To reproduce:
this.radChartView1.AreaType = Telerik.WinControls.UI.ChartAreaType.Polar;
RadarLineSeries series = new RadarLineSeries(new SizeF(8f, 8f));
series.DataPoints.Add(new CategoricalDataPoint(0.0, "Coding"));
series.LegendTitle = String.Format("Coding");
series.BorderWidth = 2;
radChartView1.Series.Add(series);
series.PolarAxis.Minimum = 0d;
series.PolarAxis.Maximum = 0.0;
series.PolarAxis.TickLength = 4;

Workaround: 
public Form1()
        {
            InitializeComponent();
         
           StringFormat.GenericTypographic.Alignment = StringAlignment.Near;
        }

Workaround: create a custom BarSeriesDrawPart  and override the Draw method

public class CustomBarSeriesDrawPart : BarSeriesDrawPart
{
    public CustomBarSeriesDrawPart(BarSeries series, IChartRenderer renderer)
        : base(series, renderer)
    { }

    public override void Draw()
    {
        bool shouldDraw = IsElementValid();
        if (shouldDraw)
        {
            Graphics graphics = this.Renderer.Surface as Graphics;
            GraphicsState state = graphics.Save();
            Region clipRegion = graphics.Clip;

            CartesianSeries cartesianSeries = this.Element as CartesianSeries;
           

            if (cartesianSeries != null)
            {
                FieldInfo fi = cartesianSeries.GetType().GetField("area", BindingFlags.NonPublic | BindingFlags.Instance);
                CartesianArea  area = fi.GetValue(cartesianSeries) as CartesianArea;
                MethodInfo mi = area.GetType().GetMethod("GetCartesianClipRect", BindingFlags.NonPublic | BindingFlags.Instance);
                mi.Invoke(area, null);

                RectangleF clipRect = (RectangleF)mi.Invoke(area, null); 
                graphics.Clip = new Region(clipRect);
            }

            DrawSeriesParts();

            graphics.Clip = clipRegion;
            graphics.Restore(state);
        }
    }
}

RadChartView Control: corrupts legend when set Series IsVisibleInLegend = False in Properties at design time

Simply added a few extra series , and then tried to turn them off in the legend 

screen shot shows too many legent items for the series in the properties window

How to reproduce: 
public Form1()
        {
            InitializeComponent();

            DataTable source = new DataTable();
            source.Columns.Add("PreviousGoal", typeof(decimal));
            source.Columns.Add("CurrentCategory", typeof(System.DateTime));

            source.LoadDataRow(new object[] { null, "6/1/15" }, true);
            source.LoadDataRow(new object[] { null, "6/2/15" }, true);
            source.LoadDataRow(new object[] { null, "6/3/15" }, true);
            source.LoadDataRow(new object[] { null, "6/4/15" }, true);
            source.LoadDataRow(new object[] { null, "6/5/15" }, true);

            this.radChartView1.DataSource = source;

            SteplineSeries previousGoalSeries = new SteplineSeries();
            previousGoalSeries.DataSource = source;
            previousGoalSeries.ValueMember = "PreviousGoal";
            this.radChartView1.Series.Add(previousGoalSeries);

            SteplineSeries previousGoalSeries1 = new SteplineSeries();
            previousGoalSeries1.DataSource = source;
            previousGoalSeries1.ValueMember = "CurrentCategory";
            this.radChartView1.Series.Add(previousGoalSeries1);

            this.radChartView1.ShowTrackBall = true;

