Scatter Line Chart in WinForms with a Custom Legend

In this post we show you how to build a multi-series scatter chart with a legend and a separator. We use MindFusion.Charting tool for WinForms.

The Data

The properties that specify data in the control are XData and YData. We add three series to each one for the three series that we want to show. Before that, we clear the arrays, to make sure no previously added data shows on the chart:

 lineChart1.XData.Add(new List{3,4,5,6,7,8,9});
 lineChart1.XData.Add(new List{1,2,3,4,5,6,7,8});
 lineChart1.XData.Add(new List{1,2,3,4,5,6,7,8,9,10});

 lineChart1.YData.Add(new List{92, 112, 241, 195, 201, 188, 212});
 lineChart1.YData.Add(new List{512, 480, 321, 491, 460, 320, 298, 241});
 lineChart1.YData.Add(new List { 340, 302, 322, 401, 487, 503, 421, 460, 513, 490 });

Chart Series

We want to show line series with scatters – since this is the default LineType, we don’t have to set anything. In order to customize our series, we add new pens to the ChartPens property. The colors of the scatters are customized with ShapePens and ShapeBrushes. We make the chart pens a bit thicker – 3 pixels.

 lineChart1.ShapeBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.FromArgb(175, 251, 175)));
 lineChart1.ShapeBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.FromArgb(176, 224, 230)));
 lineChart1.ShapeBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.FromArgb(216, 191, 216)));

 lineChart1.ChartPens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(144,238,144), 3.0f));
 lineChart1.ChartPens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(70, 130, 180), 3.0f));
 lineChart1.ChartPens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(186, 85, 211), 3.0f));

 lineChart1.ShapePens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(144, 238, 144)));
 lineChart1.ShapePens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(70, 130, 180)));
 lineChart1.ShapePens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(186, 85, 211)));

Separator Line

We would like to show a separator line that indicates the average value from all chart data. We add a SummaryValue to the SummaryValues collection. Then we customize the summary line by specifying its pen, scatter type and scatter size. We also set the pen and the brush for the scatters. Here is how we do it:

  lineChart1.SummaryPens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(255,69,0), 4.0f);
  lineChart1.SummaryShapeBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.FromArgb(255,228,225))); 
  lineChart1.SummaryShapePens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(255,69,0));

Axes Labels

We want to show custom text at the X-axis, so we set XAxisSettings.LabelType to AxisLabelType.CustomText. We use the XLabels property to add the labels. We also add a title with the XAxisSettings.TitleLabel property.

For the Y-axis we want to show the auto scale – we set it with YAxisSettings.MaxValue, YAxisSettings.MinValue and YAxisSettings.AxisDelta. We show ticks on both axes with the MajorTickLength property.

 lineChart1.YAxisSettings.AxisDelta = 50;
 lineChart1.YAxisSettings.MajorTickLength = 2F;
 lineChart1.YAxisSettings.MaxValue = 600;
 lineChart1.YAxisSettings.MinValue = 0;

 lineChart1.XAxisSettings.AxisDelta = 1;
 lineChart1.XAxisSettings.LabelType = MindFusion.Charting.AxisLabelType.CustomText;
 lineChart1.XAxisSettings.MajorTickLength = 5F;
 lineChart1.XAxisSettings.MaxValue = 11;
 lineChart1.XAxisSettings.MinValue = 0;
 lineChart1.XAxisSettings.TitleLabel = "Year";

The Legend

The labels for the legend are set with the LegendLabels property. The colors are picked automatically from the ChartPens property for each series. We place the legend at the bottom with LegendPosition and increase its offset with LegendOffset. We want the legend in one row, so we set LegendColumns to the count of the labels – 3.

 lineChart1.LegendColumns = 3;
 lineChart1.LegendLabels = new List{"Europe, Asia, North America"};
 lineChart1.LegendOffset = 30f;
 lineChart1.LegendPosition = MindFusion.Charting.Position.Bottom;

Here is a screenshot from the final chart:

Scatter Chart with a Custom Legend

Scatter Chart with a Custom Legend

You can download the sample from this link:

Download Scatter Chart with a Custom Legend Sample

The trial version of MindFusion.Chart for WinForms boasts many different samples, great charting tips and step by step tutorials. You can download it directly from here:

Download MindFusion.Charting for WinForms 3.5 Trial Version

About MindFusion.Charting for WinForms: a professional programming component for WinForms, which lets you create remarkable charts fast and easy. The tool supports all major chart types – line, pie, radar and bar – and numerous variations of them – column, area, bubble, polar, doughnut etc. 3D charts are supported as well.

