I have a custom user control ascx that exposes a simple property
/// <summary>
/// The currently selected ID, if there is one
/// </summary>
public virtual int? SelectedId
{
get { return (int)ViewState["XXID"]; }
set { ViewState["XXID"] = value; }
}
The control is inside a PlaceHolder and the value reads just fine in the postback onclick method of a button below the PlaceHolder.
However if the PlaceHolder visible=false then ViewState["XXID"] returns null. If I toggle the PlaceHolder visible=true then the value comes back.
<asp:PlaceHolder runat="server" ID="plcCustomer" >
<my:CustomPicker runat="server" ID="cboCustomer" />
</asp:PlaceHolder >
<asp:Button runat="server" ID="btnToggleVisible" onclick="btnToggleVisible_OnClick" text="Toggle visible" />
<asp:Button runat="server" ID="btnGetSelectedId" onclick="btnGetSelectedId_OnClick" text="Get Value" />
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
plcCustomer.SelectedId = 5;
}
protected void btnToggleVisible_OnClick(object sender, EventArgs e)
{
plcCustomer.Visible = !plcCustomer.Visible;
}
protected void btnGetSelectedId_OnClick(object sender, EventArgs e)
{
...
plcCustomer.SelectedId //<== this will be null whenever plcCustomer is invisible
...
}
I have a hunch that the page has not bothered loading my control's viewstate because it is not going to be visible.
If so how can I instruct the page that it should load the viewstate of custom controls even when they are in a hidden PlaceHolder?