        }

Workaround: add the series with null values last
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        DataTable source = new DataTable();
        source.Columns.Add("PreviousGoal", typeof(decimal));
        source.Columns.Add("CurrentCategory", typeof(System.DateTime));

        source.LoadDataRow(new object[] { null, "6/1/15" }, true);
        source.LoadDataRow(new object[] { null, "6/2/15" }, true);
        source.LoadDataRow(new object[] { null, "6/3/15" }, true);
        source.LoadDataRow(new object[] { null, "6/4/15" }, true);
        source.LoadDataRow(new object[] { null, "6/5/15" }, true);

        this.radChartView1.DataSource = source;
        SteplineSeries previousGoalSeries1 = new SteplineSeries();
        previousGoalSeries1.DataSource = source;
        previousGoalSeries1.ValueMember = "CurrentCategory";
        this.radChartView1.Series.Add(previousGoalSeries1);

        SteplineSeries previousGoalSeries = new SteplineSeries();
        previousGoalSeries.DataSource = source;
        previousGoalSeries.ValueMember = "PreviousGoal";
        this.radChartView1.Series.Add(previousGoalSeries);

        this.radChartView1.ShowTrackBall = true;
    }
}

Having issues withVS2013 & 2015 Q1 Winforms RadChartView control

1. WYSIWYG in design time does not refresh properly after changing axis collection parameters, unless close and reopen the parent winform or custom control
2. by changing an axis collection parameter , seem to end up with multiple extra axes series (originally had axisX, AxisY, and after a minor param change ended up with axis 0 thru 5 (6 in total) and all series where now using axis4 & axis5 not my original axis?
3. I can't see to toggle display on/off of series in winforms via the legend, yet in wpf web it is possible? will this feature be added later?

attached is example of WYSIWYG not working

improvement Suggestions:
I would love to have a major and minor grid (similar to ref: http://thumbs.dreamstime.com/z/screen-digital-oscilloscope-two-types-signal-33269502.jpg)  as most of my work is measurement and scientific in nature. 

I would like to ensure the ratio of X-Y is fixed so that on resize of the control the grid does not skew or stretch  and I loose 1:1 aspect ratio

I look forward to your feedback ;)

How to reproduce: 
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        this.radChartView1.AreaType = ChartAreaType.Pie;
        PieSeries series = new PieSeries();
        series.DataPoints.Add(new PieDataPoint(0, "Germany"));
        series.DataPoints.Add(new PieDataPoint(0, "United States"));
        series.DataPoints.Add(new PieDataPoint(0, "France"));
        series.DataPoints.Add(new PieDataPoint(0, "United Kingdom"));
        series.ShowLabels = true;
        this.radChartView1.Series.Add(series);
        this.radChartView1.ShowSmartLabels = true;
    }
}

Workaround: 
this.radChartView1.ShowSmartLabels = false;

By making IsVisibleInLegend = false at design time, get exception during compile (see attached) and also exceptions at run time

Aim:
I need to be able to hide certain chart text from legend

 

To reproduce:
- Add line series with large point size and null points.
- Hover a near a point which is close to null point (the line break).

Workaround:
public class MyChartTooltipController : ChartTooltipController
{
    protected override ActionResult OnMouseMove(MouseEventArgs e)
    {
        for (int i = 0; i < this.Area.Series.Count; i++)
        {
            DataPoint point = this.Area.Series[i].HitTest(e.X, e.Y);
            DataPoint hoveredPoint = typeof(ChartTooltipController).GetField("hoveredPoint", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance).GetValue(this) as DataPoint;
            ToolTip toolTip = typeof(ChartTooltipController).GetField("toolTip", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance).GetValue(this) as ToolTip;
            if (point != null && hoveredPoint != point)
            {
                hoveredPoint = point;
                var result = typeof(CategoricalDataPoint).GetMethod("GetTooltipValue", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance).Invoke(hoveredPoint, null);
                
                if (result == null)
                {
                    return new ChartRefreshResult();
                }
            }
        }
        return base.OnMouseMove(e);
    }
}



 

To reproduce:

Create a RadChartView with LineSeries. Subscribe to the CreatePointElement event and use the following code:

void Chart_CreatePointElement(object sender, ChartViewCreatePointElementEventArgs e)
{
    e.DataPointElement = new DataPointElement(e.DataPoint);
    e.DataPointElement.GradientStyle = GradientStyles.Solid;
    e.DataPointElement.GradientAngle = 270;
    e.DataPointElement.Shape = new DiamondShape();
    e.DataPointElement.BackColor = Color.Red;
    e.DataPointElement.BackColor2 = Color.Blue;
    e.DataPointElement.BackColor3 = Color.Blue;
    e.DataPointElement.BackColor4 = Color.Blue;
}

The elements paint when you use ChamferedRectShape.

