Make Your ASP.NET Chart Look Like The Excel 2007 Chart

The Office Excel chart remains the most popular data visualization tool in the Microsoft stack.  This post describes how you can mimic the look and feel of the Excel chart using the ASP.NET chart that ships with Visual Studio 2010.

It is worth pointing out that the default ASP.NET chart already has a built-in Excel palette, but it is based on the Excel 2003 color palette:

In Office 2007, the Microsoft Excel product team changed the colors of their default chart palette and for whatever reason, the corresponding change did not make it into the ASP.NET chart.  However, you can still create the effect of an Excel 2007 chart by using a custom palette to override the built-in palettes, and adding the colors that are present on the default Excel chart.

Here is an example of the source code for this operation:

...
using System.Web.UI.DataVisualization.Charting;

public partial class PieChartPercentageLabels : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// In order to use a custom palette, you must set the default palette to None.
chart1.Palette = ChartColorPalette.None;

// This will insert Excel colors for up to 6 series on your ASP.NET chart.
chart1.PaletteCustomColors = new Color[] {
Color.FromArgb(79, 129, 189),
Color.FromArgb(192, 80, 77),
Color.FromArgb(155, 187, 89),
Color.FromArgb(128, 100, 162),
Color.FromArgb(75, 172, 198),
Color.FromArgb(247, 150, 70)};
 }
}

You can also use this technique to mimic the fonts and background colors used in the Excel chart, although I’m having a hard time trying to figure out what the default font is for the Excel 2007 chart.  Any ideas?

How to Create a Sparkline Chart in ASP.NET

In this post, I’ll show how to create a sparkline chart in ASP.NET using the Microsoft chart control.  Sparklines aren’t supported natively, but they can be implemented easily by stripping the chart down to its basic series.

Try dropping a new chart onto the Visual Studio design surface and use the code below as a starting point to generate a sparkline similar to the one shown above.

using System.Web.UI.DataVisualization.Charting
...

protected void Page_Load(object sender, EventArgs e)
 {
 // Generate random data
 Random rand = new Random();
 double high = rand.NextDouble() * 40;

 // Assign the random number to the chart to create 35 points
 for (int x = 0; x < 35; x++)
 Chart2.Series[0].Points.AddXY(DateTime.Now.AddDays(x), rand.Next(100, 200));

 // Start hiding both sets of axes, labels, gridlines and tick marks
 Chart2.ChartAreas[0].AxisX.LabelStyle.Enabled = false;
 Chart2.ChartAreas[0].AxisY.LabelStyle.Enabled = false;
 Chart2.ChartAreas[0].AxisX.MajorGrid.Enabled = false;
 Chart2.ChartAreas[0].AxisY.MajorGrid.Enabled = false;
 Chart2.ChartAreas[0].AxisX.MajorTickMark.Enabled = false;
 Chart2.ChartAreas[0].AxisY.MajorTickMark.Enabled = false;
 Chart2.ChartAreas[0].AxisX.LineWidth = 0;
 Chart2.ChartAreas[0].AxisY.LineWidth = 0;

 // Sparklines use the 'Spline' chart type to show a smoother trend with a line chart
 Chart2.Series[0].ChartType = SeriesChartType.Spline;

 // Since the line is the only thing you see on the chart, you might want to
 // increase its width.  Interestingly, you need to set the BorderWidth property
 // in order to accomplish that.
 Chart2.Series[0].BorderWidth = 2;

 // Re-adjust the size of the chart to reduce unnecessary white space
 Chart2.Width = 400;
 Chart2.Height = 100;
 }

I see why sparklines are popular but frankly, I’m not a big fan of them.  Charts should have context to understand what the trend line really means.  The “fast food” approach to data visualization will only lead to more confusion in the long run.  Finding easier ways to understand data is cool, but sometimes I feel that we’re just getting lazy as dashboard writers, compromising the difficulties of scientifically analyzing data in favor of quickly finding a pattern.  I can appreciate what Tufte was trying to get at with sparklines, but keep in mind that his use case will not work in all cases.

Anyway, rant over – enjoy your sparklines.  🙂  Feel free to post questions if this is unclear.

Happy 1000!

We recently surpassed a thousand hits in our second month of activity.  I suppose this is not a big deal for most bloggers, but hey, considering that we started off slow, we’ve picked up steam quickly!  Thanks to everyone for checking in on the site.  Feel free to contact us with any chart-related issues you may be having and we’ll do our best to answer them in this space.