How to get around storing a usercontrol out of process in session state

Question

I am attempting to store a usercontrol in session state between postbacks, using SQL as stateserver.

I get the class not serializable error:

Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.

Stack Trace

SerializationException: Type 'ASP.bookingcontrols_controls_ucDates_ascx' in Assembly 'App_Web_eckjngpu, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' is not marked as serializable.]

Now, marking the usercontorl class as Serializable, I still get this error. From research I have determined, thus far, that a usercontrol cannot be serialized. Fine.

The general proposed idea to get around this, seems to be to split control (data) from the control (interface/front end), and rebuild it on the other side.

Now, before I attempt to make some impacting changes to my code, my question is the following:

Will an object derived from the usercontrol class, but not created as a dynamic usercontrol by means of page.loadcontrol("control.ascx"), be serializable, or do I have to create a seperate "accompanying class" to store the data. If so, I assume I can not inherit from the control class to get the properties, as it will ultimately inherit the usercontrol classes that are not serializable?

Example:

Not using:

Dim myDatesControl As New UserControl
myDatesControl = Page.LoadControl("~/bookingControls/ucDates.ascx")

        With CType(myDatesControl, controls_ucDates)
            .checkInDate = Session("nowcheckin")
            .checkOutDate = Session("nowcheckout")
            .Nights = "xxx"
            .guid = currentBookingFilter.guid
            .ExtraInfo = currentBookingFilter
        End With

Would the following work, as an object that would be serializable to out of process session state.

Dim myDatesControl As New controls_ucDates

        With CType(myDatesControl, controls_ucDates)
            .checkInDate = Session("nowcheckin")
            .checkOutDate = Session("nowcheckout")
            .Nights = "xxx"
            .guid = currentBookingFilter.guid
            .ExtraInfo = currentBookingFilter
        End With

In the second block, would myDatesControl be serializable?

Answer 1

nThe end result was that the myDatesContorl class, inheriting from usercontrol class, could not be serialized to session state.

I created a "accompanying" class and duplicated the properties of the UC. In my code, I then use the accompanying class to store state about the control, and create the controls only before display, re-reassign their properties.