Workaround 
class MyDiamondShape : ElementShape
{
    public override GraphicsPath CreatePath(Rectangle bounds)
    {
        GraphicsPath path = new GraphicsPath();
        
        path.AddPolygon(new PointF[]
        {
            new PointF(bounds.X + 0.5f * bounds.Width, bounds.Top),
            new PointF(bounds.Right, bounds.Y + 0.5f * bounds.Height),
            new PointF(bounds.X + 0.5f * bounds.Width, bounds.Bottom),
            new PointF(bounds.Left, bounds.Y + 0.5f * bounds.Height)
        });
    
        return path;
    }
}

class MyStarShape : ElementShape
{
    private int arms;
    private float innerRadiusRatio;
    
    public MyStarShape()
    {
        this.arms = 8;
        this.innerRadiusRatio = 0.2f;
    }
    
    /// <summary>
    /// Creates Star like shape. Overrides CreatePath method in the base class
    /// ElementShape.
    /// </summary>
    public override GraphicsPath CreatePath(Rectangle bounds)
    {
        GraphicsPath path = new GraphicsPath();
        
        double angle = Math.PI / arms;
        double offset = Math.PI / 2d;
        PointF center = new PointF(bounds.X + bounds.Width / 2f, bounds.Y + bounds.Height / 2f);
        PointF[] points = new PointF[arms * 2];
        
        for (int i = 0; i < 2 * arms; i++)
        {
            float r = (i & 1) == 0 ? bounds.Width / 2f : bounds.Width / 2f * innerRadiusRatio;
            
            float currX = center.X + (float)Math.Cos(i * angle - offset) * r;
            float currY = center.Y + (float)Math.Sin(i * angle - offset) * r;
        
            points[i] = new PointF(currX, currY);
        }
        
        path.AddPolygon(points);
        return path;
    }
}

class MyHeartShape : ElementShape
{
    public override GraphicsPath CreatePath(Rectangle bounds)
    {
        GraphicsPath path = new GraphicsPath();
        
        path.AddArc(new Rectangle(bounds.X, bounds.Y, bounds.Width / 2, bounds.Height / 2), 150, 210);
        path.AddArc(new Rectangle(bounds.X + bounds.Width / 2, bounds.Y, bounds.Width / 2, bounds.Height / 2), 180, 210);
        path.AddLine(path.GetLastPoint(), new Point(bounds.X + bounds.Width / 2, bounds.Bottom));
        path.CloseFigure();
    
        return path;
    }
    
}

To reproduce:
- Enable the Trackball.
- Add 2 series to the chart.
- Remove and add back the first one.
- Move the mouse over the chart.

Workaround:
class MyChartTrackballController : ChartTrackballController
{
    protected override string GetPointText(DataPoint point)
    {
        if (point.Presenter != null)
        {
            return base.GetPointText(point);
        }
        else
        {
            CategoricalDataPoint p = point as CategoricalDataPoint;
            if (p!= null)
            {
                return p.Value.ToString();
            }
        }
        return "";
    }
} 

To reproduce:

public Form1()
{
    InitializeComponent();

    this.radChartView1.ShowPanZoom = true;
    Random rand = new Random();
    this.radChartView1.AreaType = ChartAreaType.Polar;
    for (int i = 0; i < 85; i++)
    {
        RadarLineSeries radarPointSeries = new RadarLineSeries();
        for (int j = 0; j < 8; j++)
        {
            radarPointSeries.DataPoints.Add(new CategoricalDataPoint(rand.Next(1, 100), "X" + j));
        }
        this.radChartView1.Series.Add(radarPointSeries);
    }
}

