Solved

Double buffering Custom control

Posted on 2004-03-28
8
665 Views
Last Modified: 2007-12-19
i created a custome control that draws alot of boxes with text in them uisng GDI, I also implemented a custome scrolling, so when the user tryies to scroll i actually move the panel that contains drawing up and down.

i get alot of flicker while scrolling, i tried using double buffer techniqes but it seems to be to slow or i'm doing some thing worng,
here is the code that uses GDI to draw:


private void DrawProgram (ProgramDetail _program, int channelY)
            {
                  Bitmap offScreenBmp = new Bitmap(_program.ProgramSize.Width, _program.ProgramSize.Width);
                  Graphics GrapoffScreenDC = Graphics.FromImage(offScreenBmp);


                  Rectangle rc =  new Rectangle(new Point(XMargin , YMargin),new Size(_program.ProgramSize.Width - (XMargin * 2) ,_program.ProgramSize.Height-(YMargin * 2))) ;
                  DrawRoundedRectangle(_program.BackColor,rc,MyGraphics);
                  
                        MyGraphics.DrawString(_program.Cat,NoteFont,ProgramBrush,SideMargin + PicDim + SidePicMargin +  _program.LocationX,TopMargin + BetweenMargin + ProgramFont.Size +channelY);

                        
                        //Draw Title Text
                        MyGraphics.DrawString(_program.Title,ProgramFont,ProgramBrush,SideMargin + PicDim + SidePicMargin+_program.LocationX,TopMargin+channelY);
      
                  MyGraphics.DrawImageUnscaled(offScreenBmp,_program.LocationX,channelY);
                  MyGraphics.Dispose  ();
                  offScreenBmp.Dispose();
                  GrapoffScreenDC.Dispose  ();


            }
0
Comment
Question by:saturn_one
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
8 Comments
 
LVL 2

Expert Comment

by:codewiz51
ID: 10700870
This isn't going to help, and it's not intended as an answer.  I primarily program in MFC/C++.  What you want to do is use a BitBlt to scroll your display rapidly.  When I searched MSDN, I only came up with unmanaged C++ examples and some VB stuff.  So, given that, I think you will need to make some windows api calls to do your scrolling.

I am relatively new to c#, and while I love the language, I have not had a good experience with graphical programming.  I get a lot of the same screen flickering and I have associated it with the performance of .Net.  I have used the techniques from this article on CodeProject to do BitBlt'ing in .Net: http://codeproject.com/vb/net/BitBlt.asp. and http://www.codeguru.com/Csharp/Csharp/cs_graphics/drawing/article.php/c6137/.

Wish I could have been more help, but realtime graphics (ie scrolling) has not been a good thing on .Net.  Everytime I end up using API calls.  The second article shows some better techniques in .Net, but for high speed scrolling, it as less that adequate.
0
 
LVL 48

Expert Comment

by:AlexFM
ID: 10701526
0
 

Author Comment

by:saturn_one
ID: 10701643
i did try putting
SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);

in my form constructor, but it doesn't seem to help.i stil get alot of flickers
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 20

Expert Comment

by:TheAvenger
ID: 10701931
Why do you put it in your FORM constructor? Put it in your CONTROL constructor. When you put it in the form, it works for the form, not for the control, and you have a problem in the control.
0
 

Author Comment

by:saturn_one
ID: 10706313
I tried that too, doesn't help!
0
 

Author Comment

by:saturn_one
ID: 10706548
this, might help u guys find what the problems, i figured out that the onpaint method gets called 4-6 times every time i try to scroll! do u think that this could be causing the flicker?
0
 

Accepted Solution

by:
AnnieMod earned 0 total points
ID: 10749327
Question PAQ'd and 500 points refunded

AnnieMod
EE Admin
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article series is supposed to shed some light on the use of IDisposable and objects that inherit from it. In essence, a more apt title for this article would be: using (IDisposable) {}. I’m just not sure how many people would ge…
This article describes a simple method to resize a control at runtime.  It includes ready-to-use source code and a complete sample demonstration application.  We'll also talk about C# Extension Methods. Introduction In one of my applications…

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question