This is a behaviour change between 16.8.8.12 and 17.3.6.12

On your helpful recommendation we added an INPaintCallBack and use OnBeforePaint to allow the user to change the symbol sizes on chart lines by turning the mouse wheel. This works fine in 16.8.8.12 and 17.3.6.12. However, we have found that the OnBeforePaint code affects chart export in 17.3.612 - the chart is not resized in the export when the export size is changed form the default size.

I have tracked this to these lines of code:

this.chartControl.document.Calculate();
this.chartControl.RecalcLayout();

If they are removed the export is the correct size but the symbol resizing has not been applied to the export.

Is there a different way to achieve this in 17.3.6.12?

I also notice that previously I could reorganise panel layout; e.g. moving the legend panel from right to left and the chart would redraw. Now I have to explicitly call NChartControl.Refresh().

Some general advice on the changes and recommended strategies would be much appreciated.

Thanks

Kevin

Hi Kevin,

We were not able to replicate the problem - we tested with the following code:

using Nevron.Chart;
using Nevron.Chart.WinForm;
using Nevron.GraphicsCore;
using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
 public partial class Form1 : Form
 {
  public Form1()
  {
   InitializeComponent();
  }

  class MyPaintCallback : INPaintCallback
  {
   public MyPaintCallback(NChartControl chartControl)
   {
    m_ChartControl = chartControl;
   }
   public void OnAfterPaint(NPanel panel, NPanelPaintEventArgs eventArgs)
   {
    throw new NotImplementedException();
   }

   public void OnBeforePaint(NPanel panel, NPanelPaintEventArgs eventArgs)
   {
    bool requiresRecalculate = true;

    foreach (NSeries series in m_ChartControl.Charts[0].Series)
    {
     NPointSeries pointSeries = series as NPointSeries;
     if (pointSeries != null)
     {
      pointSeries.Size = new NLength(4, NGraphicsUnit.Pixel);
     }
    }

    if (requiresRecalculate)
    {
     m_ChartControl.document.Calculate();
     m_ChartControl.RecalcLayout();
    }
   }

   NChartControl m_ChartControl;
  }

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

   NPointSeries point = new NPointSeries();
   chart.Series.Add(point);
   Random rand = new Random();

   for (int i = 0; i < 20; i++)
   {
    point.Values.Add(rand.Next(100));
   }

   chart.PaintCallback = new MyPaintCallback(nChartControl1);

   nChartControl1.ImageExporter.SaveToFile("c:\\temp\\check.bmp", new NBitmapImageFormat());
  }
 }
}

And both the chart on the form and the exported image looked correct.

Best Regards,
Nevron Support Team

"the chart is not resized in the export when the export size is changed from the default size."

You are using the default size.

Hi Kevin,
The control works properly - when you call nChartControl.RecalcLayout it will use the default view context which has different size than the one in the view context that currently serves for image export - that's why you get the same size in the

Best Regards,
Nevron Support Team