CODEWITHSUNDEEP
c#charts
AntonioJunior
AntonioJunior

Reputation: 959

Get chart area bounds in C#

Just to explain what I'm doing, I draw two selectors on a chart, and the part that will not be selected should appear under that blue rectangle. The part that will be selected will appear in the white area, between the two selectors. The figure below shows only the left selector.

Now, what I'm trying to do is to draw a rectangle inside a chart that always remain inside the plotting area, even when the windows is resized.

To get the top, left and bottom bounds, to draw the rectangle as shown in the figure below, I do the following:

(...)
int top = (int)(Chart.Height * 0.07);
int bottom = (int)(Chart.Height - 1.83 * top);
int left = (int)(0.083 * Chart.Width);
Brush b = new SolidBrush(Color.FromArgb(128, Color.Blue));
e.Graphics.FillRectangle(b, left, top, marker1.X - left, bottom - top);
(...)

But that's far from perfect, and it isn't drawn in the right place when the window is resized. I want the blue rectangle to always be bound on the top, left and bottom by the plotting area grid. Is that possible?

Chart

Upvotes: 2

Views: 3934

Answers (1)

zeFrenchy
zeFrenchy

Reputation: 6591

You probably want to use StripLine to achieve this. Look into the Stripline Class Documentation. Also I recommend downloading the Charting Samples which are a great help to understand the various features.

StripLine stripLine = new StripLine();    
stripLine.Interval = 0;       // Set Strip lines interval to 0 for non periodic stuff
stripLine.StripWidth = 10;    // the width of the highlighted area
stripline.IntervalOffset = 2; // the starting X coord of the highlighted area
// pick you color etc ... before adding the stripline to the axis
chart.ChartAreas["Default"].AxisX.StripLines.Add( stripLine );

This assumes you are wanting something that is not what Cursor already does (see CursorX), such as letting the user mark up areas of the plot which provides some persistence. Combining the Cursor events with the striplines above would be a good way to do that.

So to highlight the start and end of the cursor you could do this

// this would most likely be done through the designer
chartArea1.AxisX.ScaleView.Zoomable = false;
chartArea1.CursorX.IsUserEnabled = true;
chartArea1.CursorX.IsUserSelectionEnabled = true;
this.chart1.SelectionRangeChanged += new System.EventHandler<System.Windows.Forms.DataVisualization.Charting.CursorEventArgs>(this.chart1_SelectionRangeChanged);
...

private void chart1_SelectionRangeChanged(object sender, CursorEventArgs e)
    {
        chart1.ChartAreas[0].AxisX.StripLines.Clear();

        StripLine stripLine1 = new StripLine();
        stripLine1.Interval = 0;
        stripLine1.StripWidth = chart1.ChartAreas[0].CursorX.SelectionStart - chart1.ChartAreas[0].AxisX.Minimum;
        stripLine1.IntervalOffset = chart1.ChartAreas[0].AxisX.Minimum;
        // pick you color etc ... before adding the stripline to the axis
        stripLine1.BackColor = Color.Blue;
        chart1.ChartAreas[0].AxisX.StripLines.Add(stripLine1);

        StripLine stripLine2 = new StripLine();
        stripLine2.Interval = 0;
        stripLine2.StripWidth = chart1.ChartAreas[0].AxisX.Maximum - chart1.ChartAreas[0].CursorX.SelectionEnd;
        stripLine2.IntervalOffset = chart1.ChartAreas[0].CursorX.SelectionEnd;
        // pick you color etc ... before adding the stripline to the axis
        stripLine2.BackColor = Color.Blue;
        chart1.ChartAreas[0].AxisX.StripLines.Add(stripLine2);
    }

Somehow I suspect you may not have discovered the cursor yet, and doing so will make all this irrelevant. But anyway, the above code will do what you described.

Upvotes: 3

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