Simple code but does not running

[burhankhan]

Hi:
I want to draw a rectangle in a dialog when i click on a button.

I write this code in the onbutton click function:

CPaintDC dc(this);
CRect r(20,20,100,100);
dc.Rectangle(&r);


This code does not showing any thing or any error.

What is mistake.
Burhan

[Aram Hambardzumyan]

in CPaintDC's overview msdn says:

A CPaintDC object can only be used when responding to a WM_PAINT message, usually in your OnPaint message-handler member function'.

try using CCLientDC in your case

[greka]

it's bad practice to start acquaintance with graphics using buttons.

For implementing owner-drawing buttons you have to create custom class (as well as override some methods, capture mouse, etc). It's easier to use CBitmapButton.
Sample here: http://www.codeproject.com/buttonctrl/hoverbutton.asp
or here:
http://www.codeproject.com/buttonctrl/

Better explained sample here:
http://www.codeproject.com/buttonctr...overbutton.asp

hope this will by handy for you.

[Agregat]

Или проще: GetDC()

[burhankhan]

Originally Posted by greka

it's bad practice to start acquaintance with graphics using buttons.

For implementing owner-drawing buttons you have to create custom class (as well as override some methods, capture mouse, etc). It's easier to use CBitmapButton.
Sample here: http://www.codeproject.com/buttonctrl/hoverbutton.asp
or here:
http://www.codeproject.com/buttonctrl/

Better explained sample here:
http://www.codeproject.com/buttonctr...overbutton.asp

hope this will by handy for you.

Sorry u cannot understand what i want to say.
I don't need any hoverbutton or owner draw button control.
It is not metter what type of button i am using.

Problem was that when i click on button a rectangle should draw on the client area of dialog. And my code is not running. Code is above.

I hope u will understand.
Thanks for ur oppinon.

Burhan