Dynamically Loading Custom User Control and Storing in Session...

Question

User1823070883 posted

Hi all I have a usercontrol that has lots of form elements in it, textboxes, drop downs etc and two buttons - Save and Cancel. I am loading this usercontrol dynimically in the aspx's code behind like so in the pages PreLoad even (I have also tried; Init; PreInit and Load:

ProtocolDeviationForm = Page.LoadControl("~/Secure/GlobalUserControls/ProtocolDeviationForm.ascx") 

If Not (Session("ProtocolDeviationForm") Is Nothing) Then 

ProtocolDeviationForm = TryCast(Session("ProtocolDeviationForm"), ProtocolDeviationForm) 

End If 

ProtocolDeviationForm.ID = "ProtocolDeviationForm" 

AddHandler ProtocolDeviationForm.UpdateProtocolDeviation, AddressOf UpdateProtocolDevaition 

AddHandler ProtocolDeviationForm.CancelProtocolDeviation, AddressOf CancelProtocolDevaition 

AddHandler ProtocolDeviationForm.SaveProtocolDeviation, AddressOf SaveProtocolDevaition 

plcProtocolDeviationForm.Controls.Add(ProtocolDeviationForm)

As you can see I am also storing the User Control in Session so that what properties have been assigned to it are stored. I am doing this like so:

ProtocolDeviationForm = LoadControl("~/Secure/GlobalUserControls/ProtocolDeviationForm.ascx") 
ProtocolDeviationForm.ID = "ProtocolDeviationForm"
 ProtocolDeviationForm.CilCode = cilCode
 ProtocolDeviationForm.StudyLevelId = Request.QueryString("subjectId")
 ProtocolDeviationForm.StudyLevel = StudyLevel.Subject 
ProtocolDeviationForm.ProtocolDeviationId = CType(e.CommandArgument, Integer) 
ProtocolDeviationForm.FormAction = FormAction.Add 
Session("ProtocolDeviationForm") = ProtocolDeviationForm
 plcProtocolDeviationForm.Controls.Add(ProtocolDeviationForm)

However, when the button in the user control is clicked... two things happen depending on what is included in the first snippet of code:

If the following isn't included -

If Not (Session("ProtocolDeviationForm") Is Nothing) Then
 ProtocolDeviationForm = TryCast(Session("ProtocolDeviationForm"), ProtocolDeviationForm)
 End If

The event for the button in the usercontrol is fired but the User Control properties are all blank (default values). However, if I include this line, the event for the button doesn't fire but the Control seems to be loaded from Session.

I am really stumped and have been working on this for a couple of days now...

Does anyone know what the problem is? Thanks in advance

Mark

Answer 1

User3866881 posted

Hello:)

Have you tried to load the control in the “If Not IsPostBaclk……End If” block in the Page_Load.

And how did you write your user control?

Plz show us your full codes...

Thx very much

Answer 2

User1823070883 posted

Hi - thanks for your reply!

The problem is is that the usercontrol is loaded when a button is clicked.

Mark

Answer 3

User3866881 posted

The problem is is that the usercontrol is loaded when a button is clicked.

So you mean you don't want the usercontrol to load when you click the button?

Answer 4

User1823070883 posted

No I want it to load when the button is clicked.  The problem would be if I put If Not Is Postback... as the button is a post back... therefore the UserControl won't load from Session nor will the events in the control be wired up!

Answer 5

User3866881 posted

The event for the button in the usercontrol is fired but the User Control properties are all blank (default values).

Hello again:)

Please make sure that your self-made propeties like Id or CilCode...,ect. are something stored in the ViewState instead of losting data contents:

public int ID

{

    get

    {

        ViewState["id"]==null?0:(int)ViewState["id"];

    }

    set

     {

           ViewState["id"] = value;

     }

}

You CANNOT define the property like:

public int Id{get;set;}

For everytime when the control is created and load, this property value will be recreate again with the newly-built control and all the previous data contents will be lost.