Canvas.Arc function does not work
lazarus / 39-Graphics

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newman · 2016-10-26 07:31

Hi,

I am trying to get the Canvas.Arc function to draw an arc on a form,
however it does not work.

I pasted the following code in the Form.OnPaint event.

Canvas.Pen.Color:= clRed;
Canvas.Pen.Width:= 1;
Canvas.Arc(106,6,139,64,139,6,139,6);

However nothing gets drawn.

I am using Lazarus 1.6 on OS X (EL Capitan).

Other functions like ArcTo, LineTo, Ellipse etc works,

Please help

thanks
nm

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User137 · 2016-10-26 07:53

To me that draws a small red circle on top.

Win10, some ages old Lazarus 1.3.

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marcov · 2016-10-26 08:23

Try to pain in the onpaint event.

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newman · 2016-10-26 10:23

I created a fresh project and pasted the paint code in the OnPaint
event of the form.

Quoteprocedure TForm1.FormPaint(Sender: TObject);
begin
  Canvas.Pen.Color:= clRed;
Canvas.Pen.Width:= 1;
Canvas.Arc(106,6,139,64,139,6,139,6);

end;
However even now nothing is drawn on the form...

thanks
nm

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newman · 2016-10-26 10:56

OK, now I changed some of the parameters in the arc function, I am
able to draw some arcs on the screen

thanks
nm