I've been working on a templated control, and I'm astounded at how slow it is. I looked at the execution times and narrowed it down to the actual data binding of a particular item...

TemplateItem item = new TemplateItem();
item.DataItem = simpleContainerClass;
ITemplate template;
if (_postTemplate != null)
{
    template = _postTemplate;
    template.InstantiateIn(item);
    this.Controls.Add(item);
}
item.DataBind();

This block of code runs once for each item in the collection of data items in the control's CreatChildControls() method. The TemplateItem class is just a container class with one property called DataItem. The last line, the DataBind() method, takes nearly .1 seconds for each item. That's obviously not acceptable.

Am I missing something here or is there just something slow about using this? I'm using v2 of .NET, by the way.

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Jeff "Jones" Putz
Go from beginner to guru: Maximizing ASP.NET
uber:ASP.Net

When you call DataBind() on the item, any databinding expressions that exist in the template are executed. For example, in this expression:
   <%# Eval("Name") %>
The Eval() method will be called. This uses Reflection to evaluate the "Name" property of the current data item. Although you might be thinking that Reflection is slow, believe me, it's not *that* slow! :)

However, if the "getter" of the "Name" property is very slow, that might be the cause of the overall slowness. For example, if it goes to a database every time you get the value of the property, that would very well explain it.

Can you take a look at what the contents of the template are and perhaps what exactly is being databound in there?

Thanks,
Eilon

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Blog: http://weblogs.asp.net/LeftSlipper/