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Chris Miles
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 Posted: Sat Jul 12, 2003 4:51 pm Post subject: Painting to Canvas on every iteration of a while loop not wo |
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My question is: im using c++ builder and using the inbuild BPL stuff for windows applications, I have a while loop which i want to repaint the Canvas object on each iteration.. but when running the loop it freezes until the last iteration and then it repaints... any ideas on how can i get arround this? thanks
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Damon Chandler (TeamB)
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| Posted: Sat Jul 12, 2003 8:23 pm Post subject: Re: Painting to Canvas on every iteration of a while loop no |
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Hi Chris,
| Quote: | I have a while loop which i want to repaint the Canvas object on each
iteration.. but when running the loop it freezes until the last
iteration and then it repaints...
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How are you repainting the Canvas within your loop?
--
Damon (TeamB)
BCBCAQ - http://bcbcaq.bytamin-c.com
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Damon Chandler (TeamB)
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| Posted: Sun Jul 13, 2003 5:43 pm Post subject: Re: Painting to Canvas on every iteration of a while loop no |
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Chris,
| Quote: | this->paint(m_outputGraphCanvas);
void SOM::paint(TCanvas *Canvas) {...}
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What does the following show?
ShowMessage(m_outputGraphCanvas->ClassName());
I ask because the solution depends on whether you're drawing to a display
device context (DC) or to a memory DC. If your m_outputGraphCanvas member
is assigned a pointer to a TControlCanvas object (e.g., m_outputGraphCanvas
= Form1->Canvas), then you're drawing to a display DC. If
m_outputGraphCanvas points to a TBitmapCanvas object (e.g.,
m_outputGraphCanvas = Image1->Canvas), then you're drawing to a memory DC.
If you're drawing to a display DC, then the rendering should be visible as
it's executed. If you're drawing to a memory DC, then the results won't be
visible until the bitmap associated with the memory DC is rendered to the
screen. In the latter case, assuming you're using a TImage component,
simply call the TImage::Refresh() method within your loop.
Good luck,
--
Damon (TeamB)
BCBCAQ - http://bcbcaq.bytamin-c.com
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Dumboo
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| Posted: Thu Jul 31, 2003 5:07 am Post subject: Re: Painting to Canvas on every iteration of a while loop no |
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| Quote: | I have a while loop which i want to repaint the Canvas object on each
iteration.. |
It will never work,
I have experienced it,
you have to give time to the canvas to Repaint itself, since u r in a same
Thread you cannot either you have to simulate the while(..) loop using Timer
or run your code through seperate thread
-Dumboo :-)
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