Chart with Annotation objects causes Exceptions during Rendering

[paulgrn]

I'm using VB.Net in Visual Studio 2005.  I'm using ChartFX.Internet version 6.2.1342.0 (runtime version v1.0.3705). The ChartFX.Annotation library I'm using shows the same version numbers.

I have a page that contains four SoftwareFX.ChartFX.Internet.Server.Chart objects dynamically generated every time during the Page_Load event.  One of these chart objects hosts a SoftwareFX.ChartFX.Annotation.AnnotationX object which hosts a collection of AnnotationText and AnnotationArrow objects.  No other data is loaded on this chart.

When the page is first loaded, all four charts load and render just fine.  Post backs typically works fine as well.  However, I have an .ascx file which hosts a panel containing standard asp:TextBox, asp:ImageButton, asp:Panel, and asp:Calendar controls which are used to select a start or end date for my date range.  When the ImageButton containing the picture of a calendar is pressed, a postback occurs which loads the charts and then processes the imagebutton click to make the asp:Calendar control visible.  From there, the standard rendering mechanism kicks in to generate the page and send it to the client.  However, during the rendering, the chart hosting the annotation objects throws an exception.  I get this exception:

at SoftwareFX.ChartFX.Internet.Server.AxisBase.FF(1N 1LZ, Rectangle[] 1M0, SetPropFlag& 1M1, 15 1M2, AxisSection& 1M3)

at SoftwareFX.ChartFX.Internet.Server.AxisCollection.FZ(1N 1N6, Rectangle[] 1N7, 15 1N8)

at SoftwareFX.ChartFX.Internet.Server.ChartCore.5I(1N 0ZW, Boolean 0ZX, Boolean 0ZY)

at SoftwareFX.ChartFX.Internet.Server.ChartCore.5H(1N 0ZT, Rectangle& 0ZU, Int32& 0ZV)

at SoftwareFX.ChartFX.Internet.Server.ChartCore.5G(PaintBar 0ZQ, IGraphicsEx 0ZR, Rectangle& 0ZS)

at SoftwareFX.ChartFX.Internet.Server.ChartCore.7B(PaintBar 12L, IGraphicsEx 12M, Rectangle& 12N)

at SoftwareFX.ChartFX.Internet.Server.Chart.80(Stream 13Y, IOutputWriter 13Z, OutputText 140, OutputText 141, OutputInfo& 142)

at SoftwareFX.ChartFX.Internet.Server.Chart.8G(OutputText 14W, OutputText 14X, Boolean 14Y, Boolean 14Z, String 150)

at SoftwareFX.ChartFX.Internet.Server.Chart.Render(HtmlTextWriter output)

at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)

.... (more render / render control / renderchildren / render children internal lines ommitted for brevity)

at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)

at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)

at System.Web.UI.Control.Render(HtmlTextWriter writer)

at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)

at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)

at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)

at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)

at System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)

at System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output)

at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer)

at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)

at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)

at System.Web.UI.Page.Render(HtmlTextWriter writer)

at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)

at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

The Exception.Message is "Object reference not set to an instance of an object."  The Exception.Source is "ChartFX.Internet".

Commenting out the code to add the one chart containing the annotation objects causes the problem to go away. 

 Any ideas or suggestions?

 

[paulgrn]

Well, I didn't figure out what the cause is but I did find that if I reload the chart with data after handling the calendar control's event, that I can prevent the problem from occurring.  I'm good with this workaround.