Background color of a dashdotted line
lazarus / 39-Graphics

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Relativity · 2015-09-02 13:08

I have a canvas, whose color I set through the statement:

Form1.Canvas.Brush.Color := RGBToColor(190,190,255); // It's light
blue

On this canvas I would like to draw, among other, lines using

  Form1.Canvas.Pen.Color := clDkGray;
  Form1.Canvas.Pen.Style := psDashDot;

that is, gray lines on blue (canvas's) background.

My problem: between the segments (and dots as well, clear) of the
psDashDot line the background color is not the canvas's but it's
white.
Can I do anything to get the canvas's blue background color also
between the psDashDot line's segments ?

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taazz · 2015-09-02 13:19

A bit of code goes a long way to showcase your problem. in general I
assume that for some reason the brush.color has changed to white by
the time you start painting the lines, try to set the brush.style to
bsClear before drawing the lines.

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Relativity · 2015-09-02 13:46

taazz, you are perfectly right. Effectively, before drawing the gray
lines I draw other things on the same canvas, that are white, setting
the brush to white.
Before the statements that draw the dashdotted lines I have set back
the brush to the canvas background color and now the dashdotted lines'
background is blue as it must be.
Thank you very much.