Steema Central

Posted: **Fri Aug 08, 2014 2:07 pm**

For a long time, I had the following code:

  Assert(aChart.Canvas is TGDIPlusCanvas, 'Chart canvas class should be TGDIPlusCanvas but is ' + aChart.Canvas.ClassName);
  aChart.Canvas := TTeeCanvas3D.Create;
  try
  ...
  finally
    aChart.Canvas := TGDIPlusCanvas.Create;
  end;

This code gets called a lot (used to create an image of a chart for reporting). But a few days ago the Assert fired.

How can I know what class is used by default for the TChart.Canvas object?

Ed Dressel

Posted: **Fri Aug 08, 2014 3:03 pm**

Hi Ed,

The default Canvas is the one you have selected in the "Render" combobox at the "New Chart" tab at the design time options. Note this option is saved at the registry entry:

Code: Select all

HKEY_CURRENT_USER\Software\Steema Software\TeeChart Pro\Editor\DefaultCanvas

- a blank string '' is the value set for the GDI canvas.
- 'TGDIPlusCanvas' is the value set for GDI+.

Steema Central

What TChart.Canvas class is being used?

What TChart.Canvas class is being used?

Re: What TChart.Canvas class is being used?