Using Zedgraph to make dynamically updated statistics

Zedgraph is a very good. NET in the open source project of the statistical map, in a previous essay mentioned that, compared with some of the other statistical control, zedgraph because it is directly on the canvas, rather than generate a picture display, so the performance is better, in such as the real time trend chart of the stock market, display CPU usage and so on real-time strong application has Good performance, the method is not difficult, but because very few people write this article, but also happened in other forums to see the problem, so write the following example.

When zedgraph a line chart, all the coordinate points are kept in pointpairlist, which is the x,y coordinate when drawing lines. To make a dynamic line chart, you actually add point coordinates to the pointpairlist, and then refresh it.

The code is simple:

Random ran = new Random ();

Pointpairlist list = new Pointpairlist ();

LineItem Mycurve;

Random is used to generate the sample data, which is the y-coordinate, pointpairlist is used to store the point collection. Mycarve is the line to draw. Of course, you can't forget to add a zedgraph control to your form.

To highlight the effect, we add the following code to the form's Load event:

This.zedGraphControl1.GraphPane.Title.Text = "Dynamic Line chart";

This.zedGraphControl1.GraphPane.XAxis.Title.Text = "Time";

This.zedGraphControl1.GraphPane.YAxis.Title.Text = "Quantity";

This.zedGraphControl1.GraphPane.XAxis.Type = ZedGraph.AxisType.DateAsOrdinal;

for (int i = 0; I <= i++)

{

Double x = (double) New Xdate (DateTime.Now.AddSeconds (100-i));

Double y = ran. Nextdouble ();

List. ADD (x, y);

}

DateTime dt = DateTime.Now;

Mycurve = ZedGraphControl1.GraphPane.AddCurve ("My Curve",

List, Color.darkgreen, symboltype.none);

This.zedGraphControl1.AxisChange ();

This.zedGraphControl1.Refresh ();