Hi, there is any way to easily put an arrow on the end of a line? Im trying to draw custom axes inside my graphic using lines. There is any way to put an arrow on the end?

m_Line2 = (NLineSeries)m_Chart.Series.Add(SeriesType.Line);
m_Line2.Name = "Alimentador";
m_Line2.InflateMargins = true;
m_Line2.DataLabelStyle.Visible = true;

m_Line2.MarkerStyle.Visible = false;
m_Line2.SamplingMode = SeriesSamplingMode.Enabled;
m_Line2.LineSize = new NLength(50);
m_Line2.MarkerStyle.PointShape = PointShape.Cylinder;
m_Line2.MarkerStyle.Width = new NLength(1.5f, NRelativeUnit.ParentPercentage);
m_Line2.MarkerStyle.Height = new NLength(1.5f, NRelativeUnit.ParentPercentage);
m_Line2.UseXValues = true;
m_Line2.Values.Add(0);
m_Line2.XValues.Add(-125);
m_Line2.Values.Add(0);
m_Line2.XValues.Add(20);
m_Line2.BorderStyle.Color = Color.Black;

I thought this m_Line2.MarkerStyle.PointShape = PointShape.Cylinder should do something like this


Thanks

Hi Andre,

This can be achieved with custom painting - the following example shows how to add a line cap at the end of the line:

  public class CustomPaintCallback : NPaintCallback
  {
   public CustomPaintCallback(NChartControl chartControl, NChart chart, NLineSeries line)
   {
    m_Line = line;
    m_Chart = chart;
    m_ChartControl = chartControl;
   }

   public override void OnAfterPaint(NPanel panel, NPanelPaintEventArgs eventArgs)
   {
    NScale2DToViewTransformation scale2View = new NScale2DToViewTransformation(m_ChartControl.View.Context, m_Chart, (int)StandardAxis.PrimaryX, (int)StandardAxis.PrimaryY);

    int count = m_Line.Values.Count;
    if (count < 2)
    {
     return;
    }

    double y1 = (double)m_Line.Values[count - 2];
    double x1 = (double)m_Line.XValues[count - 2];

    double y2 = (double)m_Line.Values[count - 1];
    double x2 = (double)m_Line.XValues[count - 1];

    NPointF point1 = new NPointF();
    NPointF point2 = new NPointF();
    scale2View.Transform(new NVector2DD(x1, y1), ref point1);
    scale2View.Transform(new NVector2DD(x2, y2), ref point2);

    // now paint the arrow
    Graphics graphics = eventArgs.Graphics.DeviceGraphics;
    GraphicsState state = graphics.Save();

    double angle = Math.Atan2(point1.Y - point2.Y, point1.X - point2.X);
    graphics.TranslateTransform(point2.X, point2.Y);

    double rad2Degree = 57.2958f;
    graphics.RotateTransform((float)(rad2Degree * angle) - 90);

    using (SolidBrush brush = new SolidBrush(Color.Black))
    {
     using (GraphicsPath path = new GraphicsPath())
     {
      float arrowSize = 5;
      path.AddLine(new PointF(0, 0), new PointF(-arrowSize, arrowSize));
      path.AddLine(new PointF(-arrowSize, arrowSize), new PointF(arrowSize, arrowSize));
      path.CloseAllFigures();
      graphics.FillPath(brush, path);
     }
    }
    

    graphics.Restore(state);
   }

   NLineSeries m_Line;
   NChart m_Chart;
   NChartControl m_ChartControl;
  }

  private void Form1_Load(object sender, EventArgs e)
  {
   NChart m_Chart = nChartControl1.Charts[0];

   NLineSeries m_Line2 = (NLineSeries)m_Chart.Series.Add(SeriesType.Line);
   m_Line2.Name = "Alimentador";
   m_Line2.InflateMargins = true;
   m_Line2.DataLabelStyle.Visible = true;

   m_Line2.MarkerStyle.Visible = false;
   m_Line2.SamplingMode = SeriesSamplingMode.Enabled;
   m_Line2.LineSize = new NLength(50);
   m_Line2.MarkerStyle.PointShape = PointShape.Cylinder;
   m_Line2.MarkerStyle.Width = new NLength(1.5f, NRelativeUnit.ParentPercentage);
   m_Line2.MarkerStyle.Height = new NLength(1.5f, NRelativeUnit.ParentPercentage);
   m_Line2.UseXValues = true;
   m_Line2.Values.Add(0);
   m_Line2.XValues.Add(-125);
   m_Line2.Values.Add(10);
   m_Line2.XValues.Add(20);
   m_Line2.BorderStyle.Color = Color.Black;

   m_Chart.PaintCallback = new CustomPaintCallback(nChartControl1, m_Chart, m_Line2);
  }

Hope this helps - let us know if you meet any problems...

Best Regards,
Nevron Support Team

Fantastic!! Worked perfectly.

I have one more last question to finish my customized 2D graphic.

On my attachment I made an red line using Paint and I wanted to do this on my graphic. Can you tell me where on Nevron Samples I can find a example to draw an Arc? Like giving 2 points and a angle to draw it.

The theta labels im sure I can find how to do it, I have just this arc drawing question.

Thank you, the nevron support is amazing!

Hi Andre,

You can in fact draw anything that's supported by GDI+ - there is no dedicated example for drawing ars, however the GraphicsPath has a method called AddArc which you can use for this purpose. Following is the link in MSDN:

http://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.graphicspath.addarc.aspx

Hope this helps - let us know if you meet any problems.

Best Regards,
Nevron Support Team

Hi,

GraphicPath.AddArc function is define as "add arc to current figure". I used, but nothing happend. But I was expecting it, because I didnt make any association with my NChartControl. How can I make this association?

Thanks,

Andre

Hi Andre,

How did you call this function? In general the GDI+ api it is out of the scope of the forum...

Best Regards,
Nevron Support Team