Tuesday, May 29, 2012

MSChart Extension - Zoom and Pan Controls

NEW: MSChart Extension 2.0 Released - Find out more

Introduction - About MSChart Extension

MSChart Extension is an extension package created to provide additional features and functions to Microsoft Chart (MSChart) control. This control is released under MIT license.

Download MSChart Extension (Source and Assembly) - Version 1.2.0
Download MSChart Extension Demo - Version 1.2.0

Get latest source code and package from NuGet or GitHub.
GitHub: https://github.com/Code-Artist/MSChartExtension
NuGet: http://nuget.org/packages/MSChartExtension


Microsoft Chart (MSChart) in Visual Studio is a great Windows Forms (WinForms) controls to create chart for standalone application. However, there are several features that could be added and improved to make this controls more user friendly.

Zooming and panning are two common feature for chart when dealing with large amount of data. Unfortunately, there are no easy way to have these two features enabled with MSChart. Although there is a built in Zoom controls, it is not very user friendly which described below. On the other hand, panning is not available. Search around web but didn't find any reliable solutions.

I tried to implement these two features in MSChart by writing custom codes and YES it is possible. Instead of copy and paste the same piece of code over and over again to every single project that I need, I created this MSChart Extension class which put all these additional features in a separated assembly which can be simply add as reference when needed.

Features List

  • Fast Clear Data
  • Windowed Zoom in and Zoom Out
  • Pan
  • Show / hide series  
  • Annotations (Version 1.2.0)

Fast Clear Data
MSChart has a known problem which impact most of the users which is the speed of clearing data points. This become worst when dealing with large amount of data. Workaround for this solution had been published by Microsoft and users to fix this problem. See previous post: Speedup MSChart for more details.

    //Clear Data Points

Windowed Zoom
This is a improvement version of zoom control with zoom out (full view) instead of using built in zoom control in MSChart. The main reason for recreate this feature is because zooming out is really a pain where need to zoom out each axis separately by clicking a button on the axis by number of time that I zoomed in. Moreover, the built in controls does not seems to works well with annotations.

Notes: Zoom out function is available in pop up menu when chart is zoomed.

Panning allowed user to move zoomed window using mouse. This is much better than moving the horizontal and vertical scroll bar.

Show / Hide Series
Sometimes, it is necessary to plot chart with multiple series for data comparison. However, it would not be easy to visualize the data for each individual series when we have multiple series overlapping each other. Show and hide series function provide a flexibility to hide each series as you wish. MSChart extension will automatically detect number of series used in chart, no setup is required to use this feature. Each series can be hide / show from context menu.

Annotations (Version 1.2.0)
Extensions methods to create chart annotations are added in Version 1.2.0 as below.
  • DrawHorizontalLine
  • DrawVerticalLine
  • DrawLine
  • DrawRectangle
  • DrawText
The standard way to add an annotation to MSChart in run-time is create an annotation object and add it to the annotation list of the chart. Adding one annotation normally involve several lines of codes as we need to overwrite some of those default properties in order to show the annotation correctly in the chart.

With the extension methods provided above, adding annotation can be easily done in single function call. Colors, line weight, line style and position are exposed as input parameters.
Functions listed above are just few of the commonly used annotation type. You may create similar function for other types of annotation using the similar methods.

NOTE: Please note that these functions are created to add annotation to first chart area with primary axis.

Codes below shows an example of adding horizontal line to chart. ClipToChartArea, AxisXName, YAxisName, and IsInfinite are properties that we need to overwrite its default values. AxisXName and YAxisName are hidden properties which is not visible in IntelliSense.