Charting for WinForms supports a rich user interaction model with features like zoom, hit testing, drill down, mouse dragging and more. You can use delegates to present mathematical functions, undefined values are also acceptable. Values can be data arrays or retrieved through a database.

The appearance of each chart is fully customizable. The control offers strong design-time support with custom collection editors and chart wizards. At your disposal is a set of predefined appearance themes and a theme editor tool. A full list of the features can be read here.

Line Chart with a Separator in WinForms

In today’s post we’ll show how to build a line chart with several line series and a separator line. The separator line is drawn at a given height and divides the chart into two halves.

The Line Series

The line series are three, so we must add three lists with data to the XData and YData properties. We can do this in three ways: type the values in design time, write them in code or use data binding. In design time we use the built-in collection editors of the control:

The Series collection editor

The Series collection editor

In code we make lists with the data and add them to XData or YData:

lineChart1.YData.Add(new List { 45, 64, 38.2, 33.03, 56, 68, 39, 42 });
lineChart1.YData.Add(new List { 34, 42, 28, 42, 35, 31, 62, 55 });
lineChart1.YData.Add(new List { 22, 19, 32, 28, 17, 25, 31, 36 });

If you want to use data binding then set DataSource to the name of the data source, DataMember to specify the name of the table which will supply the data and XDataFields/YDataFields to provide the name(s) of the fields. In this case we will require three data base columns for each of the three series – separate the names with a comma e.g.

lineChart1.YDataFields = "Sales1,Sales2,Sales3";

For XData we use the same list because we want the series to appear exactly under each other:

lineChart1.XData.Add(new List { 10, 20, 30, 40, 50, 60, 70, 80 });
lineChart1.XData.Add(new List { 10, 20, 30, 40, 50, 60, 70, 80 });
lineChart1.XData.Add(new List { 10, 20, 30, 40, 50, 60, 70, 80 });

The Series

We set LineType to Line and Scatter because we want to show scatters at data points:

lineChart1.LineType = MindFusion.Charting.LineTypes.Line |  

The LineTypes enumeration allows bit wise combining of its members. We use ChartPens to set the pens for the line series. ShapesPens and ShapeBrushes set the pens for the outline and the brushes for filling the scatters:

lineChart1.ChartPens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(102, 205, 170), 6));
lineChart1.ShapePens.Add(new MindFusion.Drawing.Pen(Color.FromArgb(102, 205, 170), 2));   

The pens for the series are thicker than the pens for the scatters. The fill brush is slightly lighter:

lineChart1.ShapeBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.FromArgb(175, 251, 175)));

Finally – we set the size of the shapes and their type:


The Separator

There are two ways to draw the separator line.

The first is to add a custom summary value. In this case the separator line will be drawn from the
smallest X-data value to the biggest one, parallel to the axes.

lineChart1.AddCustomSummary(40.0, "");

The summary line is drawn with shapes at both ends, but we can hide them by setting their size to 0:

lineChart1.SummaryBrushes.Add(new MindFusion.Drawing.SolidBrush(Color.Gray));

The second way to draw the separator line is to add it as a 4th series in the XData and YData lists and add a pen for it in the ChartPens list. The advantage is that we can make the line as long as we want, in our case – as long as the length of the X-axis:

lineChart1.XData.Add(new List { 0, 90 });

The Legend

We use LegendLabels to add the labels for the line series:

lineChart1.LegendLabels = new List() { "2010", "2011", "2012" };

We set the background of the legend, but we don’t have to add any brushes or shapes for the legend items – they are taken automatically from the line series settings:

lineChart1.LegendBackgroundBrush = new MindFusion.Drawing.SolidBrush(Color.FromArgb(253, 253,  

The Grid

The GridType is GridType.HorScale. We use GridBrush, AltGridBrush and GridPen to set the colors for the grid.

lineChart1.GridPen = new MindFusion.Drawing.Pen(Color.FromArgb(200, 200, 200));
lineChart1.GridPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
lineChart1.GridType = MindFusion.Charting.GridType.HorScale;

If you make the changes to the chart in code, don’t forget to call UpdateChart() to make sure the
control knows changes have happened and the chart must be updated.

Here is the final chart:

A line chart with a separator line.

A line chart with a separator line.

The sample is available for download from here:

Download Line Chart with Separator Line Sample

You can download the trial version of the component with extensive documentation and many other samples from here:

Download MindFusion.Charting for WinForms Trial Version