Click here to Skip to main content
65,938 articles
CodeProject is changing. Read more.
Articles
(untagged)

A quick guide to using nested repeaters in ASP.NET

0.00/5 (No votes)
19 Feb 2004 1  
Using nested repeaters in ASP.NET with an XML data store

Introduction

I've never really been much of a web-developer and never thought I'd find web-development all that interesting. But I must say I've been quite fascinated by what little ASP.NET I've done up till now, which is not a lot to be honest. One control I found particularly useful was the Repeater control, but I struggled a little when I tried to implement nested repeaters using an XML file as the data store. Eventually, the solution turned out to be embarrassingly easy, and I thought I'd write a little article for other first-timers who might encounter the same annoying situation I did.

Note to readers

I assume that you already know how to use a Repeater control. This article only shows you how to implement nested repeaters and will not attempt to explain repeaters in general.

Example

I am going to demonstrate a simple ASP.NET web application that will list out a Cricket World XI using an XML file as the input-data. Eventually, modification of the team simply involves a change in the XML file with no changes required either in the aspx pages or in the code-behind files.

My XML file

Essentially I have four categories - and each category has one or more players.

Implementing nested repeaters

I am going to list the categories first and inside each category I will list the players under that category. Lets first add the outter repeater that will list the categories.

We now add the inner repeater to the <ItemTemplate> tag of the outter repeater.

Writing the code-behind code

Alright, I know that "code-behind code" sounds weird, but I couldn't think of anything better sounding and if anyone has any better ideas, please drop me a line. Anyway we setup the first repeater in the Page_Load event handler as usual.

private void Page_Load(object sender, System.EventArgs e)
{
    DataSet ds = new DataSet();
    ds.ReadXml(MapPath("./XMLFile1.xml"));
    CategoryRepeater.DataSource = ds;
    CategoryRepeater.DataBind();
}

For setting up the outter repeater, we handle the ItemDataBound event of the Repeater class which is raised when an item is data-bound but before it is rendered on the page. We now get a reference to the PlayerRepeater control using RepeaterItem.FindControl and set its data source using CreateChildView and the automatic relation that's made for us - category_cricketer. By the way I was quite impressed by that, I never expected automatic relations to be created based on the XML. Pretty cool I think!

private void CategoryRepeater_ItemDataBound(object sender, 
    System.Web.UI.WebControls.RepeaterItemEventArgs e)
{
    RepeaterItem item = e.Item;
    if( (item.ItemType == ListItemType.Item) ||
        (item.ItemType == ListItemType.AlternatingItem) )
    {
        PlayerRepeater = (Repeater) item.FindControl("PlayerRepeater");
        DataRowView drv = (DataRowView)item.DataItem;
        PlayerRepeater.DataSource = drv.CreateChildView("category_cricketer");
        PlayerRepeater.DataBind();
    }
}

That's all.

The output

I got the below output when I viewed the web-form in my browser.

Conclusion

Feedback and criticism is welcome as usual. I'd also like to thank Aravind Corera (Chennai based C# MVP) who gave me the right URLs to solve this problem when I was tearing my hair out in frustration.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here