Question

I’m having some issues trying to keep the state of values in textbox controls between postbacks in a wizard that is part of a user-control (.ascx) file.

Some background

This is an order form for a product that can have different options (1 product can have many options), so the options are not generic.
A list of options (pulled from the database using SubSonic 2) is displayed to the user in the ‘start’ stage of the wizard for the selected product, using the syntax “OptionBox-4” (with the number on the end being the ID of the option in the database so i can go back later and grab the description.

The user can then enter different quantities in each of the options.

The problem

Once the user has entered the quantities in the boxes, and hit ‘next’ the Values are not being stored between postbacks, or the ID’s of the controls.

The code

<asp:Wizard ID="Wizard1" runat="server" ActiveStepIndex="0"
    DisplaySideBar="False" onnextbuttonclick="Wizard1_NextButtonClick" 
    onpreviousbuttonclick="Wizard1_PreviousButtonClick" 
    FinishCompleteButtonText="Submit request"  
    onfinishbuttonclick="Wizard1_FinishButtonClick" 
    onactivestepchanged="Wizard1_ActiveStepChanged" 
    onprerender="Wizard1_PreRender" >
    <FinishPreviousButtonStyle CssClass="subbutton" />
    <FinishCompleteButtonStyle CssClass="subbutton" />
    <StartNextButtonStyle CssClass="subbutton" />
    <StepNextButtonStyle CssClass="subbutton" />
    <StepPreviousButtonStyle CssClass="subbutton" />
    <WizardSteps>
        <asp:WizardStep runat="server" StepType="Start" title="Description" ID="vgStep1">
            <fieldset class="emailform">
            <ul runat="server" id="optionList">
                <asp:PlaceHolder id="DynamicBoxes" runat="server" />
            </ul>
            </fieldset>
        </asp:WizardStep>
        <asp:WizardStep ID="WizardStep1" runat="server" Title="Your details" StepType="Finish">
            <h3>Order summary</h3>
            <asp:Literal ID="ltlSummary" runat="server"></asp:Literal>
        </asp:WizardStep>
        <asp:WizardStep ID="WizardStep2" runat="server" StepType="Complete" Title="Thank you">

        </asp:WizardStep>
    </WizardSteps>
</asp:Wizard>

the relevant codebehind

    class ResponseCollection : List<string> { }
private int? NrOfOptions
{
    get { return (int?)ViewState["NrOfOptions"]; }
    set { ViewState["NrOfOptions"] = value; }
}
public PartnerProductOrderableOptionCollection colOptions;
public PartnerProductOrderable prodOrderable;

protected void Page_Load(object sender, EventArgs e)
{
    LoadOrderWizard(Utility.GetPartnerProductId(Request.QueryString["ppid"]));
    CreateDynamicBoxes();
}

#region Ordering wizard
private void LoadOrderWizard(int p)
{

    partnerProduct = new PartnerProduct(p);

    prodOrderable = new PartnerProductOrderable("PartnerProductId", p);

    colOptions = new PartnerProductOrderableOptionCollection();
    colOptions.LoadAndCloseReader(PartnerProductOrderableOption.FetchByParameter("OrderableId", prodOrderable.OrderableId, OrderBy.Asc("ListOrder")));
    if (!IsPostBack)
    {
        this.NrOfOptions = colOptions.Count;
    }
}

protected void Wizard1_ActiveStepChanged(object sender, EventArgs e)
{
    if (Wizard1.ActiveStepIndex == 1)
    {
        ResponseCollection responses = CollectValuesFromDynamicBoxes();
        ltlSummary.Text += "Controls:";
        foreach (Control c in DynamicBoxes.Controls)
        {
            ltlSummary.Text += c.ID + ",";
            if (c is TextBox)
            {
                ltlSummary.Text += ((TextBox)c).ID + ",";
                if (!String.IsNullOrEmpty(((TextBox)c).Text))
                {
                    int optionid = int.Parse(c.ID.Split('-')[1]);
                    PartnerProductOrderableOption o = new PartnerProductOrderableOption(optionid);
                    ltlSummary.Text += "<strong>Quantity: </strong>" + ((TextBox)c).Text + "<br />";
                    ltlSummary.Text += "<strong>Description: </strong>" + o.Description + " - " + o.Price + "<hr />";

                }
            }
        }
    }
}

protected void Wizard1_PreviousButtonClick(object sender, WizardNavigationEventArgs e)
{
}

protected void Wizard1_FinishButtonClick(object sender, WizardNavigationEventArgs e)
{
    ResponseCollection responses = CollectValuesFromDynamicBoxes();
}
protected void Wizard1_NextButtonClick(object sender, WizardNavigationEventArgs e)
{
    if (e.CurrentStepIndex == 0)
    {
        int newNumberOfOptions = colOptions.Count;
        int? oldNumberOfOptions = this.NrOfOptions;


        if (!oldNumberOfOptions.HasValue || newNumberOfOptions != oldNumberOfOptions.Value)
        {
            this.NrOfOptions = newNumberOfOptions;

            CreateDynamicBoxes();
        }
    }
}
private void CreateDynamicBoxes()
{
    if (!this.NrOfOptions.HasValue)
        return;

    DynamicBoxes.Controls.Clear();

    foreach (PartnerProductOrderableOption opt in colOptions)
    {
        HtmlGenericControl li = new HtmlGenericControl("li");
        DynamicBoxes.Controls.Add(li);

        TextBox box = new TextBox();
        box.ID = "OptionBox-" + opt.OptionId;
        box.Width = 40;
        box.MaxLength = 6;

        li.Controls.Add(box);

        Label lblOpt = new Label();
        lblOpt.ID = "lblOption-" + opt.OptionId;
        lblOpt.Text = opt.Description + " - " + opt.Price;
        li.Controls.Add(lblOpt);
    }
    this.NrOfOptions= colOptions.Count;
}

private ResponseCollection CollectValuesFromDynamicBoxes()
{
    ResponseCollection responses = new ResponseCollection();
    for (int i = 0; i < this.NrOfOptions.Value; i++)
    {
        TextBox box = (TextBox)DynamicBoxes.FindControl("OptionBox-" + i);
        string response = box.Text.Trim();

        if (response.Length > 0)
            responses.Add(response);
    }
    return responses;
}


protected void Wizard1_PreRender(object sender, EventArgs e)
{

}

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);

}

#endregion

The code is loosely based on http://aspnetresources.com/blog/dynamic_text_bBoxes_in_wizard_control which seems to do something very similar to what i need mine to do.

Another note

the LoadOrderWizard method has to be called in the Page_Load event. This is a stripped down code with only the code relevant to my issue shown. The control actually consists of a few different panels that display different information based on data passed to the control. therefore having initialisation code in the Page_Init event would fire un-necessarily.

Answer 1

In the end, because i couldn’t find a workable solution to this, I have ended up using a session variable to store the id of the dynamic box and the value contained. I then on other pages check to see if the textbox id is contained within the session, and restore it’s value to the box.

As only numbers get put in this box, this solution is a workaround for me. However it would still be nice to know if there is another solution.