Question

I am sure everyone who programmed with user controls for asp.net came across situations where you needed a certain way to check whether a user control has been loaded for the first time or it has been re-loaded. Has anyone come up with any other solutions other than setting hidden “currentOpenControl” flag(s). If you are wondering as to do I need to check whether control is open for first time or re-open again, then one of the big reasons is databinding. When the control is open for first time, that is when I want to databind, afterwards on re-open, if I databind again I will lose any changes user might have added.
So I am just wondering if anyone has a more elegant solution than setting flags whether control is open or not.

Thanks

Answer 1

The only way I’ve ever managed to do this is by using the ViewState…

Private Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
  If ViewState["postBack"] Is Nothing Then
    ' Do everything you'd normally do with Page.IsPostBack
    ViewState["postBack"] = true
  End 
End Sub

Or for C#…

protected void Page_Load(object sender, EventArgs e)
{
  if (ViewState["postBack"] == null)
  {
    // Do everything you'd normally do with Page.IsPostBack
    ViewState["postBack"] = true;
  }
}