Workaround: set the ShowPanZoom property after the chart is populated with data.

when overlay a radlabel on a radchartview, chartview constantly refreshes
label backcolor set to transparent

tried to recreate this with a sample cs project but wouldn't reproduce!

video has two instances of the same user control on the form
notice that right hand instance does not update when radlabel is added

attached is video of it working fine, then add label ontop , then see it misbehaving  with fast refresh flicker!  not only that it also prevents other items in the user controls from updating and the other user control on the form from updating

have attached sample c# project (but cant reproduce)

To reproduce
- Add step-line series with two data points.

Workaround:
public class CustomCartesianRenderer : CartesianRenderer
{
    public CustomCartesianRenderer(CartesianArea area) : base(area)
    {
    }

    protected override void Initialize()
    {
        base.Initialize();

        for (int i = 0; i < this.DrawParts.Count; i++)
        {
            SteplineDrawPart linePart = this.DrawParts[i] as SteplineDrawPart;
            if (linePart != null)
            {
                this.DrawParts[i] = new CustomDrawPart((SteplineSeries)linePart.Element, this);
            }
        }
    }
}

public class CustomDrawPart : SteplineDrawPart
{
    public CustomDrawPart(LineSeriesBase series, IChartRenderer renderer)
        : base(series, renderer)
    {
    }
    protected override System.Drawing.Drawing2D.GraphicsPath GetLinePaths(PointF[] points)
    {
        //return base.GetLinePaths(points);
        GraphicsPath path = new GraphicsPath();

         if (points.Length > 1)
        {
            if (this.Element is LineSeries && ((LineSeries)this.Element).Spline)
            {
                path.AddCurve(points, ((LineSeries)this.Element).SplineTension);
            }
            else
            {
                bool isVertical = this.Element.View.GetArea<CartesianArea>().Orientation == System.Windows.Forms.Orientation.Vertical;

                for (int i = 1; i < points.Length; i++)
                {
                    PointF x = points[i - 1];
                    PointF y = points[i];

                    if (isVertical)
                    {
                        path.AddLine(x.X, x.Y, y.X, x.Y);
                        path.AddLine(y.X, x.Y, y.X, y.Y);
                    }
                    else
                    {
                        path.AddLine(x.X, x.Y, x.X, y.Y);
                        path.AddLine(x.X, y.Y, y.X, y.Y);
                    }
                }
            }
        }
        else
        {
            return null;
        }

        return path;
    }
}
//change like this
void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
{
    e.Renderer = new CustomCartesianRenderer((CartesianArea)e.Area);
}
 

public Form1()
{
    InitializeComponent();

    AreaSeries areaSeries = new AreaSeries();
    areaSeries.DataPoints.Add(new CategoricalDataPoint(13, "Jan"));
    areaSeries.DataPoints.Add(new CategoricalDataPoint(20, "Apr"));
    areaSeries.DataPoints.Add(new CategoricalDataPoint(15, "Jul"));
    areaSeries.DataPoints.Add(new CategoricalDataPoint(16, "Oct"));
    this.radChartView1.Series.Add(areaSeries);

    AreaSeries areaSeries2 = new AreaSeries(); 
    areaSeries2.DataPoints.Add(new CategoricalDataPoint(15, "Jan"));
    areaSeries2.DataPoints.Add(new CategoricalDataPoint(25, "Apr"));
    areaSeries2.DataPoints.Add(new CategoricalDataPoint(27, "Jul"));
    areaSeries2.DataPoints.Add(new CategoricalDataPoint(18, "Oct"));
    this.radChartView1.Series.Add(areaSeries2);

    this.radChartView1.ShowTrackBall = true;
    this.radChartView1.Series.First().IsVisible = false;
}

Please refer to the attached sample video.

