Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Displaying file in a CScrollView

Posted on 1997-03-06
1
Medium Priority
?
337 Views
Last Modified: 2013-11-19
I am using Visual C++ v1.5, under WFW.
I would like to display a filename in a CScrollView, the
file may be >64k, I am currently doing this using TextOut for
each line in the file inside the OnDraw method of the ScrollView.
However, this is very slow, how can I optimise it - has
anyone any sample code?? I have tried using the RectVisible
function inside CDC, and it produces strange results. Any
code/optimisation ideas would be greatly welcome.
Thanks,
Douglas
0
Comment
Question by:dd021197
[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
1 Comment
 
LVL 1

Accepted Solution

by:
rhgaracci earned 50 total points
ID: 1300448
You are probably redrawing all of your text every time you scroll, so you need to restrict your text drawing to only the region invalidated by CScrollview.  The SCRIBBLE tutorial (STEP 8) CScrollView::OnDraw() has a good example.  Your implementation will be different the priciple will be the same.  You need to examine the clipping box returned by GetClipBox() to determine which text lines to draw.  Since you know the height of each line by your y increment for TEXTOUT, you should be able to divide the y coordinate of the clip region by the increment to get the starting line.  You can do a similar manipulation to get the number of lines by dividing the box height by the increment.  By restricting the drawing, you will speed up your app.
0

Featured Post

Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

Question has a verified solution.

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

Introduction: Hints for the grid button.  Nested classes, templated collections.  Squash that darned bug! Continuing from the sixth article about sudoku.   Open the project in visual studio. First we will finish with the SUD_SETVALUE messa…
Introduction: Dialogs (2) modeless dialog and a worker thread.  Handling data shared between threads.  Recursive functions. Continuing from the tenth article about sudoku.   Last article we worked with a modal dialog to help maintain informat…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
Want to learn how to record your desktop screen without having to use an outside camera. Click on this video and learn how to use the cool google extension called "Screencastify"! Step 1: Open a new google tab Step 2: Go to the left hand upper corn…

593 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