Use the ParseChildrenAttribute and PersistChildrenAttribute attributes:
[ParseChildren(false)]
[PersistChildren(true)]
public class MyControl : UserControl { }
This will cause any controls you put inside the reference:
<uc:MyControl runat="server">
<asp:TextBox runat="server" />
<uc:MyControl>
To be appended to the end of the Controls collection of your UserControl contents.
However, if you want to have a collection of controls, you should probably use a server control and not a user control. For a control that works like this:
<foo:TabControl runat="server">
<Tabs>
<foo:Tab CssClass="myclass" Title="Hello World" />
</Tabs>
</foo:TabControl>
You need a Control class that has a Tabs property; the Tabs property should be a Collection; and it should contain objects of type Tab. I've created the three classes here:
[ParseChildren(true, "Tabs")]
public class TabControl: WebControl, INamingContainer
{
private TabCollection _tabs;
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
[PersistenceMode(PersistenceMode.InnerDefaultProperty)]
public TabCollection Tabs
{
get
{
if (_tabs == null)
{
_tabs = new TabCollection();
}
return _tabs;
}
}
protected override void Render(HtmlTextWriter writer)
{
foreach (Tab tab in Tabs)
{
writer.WriteBeginTag("div");
writer.WriteAttribute("class", tab.CssClass);
writer.Write(HtmlTextWriter.TagRightChar);
writer.Write("this is a tab called " + tab.Title);
writer.WriteEndTag("div");
}
}
}
And the tab class:
public class Tab
{
public string CssClass { get; set; }
public string Title { get; set; }
}
And the tab collection:
public class TabCollection : Collection<Tab> { }
