Add Chart in TableCell Render Method

[Volker Weg]

I have an WebControl witch renders an asptable:

public class Def : WebControl
{


protected override void Render(HtmlTextWriter output)
        {
            WriteReportToAspTable();
            repTable.RenderControl(output);
        }
//....
}

I add an TableRow to the table an then ...

The Table uses an Custom Object inherited from TableCell:
repTableRow.Cells.Add(MyCustomTableCellInheritedFromTableCell)

The MyTableCell has the overriden TableCell -Rendermethod:

public class XpsTableCell : System.Web.UI.WebControls.TableCell
{
//....
protected override void RenderContents(HtmlTextWriter writer)
        {
            base.RenderContents(writer);
        }
//....
}
When I try now to add an Chart to the MyTableCell I get an error:
repTableRowCell.Controls.Add(Chart); // Where Chart is the Telerik Chart

Error:
System.NullReferenceException:
   bei Telerik.WebControls.RadChart.RenderContents(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.TableCell.RenderContents(HtmlTextWriter writer)
   bei XPS.Controls.rep.XpsTableCell.RenderContents(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.Table.RenderContents(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei XPS.Controls.rep.Def.Render(HtmlTextWriter output)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.Control.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.Control.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei ASP.tools_controls_comprisikoanalyse_ascx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in ---cut----s\CompRisikoanalyse.ascx:Zeile 22.
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.Control.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)
   bei System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)
   bei System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.Page.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei Telerik.WebControls.RadAjaxManager.AJAX_Page_Render(HtmlTextWriter output, Control container)
   bei System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   bei System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   bei System.Web.UI.Page.Render(HtmlTextWriter writer)
   bei System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   bei System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   bei System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Does anyone can help me on how to add an Control to an inherited Control like the TableCell?
I think I have to add the Control to the Writer and not to the Tablecell via
MyCell.Controls.Add(...)

Any Suggestion?

Regards,

[Ves]

Hi Volker,

Please, open a formal support ticket and attach a small runnable demo project there. Once we run it locally, we will investigate it and get back to you with our findings.

Regards,
Ves
the Telerik team

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