ASP.NET Render error

[Brian Begy]

I need to add webcharts dynamically to my page. (Later we are porting to Sharepoint, so everything needs to be added dynamically).

The Render event throws the following error:
[NullReferenceException: Object reference not set to an instance of an object.]
Steema.TeeChart.Web.WebChart.CreatePictureFile(HtmlTextWriter writer)
Steema.TeeChart.Web.WebChart.Render(HtmlTextWriter output)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
System.Web.UI.Control.Render(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)
System.Web.UI.WebControls.TableCell.RenderContents(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
System.Web.UI.Control.Render(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.WebControls.Table.RenderContents(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
System.Web.UI.Control.Render(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer)
System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)
System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)
System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
System.Web.UI.Control.Render(HtmlTextWriter writer)
System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
System.Web.UI.Page.ProcessRequestMain()

Any suggestions? the asp.net userid has permissions on the _chart_temp, so that doesn't seem to be the problem.

[Brian Begy]

I solved it through "voodoo programming" - I changed one variable at a time until it worked.

It turns out, one has to manually populate the myGraph.ID property. I would suggest some enhancement to the error handler to explain what actually went wrong where.

[Pep]

Hi Brian,

thanks for the advise.

It turns out, one has to manually populate the myGraph.ID property. I would suggest some enhancement to the error handler to explain what actually went wrong where.

Ok, I've added this comment on our wish list to see what can we do.

[Brian Begy]

Jose,

It seems that this particular issue is unlikely to occur very often, but in general, the error messages should provide some guidance to developers.