http://www.telerik.com/help/wpf/common-export-support.html

Resolution: 
Add an option to export the chart to an image or a stream using the ExportToImage methods.

Add vertical cursors for Line series that stay in place unless the user drags them. Each cursor should select the data points that covers. The cursor should allow setting its position programmatically.

Currently values can only increase from left to right and from bottom to top.

IMPROVE. RadChartView - one should be able to access the tooltip instance in order to customize it (change font, delay, etc)

To reproduce:
- Add at least two series and zoom the chart so the point from one of the series are visible only
- Move the TrackBall
- The Track ball is not shown for some of the points. 

Steps to reproduce:
1. Add a chart to a form.
2. Add any cartesian series
3. Set the LabelFitMode of the horizontal axis to Rotate.

You will see that labels have incorrect layout.

Currently RadChartView does not support null values.

http://www.telerik.com/help/winforms/chart-features-marked-zones.html

Add print functionality

One should be able to add annotations at certain positions within RadChartView.

I'm using version 2012.3.1310.40
I use ChartView to create a pie chart with the following data
Assets          2248550.22
Income             19748.67
Equity           2228253.95
Liability                 547.60

So, when the chart displays, the Percentage is set as follows:
Assets       50%
Income        0%
Equity         50%
Liability        0%

I notice when the percentage is 0% for any data, the pie chart shows "0%" near the chart title (please see attachment).  Or if the calculated data returns 0, it doesn't show any percentage on the chart, but it will shows "NaN" near the title as well. (please see attachment).

To reproduce:
public Form1()
{
    InitializeComponent();

    ScatterSeries series = new ScatterSeries();
    series.DataPoints.Add(new ScatterDataPoint(5, 5));
    series.DataPoints.Add(new ScatterDataPoint(4, 2));
    series.DataPoints.Add(new ScatterDataPoint(-1, 3));
    series.DataPoints.Add(new ScatterDataPoint(8, 4));

    radChartView1.Series.Add(series);

    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.Minimum = -10;
    horizontalAxis.Maximum = 10;
}
private void radButton1_Click(object sender, EventArgs e)
{
    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.DesiredTickCount = 20;
}

Workaround:

public class CustomLassoZoomController : LassoZoomController
{
    protected override ActionResult OnMouseUp(MouseEventArgs e)
    {
        if (this.MouseDownLocation == Point.Empty || this.MouseMoveLocation == Point.Empty)
        {
            return Controller.Empty;
        }

        return base.OnMouseUp(e);
    }
}

public Form1()
{
    InitializeComponent();

    BarSeries barSeries = new BarSeries("Performance", "RepresentativeName");
    barSeries.Name = "Q1";
    barSeries.DataPoints.Add(new CategoricalDataPoint(177, "Harley"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(128, "White"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(143, "Smith"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(111, "Jones"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(118, "Marshall")); 
    this.radChartView1.Series.Add(barSeries);

    BarSeries barSeries2 = new BarSeries("Performance", "RepresentativeName");
    barSeries2.Name = "Q2";
    barSeries2.DataPoints.Add(new CategoricalDataPoint(153, "Harley"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(141, "White"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(130, "Smith"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(88, "Jones"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(109, "Marshall"));
    this.radChartView1.Series.Add(barSeries2);

    CustomLassoZoomController lassoZoomController = new CustomLassoZoomController();
    radChartView1.Controllers.Add(lassoZoomController);
}

Note: similar to the axis, the series should also have ClipLabels property which will control whether the labels will be clipped or not.

