URL's not being resolved when in UserControl (ASP.NET)

Question

If I pass the derived class testA a PlaceHolder that contains a Hyperlink, with a url that starts with a tilde, it resolves it correctly. However, when I pass testB (identical apart from it inherits from System.Web.UI.UserControl) the same PlaceHolder It renders it literally (doesn't transform / resolve the '~')

Any ideas?

public class testA : System.Web.UI.Control
{
    public System.Web.UI.WebControls.PlaceHolder plc { get; set; }
    protected override void OnLoad(EventArgs e)
    {
        if (plc != null)
            this.Controls.Add(plc);
        base.OnLoad(e);
    }
}


public class testB : System.Web.UI.UserControl
{
    public System.Web.UI.WebControls.PlaceHolder plc { get; set; }
    protected override void OnLoad(EventArgs e)
    {
        if (plc != null)
            this.Controls.Add(plc);
        base.OnLoad(e);
    }
}

This is ASP.NET

Answer 1

When you inherit from System.Web.UI.UserControl and do not associate your control with an ascx file then your control TemplateSourceVirtualDirectory will not be set, this is required by the ResolveClientUrl method - if its null or empty the url will be returned AS IS.

To solve your problem, just set AppRelativeTemplateSourceDirectory :

public class testB : System.Web.UI.UserControl
{
    public System.Web.UI.WebControls.PlaceHolder plc { get; set; }
    protected override void OnLoad(EventArgs e)
    {
        if (plc != null)
        {
            this.AppRelativeTemplateSourceDirectory =
                    plc.AppRelativeTemplateSourceDirectory;
            this.Controls.Add(plc);
        }
        base.OnLoad(e);
    }
}