how to draw sth on a Panel permanently?

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Sowen Zhang - 20 Feb 2007 22:27 GMT

Hi all

I need to draw sth to a Panel in an action, for instance

Graphics g = palCanvas.getGraphics();
g.setColor(Color.cyan);
g.fillPolygon(p);

Yes, the polygon is drawn, but after I update any control in the same form
or resize the window, the polygon disappears.

Can someone tell me how can I keep it?
Thanks!

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Hong.
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Andrew Thompson - 20 Feb 2007 22:35 GMT

...

> I need to draw sth to a Panel in an action, for instance
>
> Graphics g = palCanvas.getGraphics();

This is the wrong way to approach
custom painting. It hould be done
on the Graphics object supplied to
paint()/paintComponent().

See,
<http://java.sun.com/docs/books/tutorial/uiswing/painting/index.html>
for further details.

Andrew T.

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Sowen Zhang - 20 Feb 2007 22:39 GMT

good reference, thanks a lot!

Signature

Best Regards!
Hong.

> ...
>> I need to draw sth to a Panel in an action, for instance
[quoted text clipped - 11 lines]
>
> Andrew T.

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how to draw sth on a Panel permanently?

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