How to reproduce: zoom and pan along the chart
public Form1()
{
    InitializeComponent();

    this.radChartView1.CreateRenderer += radChartView1_CreateRenderer;
    this.radChartView1.ShowPanZoom = true;

    BarSeries barSeries = new BarSeries();
    Random rand = new Random();
    for (int i = 1; i < 10; i++)
    {
        barSeries.DataPoints.Add(new CategoricalDataPoint(rand.Next(100), i));
    }

    barSeries.ShowLabels = true;
    this.radChartView1.Series.Add(barSeries);
}

Workaround:
 public partial class Form1 : Form
 {
     public Form1()
     {
         InitializeComponent();

         this.radChartView1.CreateRenderer += radChartView1_CreateRenderer;
         this.radChartView1.ShowPanZoom = true;

         BarSeries barSeries = new BarSeries();
         Random rand = new Random();
         for (int i = 1; i < 10; i++)
         {
             barSeries.DataPoints.Add(new CategoricalDataPoint(rand.Next(100), i));
         }

         barSeries.ShowLabels = true;
         this.radChartView1.Series.Add(barSeries);
     }

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

         for (int i = 0; i < this.DrawParts.Count; i++)
         {
             BarLabelElementDrawPart labelPart = this.DrawParts[i] as BarLabelElementDrawPart;
             if (labelPart != null)
             {
                 this.DrawParts[i] = new CustomLabelElementDrawPart((BarSeries)labelPart.Element, this);
             }
         }
     }
 }

 public class CustomLabelElementDrawPart : BarLabelElementDrawPart
 {
     public CustomLabelElementDrawPart(ChartSeries owner, IChartRenderer renderer)
         : base(owner, renderer)
     { }
     
     public override void Draw()
     {
         Graphics graphics = this.Renderer.Surface as Graphics;
         CartesianSeries cartesianSeries = this.Element as CartesianSeries;
         if (cartesianSeries != null)
         {
             CartesianArea area = (CartesianArea)cartesianSeries.GetType().GetField("area", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(cartesianSeries);
             RectangleF clipRect = (RectangleF)area.GetType().GetMethod("GetCartesianClipRect", BindingFlags.Instance | BindingFlags.NonPublic).Invoke(area, new object[] { });//.GetCartesianClipRect();
             graphics.SetClip(clipRect);
         }

         base.Draw();

         graphics.ResetClip();
     }
 }

This problem is related to different serie types are added to the chartview

When trying to drill down PieChart on RadChartView the code throws exception.

Workaround: private void radChartView_Drill(object sender, DrillEventArgs e){    e.View.Parent = this.radChartViewUsers.ChartElement.Wrapper;    e.View.AreaType = ChartAreaType.Pie;    //do drill logic}

How to reproduce:
Dim table As New DataTable()
table.Columns.Add("Name", GetType(String))
table.Columns.Add("X", GetType(Integer))
 
For i As Integer = 0 To 99
    table.Rows.Add($"User {i}", i)
Next
 
Dim series As New BarSeries()
series.DataSource = table
series.CategoryMember = "Name"
series.ValueMember = "X"
 
RadChartView1.Series.Add(series)
 
CType(RadChartView1.Area, CartesianArea).Orientation = Orientation.Horizontal
         
Dim panZoomController As New ChartPanZoomController()
panZoomController.PanZoomMode = ChartPanZoomMode.Vertical
RadChartView1.Controllers.Add(panZoomController)
 
RadChartView1.Zoom(1, 8)

Workaround: create a custom ChartPanZoomController
Dim panZoomController As New MyChartPanZoomController()
panZoomController.PanZoomMode = ChartPanZoomMode.Vertical
RadChartView1.Controllers.Add(panZoomController)

Public Class MyChartPanZoomController
    Inherits ChartPanZoomController

    Protected Overrides Function OnMouseMove(e As MouseEventArgs) As ActionResult

        Dim cartesianArea As CartesianArea = TryCast(Me.Area, CartesianArea)
        If cartesianArea Is Nothing Then
            Return MyBase.OnMouseMove(e)
        End If

        Dim panPoint As Point? = Me.GetType().BaseType.GetField("panPoint", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)

        If e.Button = MouseButtons.Left AndAlso panPoint.HasValue Then
            Dim offsetX As Double = Me.GetType().BaseType.GetField("offsetX", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)