Custom annotation name should only be assigned after annotation was added to annotation list. This is because the Name property will be overwrite with auto generated value when adding the object to annotation list.

        public static void DrawHorizontalLine(this Chart sender, double y, 
            Drawing.Color lineColor, string name = "",
            int lineWidth = 1, ChartDashStyle lineStyle = ChartDashStyle.Solid)
            HorizontalLineAnnotation horzLine = new HorizontalLineAnnotation();
            string chartAreaName = sender.ChartAreas[0].Name;
            horzLine.ClipToChartArea = chartAreaName;
            horzLine.AxisXName = chartAreaName + "\\rX";
            horzLine.YAxisName = chartAreaName + "\\rY";
            horzLine.IsInfinitive = true;
            horzLine.IsSizeAlwaysRelative = false;
            horzLine.Y = y;
            horzLine.LineColor = lineColor;
            horzLine.LineWidth = lineWidth;
            horzLine.LineDashStyle = lineStyle;
            if (!string.IsNullOrEmpty(name)) horzLine.Name = name;


Using MSChart Extension

To use this extension package, simply add MSChart assembly to reference of the project.
Additional features and dedicated context menu can be enabled by the following function call.
    private void AttachChartControl()
        //Enable Extension Functions and Context Menu
        myChart.EnableZoomAndPanControls(ChartCursorSelected, ChartCursorMoved);
    private void ChartCursorSelected(double x, double y)
        txtChartSelect.Text = x.ToString("F4") + ", " + y.ToString("F4");
    private void ChartCursorMoved(double x, double y)
        txtChartValue.Text = x.ToString("F4") + ", " + y.ToString("F4");

ChartCursorSelected and ChartCursorMoved are two optional callback to notify parent when chart coordinate changed. ChartCursorSelected will be called when a point in chart area is selected whereas ChartCursorMoved will trigger when mouse is move in chart area. x and y values in these two call backs are values for X-Axis and Y-Axis. It is hard coded to use primary axis at this moment.

This operation is reversible by calling the following function.

    //Disable Extension Functions and restore chart settings

MSChart Extension come with a built in pop up menu which allow user to use features such as zoom and pan controls during run-time. All functions such as zoom, pan, select and series hide / show can be access from context menu. This context menu is shown when right click mouse in chart with Zoom and Pan controls enabled as show above.



Merged Context Menu (Version 1.1.1)
MSChart Extension's context menu will automatically merge with user assigned context menu when Zoom and Pan controls is enabled. Disabling the control will restore the context menu to original state.

Cloning context menu is implemented using Menu_Cloner by jmertus.

Speedup Zoom Out (ZoomReset) (Version 1.1.2)
Time need to zoom out chart is proportional to number of times chart is zoomed.
A work around is implemented to speed up this process to stop chart repaint until zoom out process is complete. SuspendDrawing is called before ZoomReset to stop painting whereas ResumeDrawing is called after ZoomReset to resume chart painting.

    using System.Runtime.InteropServices;
    static class WindowMessagesNativeMethods
        private static extern long SendMessage(IntPtr hWnd, Int32 wMsg, 
                           [MarshalAs(UnmanagedType.Bool)] bool wParam, 
                           Int32 lParam);
        private const int WM_SETREDRAW = 11;
        public static void SuspendDrawing(Control parent) 
            SendMessage(parent.Handle, WM_SETREDRAW, false, 0); 
        public static void ResumeDrawing(Control parent) 
            SendMessage(parent.Handle, WM_SETREDRAW, true, 0); 

Future Improvement

  • Add option to select between primary / secondary axis for Select tool and callback functions.
  • Append MSChart Extension's context menu to user defined context menu if exists.
  • Implement 2 cursor to calculate different between 2 points. 

Version History

02/04/2012    Original document.
03/04/2012    Reformat.
04/04/2012    Added description to call back functions and future improvement list.
24/04/2012    Published as NuGet Package
29/05/2012    Added Version 1.1.1 and Version 1.1.2 updates.
18/07/2012   Version 1.2.0: Added annotations functions.
03/07/2013   Version 1.3.0: Improved zoom function, refactoring...
30/08/2014   Version 1.4.0: Support secondary axis zoom and pan functions.
08/10/2015   Version 1.4.1: Added license file.


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