Font markers are not centered on data points

[User (Legacy)]

In using font markers on my chart, the rendering of the markers is offseting 

them slightly up and to the left.

I built a sample chart using the following code that illustrates the 

problem.

When you run this, you can see that the markers are noticably shifted up and 

to the left.

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace FontMarkers

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

            chart1.ExtraStyle |= ChartFX.WinForms.ChartStyles.PaintMarker;

            chart1.AllSeries.MarkerFont = new Font("Wingdings", 10);

            chart1.AllSeries.MarkerSize = 

(short)(chart1.AllSeries.MarkerFont.Size / 2.0);

            chart1.Series[0].MarkerShape = 

(ChartFX.WinForms.MarkerShape)(-0x6c);

            chart1.Series[1].MarkerShape = 

(ChartFX.WinForms.MarkerShape)(-0x6e);

            chart1.Series[2].MarkerShape = 

(ChartFX.WinForms.MarkerShape)(-0x75);

        }

        // Draws a crosshair where the marker should be centered.

        private void chart1_PaintMarker(object sender, 

ChartFX.WinForms.PaintMarkerEventArgs e)

        {

            int c = (2 * chart1.AllSeries.MarkerSize) + 4;

            int r = c / 2;

            int x = e.Position.X;

            int y = e.Position.Y;

            e.Graphics.DrawLine(Pens.Black, x - r, y, x + r, y);

            e.Graphics.DrawLine(Pens.Black, x, y - r, x, y + r);

            int ll = x - r;

            int tt = y - r;

            e.Graphics.DrawEllipse(Pens.Black, ll, tt, c, c);

        }

    }

}

[Software FX]

The character is being draw using StringAlignment.Center for both Alignment 

and Line Alignment. For some reason Windows/GDI+ is deciding that is the 

center. You can verify this in your chart1_PaintMarker method.

You will need to either chose a symbol that is centered or paint the marker 

yourself in the chart1_PaintMarker method.

-- 

Francisco Padron

www.chartfx.com

[User (Legacy)]

Ok, I'm heading down the path of using PaintMarker to draw the marker 

myself, but I've run into a problem with the markers now being drawn twice. 

The following code will result in my marker (a black crosshair) being drawn 

as expected, but the cfx marker is also still being drawn. I set e.Handled 

to true in PaintMarker, but that had absolutely no effect. So I also set 

e.Handled = true in PrePaintMarker. But, this only caused the line to be 

suppressed (which I don't want!), and the cfx markers are still drawn.

Interestingly enough, if I change the gallery to Gallery.Scatter, the 

e.Handled = true in PrePaintMarker suppresses the cfx marker as expected.

What am I missing?

public partial class Form1 : Form

{

    public Form1()

    {

        InitializeComponent();

        chart1.Gallery = ChartFX.WinForms.Gallery.Lines;

        chart1.ExtraStyle |= ChartFX.WinForms.ChartStyles.PaintMarker;

    }

    // Draws a crosshair where the marker should be centered.

    private void chart1_PaintMarker(object sender, 

ChartFX.WinForms.PaintMarkerEventArgs e)

    {

        int c = (2 * chart1.AllSeries.MarkerSize) + 4;

        int r = c / 2;

        int x = e.Position.X;

        int y = e.Position.Y;

        e.Graphics.DrawLine(Pens.Black, x - r, y, x + r, y);

        e.Graphics.DrawLine(Pens.Black, x, y - r, x, y + r);

        int ll = x - r;

        int tt = y - r;

        e.Graphics.DrawEllipse(Pens.Black, ll, tt, c, c);

        e.Handled = true;

    }

    private void chart1_PrePaintMarker(object sender, 

ChartFX.WinForms.PaintMarkerEventArgs e)

    {

        e.Handled = true;

    }

}

[Software FX]

You won't be able to stop just the marker from drawing using e.Handled. As a 

matter of fact e.Handled = true should have prevented BOTH the marker and 

the line from being drawn.

What I suggest is that you set the MarkerSize to 0, this will eliminate the 

marker from the chart while keeping it in the legend box and other places.

-- 

Francisco Padron

www.chartfx.com