I have a small classic asp.net app, and I have a GridView that is hidden:
<asp:GridView ID="grid1" runat="server" Visible="false" AutoGenerateColumns="true"></asp:GridView>
On initialization in the codebehind, I populate the GridView and I'm happy!
But, when there's a PostBack, its immediately empty.
I know in other apps I have it persists on PostBack, but not in this one. I'm sure I'm forgetting something.
I don't have a method which clears the data - that would be silly. (But I'll double check).