I tripped over a seriously annoying thing in ASP.NET late yesterday, and continued tripping much of this morning. I had a user control that contained a repeater. On initial load of the control, I did my DataBind() protected by an !IsPostBack. I didn’t disable ViewState (though it grates on me to leave that bloated beast in place). Everything rendered like you’d expect.
Then the postback came, my repeater’s Items were empty.
I beat my head against this. I validated my repeater wrote to ViewState. I changed where I was data binding. I debugged into the Framework code, but never managed found why I wasn’t getting my controls created again.
To make sure I wasn’t crazy, I pulled the Repeater to the page, out of my user control, and everything worked as expected–Repeater.Items was present on the postback.
I mentioned the struggle in stand-up, and a coworker kindly showed me the solution:
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
EnsureChildControls();
}
Bing. Suddenly all of my repeater controls were there when I looked for them.
Why there’s this difference between repeaters in a Page or UserControl, I don’t know, but it did the trick.