Object Reference Not Set When Placing Chart on Form

[Hamish Gunn]

I received this message when I try to compile. My chart became a box with a red border and a trace message inside ("System.NullReferenceException..."). Somehow or other I managed to get this to run and the chart appeared at run time.

Now however the chart appears at design time but my program appears to compile but I get the message Object Reference Not Set when the form tries to load.
The Stack Trace starts
StackTrace " at Syncfusion.Windows.Forms.Chart.ChartLegend.AutoSize(Rectangle rect)
at Syncfusion.Windows.Forms.Chart.ChartLegend.AutoLocation(Rectangle rect)
at Syncfusion.Windows.Forms.Chart.ChartControl.RecalculateSizes()
at Syncfusion.Windows.Forms.Chart.ChartLegend.OnRecalculateSizes()
at Syncfusion.Windows.Forms.Chart.ChartLegend.OnLegentSizeChange()
at Syncfusion.Windows.Forms.Chart.ChartLegend.set_CustomItems(LegendItem[] value)

This seems to be a legend problem. I''ve re-installed Syncfusion and Studio but still have the problem. I can''t keep replacing the Chart on the form as it is too time consuming.

[Hamish Gunn]

The problem appears to be that the Chart Designer is not creating the Legend. The error occurs at the line which Adds a Legend. The parameter is a ChartLegend object:

''
''chrtOutput
''
Me.chrtOutput.BackColor = System.Drawing.Color.White
Me.chrtOutput.Controls.Add(Me.chrtOutput.Legend)
...

- Me.chrtOutput.Legend {Syncfusion.Windows.Forms.Chart.ChartLegend} Syncfusion.Windows.Forms.Chart.ChartLegend
+ AccessibilityObject {System.Windows.Forms.Control.ControlAccessibleObject} System.Windows.Forms.AccessibleObject
AccessibleDefaultActionDescription Nothing String
AccessibleDescription Nothing String
AccessibleName Nothing String
AccessibleRole Default System.Windows.Forms.AccessibleRole
AllowDrop False Boolean
Anchor 9 System.Windows.Forms.AnchorStyles
+ BackColor {System.Drawing.Color} System.Drawing.Color
BackgroundImage Nothing System.Drawing.Image
BindingContext Nothing System.Windows.Forms.BindingContext
+ Border {Syncfusion.Windows.Forms.Chart.LineInfo} Syncfusion.Windows.Forms.Chart.LineInfo
Bottom 48 Integer
+ Bounds {System.Drawing.Rectangle} System.Drawing.Rectangle
CanFocus False Boolean
CanSelect True Boolean
Capture False Boolean
CausesValidation True Boolean
+ ClientRectangle {System.Drawing.Rectangle} System.Drawing.Rectangle
+ ClientSize {System.Drawing.Size} System.Drawing.Size
Columns 1 Integer
CompanyName "Syncfusion, Inc." String
Container Nothing System.ComponentModel.IContainer
ContainsFocus False Boolean
ContextMenu Nothing System.Windows.Forms.ContextMenu
+ Controls {System.Windows.Forms.Control.ControlCollection} System.Windows.Forms.Control.ControlCollection
Created True Boolean
+ Cursor {System.Windows.Forms.Cursor} System.Windows.Forms.Cursor
CustomItems {Length=0} Syncfusion.Windows.Forms.Chart.LegendItem()
+ DataBindings {System.Windows.Forms.ControlBindingsCollection} System.Windows.Forms.ControlBindingsCollection
+ DefaultBackColor {System.Drawing.Color} System.Drawing.Color
+ DefaultFont {System.Drawing.Font} System.Drawing.Font
+ DefaultForeColor {System.Drawing.Color} System.Drawing.Color
+ DisplayRectangle {System.Drawing.Rectangle} System.Drawing.Rectangle
Disposing False Boolean
Dock None System.Windows.Forms.DockStyle
Enabled True Boolean
FloatingAutoSize True Boolean
Focused False Boolean
+ Font {System.Drawing.Font} System.Drawing.Font
+ ForeColor {System.Drawing.Color} System.Drawing.Color
Handle 2035040 System.IntPtr
HasChildren False Boolean
Height 28 Integer
ImeMode NoControl System.Windows.Forms.ImeMode
InvokeRequired False Boolean
IsAccessible False Boolean
IsDisposed False Boolean
IsHandleCreated True Boolean
ItemsAlignment Near System.Drawing.StringAlignment
Left 162 Integer
LegendAlignment Center System.Drawing.StringAlignment
+ Location {System.Drawing.Point} System.Drawing.Point
ModifierKeys None System.Windows.Forms.Keys
MouseButtons None System.Windows.Forms.MouseButtons
+ MousePosition {System.Drawing.Point} System.Drawing.Point
Name "" String
Orientation Horizontal System.Windows.Forms.Orientation
+ Parent {Syncfusion.Windows.Forms.Chart.ChartControl} System.Windows.Forms.Control
Position Top Syncfusion.Windows.Forms.Chart.ChartLegendPosition
ProductName "Essential Chart" String
ProductVersion "3.201.1.0" String
RecreatingHandle False Boolean
Region Nothing System.Drawing.Region
RepresentationType SeriesType Syncfusion.Windows.Forms.Chart.ChartLegendRepresentationType
Right 238 Integer
RightToLeft No System.Windows.Forms.RightToLeft
Rows 1 Integer
ShowBorder True Boolean
ShowSymbol False Boolean
Site Nothing System.ComponentModel.ISite
+ Size {System.Drawing.Size} System.Drawing.Size
Spacing 4 Integer
TabIndex 3 Integer
TabStop True Boolean
Tag Nothing Object
Text "" String
Top 20 Integer
TopLevelControl Nothing System.Windows.Forms.Control
Visible True Boolean
Width 76 Integer
+ WindowTarget {System.Windows.Forms.Control.ControlNativeWindow} System.Windows.Forms.IWindowTarget

[Hamish Gunn]

The legend customitems had an item of nothing. I removed this from the code and I appear to be back working.

[Administrator]

Hi,

Thanks for the feedback.

We are currently working on optimizing the initial code that is serialized when the ChartControl is added to the form. The legend should not be created explicitly and added to the chartcontrol - it should be internal. We should have these changes done within the next few weeks.

Thanks,

Davis

[Hamish Gunn]

I have set up a DirectTrac incident.

I am not manually creating a Legend, it is the designer. It generates a line of code:

Me.chrtOutput.Legend.CustomItems = New Syncfusion.Windows.Forms.Chart.LegendItem() {Nothing}

which appears to be the problem. I comment it out and things seem to work.

Thanks

[Administrator]

Hi,

Sorry I wasn''t clear. I was just commenting that the code generation for the ChartControl should keep the legend internal.

Regards,

Davis