Workaround 1: remove the series instead of hiding it.

Workaround 2:

private void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
{
     e.Renderer = new CustomCartesianRenderer(e.Area as CartesianArea);
}

public class CustomCartesianRenderer : CartesianRenderer
{
    public CustomCartesianRenderer(CartesianArea area) : base(area)
    {
    }

    private int renderPass = 0;

    public override void Draw(object context)
    {
        if (renderPass < 2)
        {
            if (this.Area.View.Owner.Control.Site == null)
            {
                for (int i = 0; i < this.Area.Series.Count; i++)
                {
                    if (this.Area.Series[i].IsVisible && !this.Area.Series[i].Model.IsArrangeValid)
                    {
                        this.Area.View.Layout();
                        renderPass++;
                        return;
                    }
                }
            }
        }
        FieldInfo fi = typeof(ChartRenderer).GetField("surface", BindingFlags.Instance | BindingFlags.NonPublic);
        if (context != null)
        {
            fi.SetValue(this, context);
        }
        Initialize();

        for (int i = 0; i < this.DrawParts.Count; i++)
        {
            this.DrawParts[i].Draw();
        }
    }
}

To reproduce:
Enable the smart labels and export the chart using custom size:
 this.radChartView1.ExportToImage(@"C:\df.png", new Size(1100,1100), System.Drawing.Imaging.ImageFormat.Png);

Workaround:
class MyPieRenderer : PieRenderer
{
    
    public MyPieRenderer(PieArea area) : base(area)
    {
    }

    protected override void Initialize()
    {
        base.Initialize();

        var area = this.View;

        SmartLabelsController smartController = null;
        for (int i = 0; i < area.View.Controllers.Count; i++)
        {
            smartController = area.View.Controllers[i] as SmartLabelsController;

            if (smartController != null)
            {
                RadRect viewport = area.View.Viewport;
                viewport.X -= area.View.Margin.Left;
                viewport.Y -= area.View.Margin.Top;
                viewport.Width += area.View.Margin.Horizontal;
                viewport.Height += area.View.Margin.Vertical;

                Rectangle plotArea = new Rectangle((int)viewport.X, (int)viewport.Y, (int)viewport.Width, (int)viewport.Height);
                smartController.CalculateLabelsPositions(area.View.Series, plotArea);

                break;
            }
        }
    }
}
// change like this 
void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
{
    e.Renderer = new MyPieRenderer((PieArea)e.Area);
}

To reproduce:
 protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            radChartView1 = new RadChartView();
            radChartView1.Parent = this;

            this.radChartView1.AreaType = ChartAreaType.Pie;
            PieSeries series = new PieSeries();
            series.DataPoints.Add(new PieDataPoint(50, "Germany"));
            series.DataPoints.Add(new PieDataPoint(70, "United States"));
            series.DataPoints.Add(new PieDataPoint(40, "France"));
            series.DataPoints.Add(new PieDataPoint(25, "United Kingdom"));
            series.ShowLabels = true;
            this.radChartView1.Series.Add(series);

            (series.Children[0] as PiePointElement).RadiusAspectRatio = 1.2f;
      }

Workaround:

  protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            radChartView1 = new RadChartView();
            radChartView1.Parent = this;

            this.radChartView1.AreaType = ChartAreaType.Pie;
            PieSeries series = new PieSeries();
            series.DataPoints.Add(new PieDataPoint(50, "Germany"));
            series.DataPoints.Add(new PieDataPoint(70, "United States"));
            series.DataPoints.Add(new PieDataPoint(40, "France"));
            series.DataPoints.Add(new PieDataPoint(25, "United Kingdom"));
            series.ShowLabels = true;
            this.radChartView1.Series.Add(series);

