Composite Control with DropDownList loses items after Postback

Question

User2111504239 posted

Hi,

I'm creating a composite control which should be called from aspx/ascx like the following:

<ws:ExtendedLabel ID="lab_name" Text="Name" PopupText="Enter your name here" runat="server"
            IsMandatory="true">
               <asp:TextBox ID="tb_name" runat="server" Text="" />
</ws:ExtendedLabel>

So, the Label should be rendered, together with an mandatory-sign and small tooltip popping up when mouseover is active. Additionally, the TextBox should be associated to the label and rendered.

For that I created a UserControl, derived from Label. I use the [ParseChildren(false)]-Property.

In CreateChildControls() I add the Link for the tooltip-layer and the tooltip itself. I also override the RenderChildren-function to add some html before/after rendering the textbox.

This works fine, even after Postback everything works as espected.

If I want to use a DropDownList instead of a TextBox, the DropDownList loses their items. After some websearch I think this is a viewstate-problem, but I don't know how to solve it.

Any help?

I tried to describe the problem and didn't posted the complete source-code to leave this post slim.

Cheers, kalle.