typeof(T), provider);         }     }     public static class TConverter     {         public static T ChangeType<T>(object value)         {             return (T)ChangeType(typeof(T), value);         }         public static object ChangeType(Type t, object value)         {             TypeConverter tc = TypeDescriptor.GetConverter(t);             return tc.ConvertFrom(value);         }         public static void RegisterTypeConverter<T, TC>() where TC : TypeConverter         {             TypeDescriptor.AddAttributes(typeof(T), new TypeConverterAttribute(typeof(TC)));         }     } ----------------

ASP.NET MVC - Set custom IIdentity or IPrincipal

Here's how I do it. I decided to use IPrincipal instead of IIdentity because it means I don't have to implement both IIdentity and IPrincipal. Create the interface interface ICustomPrincipal : IPrincipal { int UserId { get ; set ; } string FirstName { get ; set ; } string LastName { get ; set ; } } CustomPrincipal public class CustomPrincipal : ICustomPrincipal { public IIdentity Identity { get ; private set ; } public bool IsInRole ( string role ) { return false ; } public CustomPrincipal ( string email ) { this . Identity = new GenericIdentity ( email ); } public int UserId { get ; set ; } public string FirstName { get ; set ; } public string LastName { get ; set ; } } CustomPrincipalSerializeModel - for serializing custom information into userdata field in FormsAuthenticationTicket object. public class CustomPrincipalSerializeMode