            (series.Children[0] as PiePointElement).RadiusAspectRatio = 1.2f;

            this.radChartView1.CreateRenderer += new ChartViewCreateRendererEventHandler(radChartView1_CreateRenderer);
        }

        void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
        {
            e.Renderer = new CustomPieRenderer(e.Area as PieArea);
        }

        public class CustomPieRenderer : PieRenderer
        {
            public CustomPieRenderer(PieArea area)
                : base(area)
            { }

            protected override void Initialize()
            {
                base.Initialize();

                for (int i = 0; i < this.DrawParts.Count; i++)
                {
                    PieSeriesDrawPart piePart = this.DrawParts[i] as PieSeriesDrawPart;
                    if (piePart != null)
                    {
                        this.DrawParts[i] = new CustomPieSeriesDrawPart((PieSeries)piePart.Element, this);
                    }
                }
            }

        }

        class CustomPieSeriesDrawPart : PieSeriesDrawPart
        {
            public CustomPieSeriesDrawPart(PieSeries series, IChartRenderer renderer)
                : base(series, renderer)
            {

            }

            public override void DrawSeriesParts()
            {
                //base.DrawSeriesParts();

                PieSeriesModel model = this.Element.Model as PieSeriesModel;
                float diameter = CalculateDiameter();

                if (diameter > 0)
                {
                    DrawPieSegments(model, diameter);
                }
            }

            private float CalculateDiameter()
            {
                PieSeriesModel model = this.Element.Model as PieSeriesModel;
                double diameter = Math.Min((float)model.LayoutSlot.Width, (float)model.LayoutSlot.Height) * ((PieSeries)Element).RadiusFactor;

                return (float)diameter;
            }

            private void DrawPieSegments(PieSeriesModel model, float diameter)
            {
                Graphics gr = ((PieRenderer)this.Renderer).Graphics;
                RadGdiGraphics radGraphics = new RadGdiGraphics(gr);

                for (int i = 0; i < model.DataPoints.Count; i++)
                {
                    PiePointElement childElement = (PiePointElement)this.Element.Children[i];
                    PieDataPoint piePoint = (PieDataPoint)childElement.DataPoint;

                    float finalDiameter = diameter * childElement.RadiusAspectRatio;
                    GraphicsPath path = ConstructGraphicsPath(piePoint, model.LayoutSlot, finalDiameter);
                    UpdatePointPaths(piePoint, path);
                    System.Drawing.RectangleF rect = GetPieSectionRect(piePoint, model.LayoutSlot, finalDiameter);

                    childElement.GradientAngle = (float)(piePoint.StartAngle + piePoint.SweepAngle / 2);
                    FillPrimitiveImpl fill = new FillPrimitiveImpl(childElement, null);
                    fill.PaintFill(radGraphics, path, rect);

                    BorderPrimitiveImpl border = new BorderPrimitiveImpl(childElement, null);
                    border.PaintBorder(radGraphics, null, path, rect);
                }
            }

            protected System.Drawing.RectangleF GetPieSectionRect(PieDataPoint point, RadRect modelLayoutSlot, float diameter)
            {
                System.Drawing.RectangleF result;

                float x = (float)(modelLayoutSlot.X + (modelLayoutSlot.Width - diameter) / 2);
                float y = (float)(modelLayoutSlot.Y + (modelLayoutSlot.Height - diameter) / 2);

                result = new System.Drawing.RectangleF(x, y, Math.Max(diameter, 1f), Math.Max(diameter, 1f));

                if (point.OffsetFromCenter > 0)
                {
                    System.Drawing.PointF offset = GetOffset(point.StartAngle + (point.SweepAngle / 2), (diameter / 2) * (point.OffsetFromCenter));
                    result.X += offset.X;
                    result.Y += offset.Y;
                }

                return result;
            }

            private System.Drawing.PointF GetOffset(double angle, double radius)
            {
                double angleInRad = angle * RadMath.DegToRadFactor;

                double x = (Math.Cos(angleInRad) * radius);
                double y = (Math.Sin(angleInRad) * radius);

                return new System.Drawing.PointF((float)x, (float)y);
            }
        }