DynamicControl with custom bound attribute

Question

I'm working with webforms and dynamic data and need to pass an object from the code behind my dynamic controls to my field template.

I have successfully tried this using a string property called Test. To demonstrate, this control is on my form...

<asp:DynamicControl Test="Hello field" id="MyID" runat="server" DataField="MyField" Mode="Edit" />

... where MyField is a string property of the bound object, and my String_Edit.ascx field template has the following property...

public string Test { get; set; }

... I can see that this property Test holds the value I supplied i.e. "Hello field" when I break at its Page_Load method.

What I actually want though is to pass a more complex object which is referenced as a property in my code behind. But if I try this...

<asp:DynamicControl Test="<%# this.MyObject %>" id="MyID" runat="server" DataField="MyField" Mode="Edit" />

... where the code-behind has this property...

    protected MyClass MyObject
    {
        get
        {
            if (this.o == null)
            {
                this.o = new MyClass();
            }

            return this.o;
        }
    }

... and my String_Edit.ascx has its property changed to...

public MyClass Test { get; set; }

... then this property Test is always null.

I have a feeling that the problem is something to do with having to binding the control, but when I try this I get exceptions along the lines of "Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control".

Update

I've since found that even the following code...

<asp:DynamicControl Test="<%# Eval("MyProperty") %>" id="MyID" runat="server" DataField="MyField" Mode="Edit" />

...where MyProperty is a string property of the bound object, even that doesn't end up populating the Test property of String_Edit.ascx. Even though when I debug I can see MyProperty being accessed.

Any suggestions most welcome.

Answer 1

this is not possible you can only pass in "value types" via the markup. note this is not a limitation of Dynamic Data but Asp.Net WebForms sorry.