c# - Is it possible to set a chart datasource from a generic list?

Question

I have a list created from a linq query that contains 2 columns of data.

var result = root.Descendants().Elements("sensor")
                 .Where(el => (string)el.Attribute("name") == "Sensor1") 
                 .Elements("evt") 
                 .Select(el => new { t1 = el.Attribute("time").Value, 
                                     v1 = el.Attribute("val").Value }) 
                 .ToList()

I'm trying to use the chart control datasource to use that list, but when I call the bind method I receive this error:

System.ArgumentException was unhandled HResult=-2147024809
Message=Series data points do not support values of type <>f__AnonymousType0`2[System.Double,System.Decimal] only values of these types can be used: Double, Decimal, Single, int, long, uint, ulong, String, DateTime, short, ushort.

//result is a generic list defined as var result = root.Descendants()
chart1.DataSource = result;
chart1.DataBind(); // This is line that causes the exception.

Regards.

Answer 1

Yes it is possible, but not by binding the list to the Chart itself.

There are several quite different methods to do Chart Databinding, all with different sets of pros and cons..

I suggest using the Series.Points.DataBindXY or Series.Points.DataBind methods.

Here is an example:

// create a list with test data:
List<PointF> points = new List<PointF>();
for (int i = 0; i < 100; i++) points.Add(new PointF(i, 1f * i / 2f * R.Next(8)));

Now create a generic list from it:

var al = points.Select(x => new { t1 = x.X, v1 = x.Y }).ToList();

Now this works:

someSeries.Points.DataBindXY(al, "t1", al, "v1");

or also this:

someSeries.DataBind(al, "t1", "v1", "" );

In your case you would write maybe this:

chart1.Series[0].Points.DataBind(result, "t1", "v1");

Note that a Chart typically can only display pairs of values whereas a DGV can create as many columns as the DataSource has. So Chart needs a little help in finding the x- and y-values..