            Dim currentOffsetX As Double = offsetX
            Dim defaultAxis As Axis = If(cartesianArea.Orientation = Orientation.Horizontal,
                                         Me.Area.GetType().GetMethod("GetDefaultFirstAxis", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me.Area, New Object() {}),
                                         Me.Area.GetType().GetMethod("GetDefaultSecondAxis", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me.Area, New Object() {}))

            If Me.PanZoomMode = ChartPanZoomMode.Horizontal OrElse Me.PanZoomMode = ChartPanZoomMode.Both Then
                currentOffsetX += (panPoint.Value.X - e.Location.X) * -1

                If currentOffsetX > 0 Then
                    currentOffsetX = 0
                End If

                If currentOffsetX < defaultAxis.Model.LayoutSlot.Width * (DirectCast(cartesianArea.View, IChartView).ZoomWidth - 1) Then
                    currentOffsetX = -defaultAxis.Model.LayoutSlot.Width * (DirectCast(cartesianArea.View, IChartView).ZoomWidth - 1)
                End If
            End If

            Dim offsetY As Double = Me.GetType().BaseType.GetField("offsetY", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)
            Dim currentOffsetY As Double = offsetY
            If Me.PanZoomMode = ChartPanZoomMode.Vertical OrElse Me.PanZoomMode = ChartPanZoomMode.Both Then
                currentOffsetY += (panPoint.Value.Y - e.Location.Y) * -1

                If currentOffsetY > 0 Then
                    currentOffsetY = 0
                End If

                If currentOffsetY < -defaultAxis.Model.LayoutSlot.Height * (DirectCast(cartesianArea.View, IChartView).ZoomHeight - 1) Then
                    currentOffsetY = -defaultAxis.Model.LayoutSlot.Height * (DirectCast(cartesianArea.View, IChartView).ZoomHeight - 1)
                End If
            End If

            cartesianArea.View.Pan(currentOffsetX, currentOffsetY)
        End If

        Return Controller.Empty

    End Function

End Class

To reproduce:

private void RadChartView1_LabelFormatting(object sender, ChartViewLabelFormattingEventArgs e)
{
    var dataPoint = e.LabelElement.DataPoint as CategoricalDataPoint;
    if (dataPoint != null)
    {
         e.LabelElement.IsVisible = false;
    }
}

Workaround:
private void RadChartView1_LabelFormatting(object sender, ChartViewLabelFormattingEventArgs e)
{
    var dataPoint = e.LabelElement.DataPoint as CategoricalDataPoint;
    if (dataPoint != null)
    {
        e.LabelElement.Text = "";
    
    }
}

How to reproduce: explicitly set the border color of the series

Workaround:
public partial class Form1 : Form
{
    private RangeSelectorViewElement chartElement;

    public Form1()
    {
        InitializeComponent();

        LineSeries lineSeries = new LineSeries();
        lineSeries.Name = "Line";
        lineSeries.BorderColor = Color.Green;
        lineSeries.DataPoints.Add(new CategoricalDataPoint(20, "Jan"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(22, "Apr"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(12, "Jul"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(19, "Oct"));
        this.radChartView1.Series.Add(lineSeries);

        this.chartElement = this.radRangeSelector1.RangeSelectorElement.AssociatedElement as RangeSelectorViewElement;
        this.chartElement.SeriesInitialized += ChartElement_SeriesInitialized;
    }

    private void ChartElement_SeriesInitialized(object sender, SeriesInitializedEventArgs e)
    {
        if (e.Series.Name == "Line")
        {
            e.Series.BorderColor = this.radChartView1.Series.Where(s => s.Name == "Line").First().BorderColor;
        }
    }
}

Steps to reproduce:
1. Add chart to a form.
2. Add two bar series with CombineMode set to Stack100
3. Add two data points to the series with values 0.0 and identical category
4. Run the project an you will see an exception.