Property null after postback - Dynamically loaded control

Question

I\'m aware this question has been asked many times before but I suspect I have a unique scenario.

I\'m loading a Child Control (ASCX) and setting a Property on that

Answer 1

In Microsoft explanations about ASP.NET page life cycle, it is written that dynamically created controls must be created in PreInit.

It worked for me. Here is my main page :

protected global::System.Web.UI.HtmlControls.HtmlGenericControl FiltersZone;

(. . .)

 protected override void OnPreInit(EventArgs e)
    {
        base.OnPreInit(e);
        FiltersZone.Controls.Add(new PlanningFiltersSurgeonWeb());
    }

This dynamically created ".ascx" control contains an hidden field :

I am now able to retrieve its value from within dynamically created ASCX control Page_Load event, after a "submit" or a "__dopostback('hidTxtPaint')" initiated from JavaScript.

On the other hand, the hidden field's value is always empty after a POST if its parent ".ascx" control is added in main page's Page_Load event.