Solved

Delphi ListView and LARGE query

Posted on 2003-11-12
5
602 Views
Last Modified: 2008-03-10
Greetings

I have a listview on my form that gets populated by records from either a flat file or SQL server database.

With the flat file for example, if the amount of records starts to exceed 10 000
the reporting becomes way to slow and GUI locks up while in the loop of retrieving the records.

Should I look at having a seperate thread doing the work ?

Iterating through the records consumes only a couple of seconds, but uncommenting the code that places the data in the listview and then running the query takes up time ?

Any suggestions ?
 
Regards
 Engwi
0
Comment
Question by:Engwi
[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
5 Comments
 
LVL 14

Expert Comment

by:sudhakar_koundinya
ID: 9737528
Ok

some suggestions

1. If you are getting total information with in few seconds, i suggest to take that info in dynamic collection classes (i.e dynamic vectors or hash tables or linked lists)  say 1000 per class for example

2. Create the thread that adds the information in the list
3. create the instance to new thread, send the ppointer of collection object  to the thread instance and start the thread.
4. like that call all threads at a time.
5. But take care that only 10 to 20 threads (depending on system peformance) should be in running mode. i.e at any moment of time ,  application execution should only support 10 to 20 threads
6. take care of syncronization to the listbox object also (if necessary)

hope you got my ideas.


Regards,
Koundinya
0
 
LVL 2

Accepted Solution

by:
Robn earned 20 total points
ID: 9739337
are you using beginupdate and endupdate on the listview items?
If not, this will speed up the population of the list.

Regards,
Rob
0
 

Author Comment

by:Engwi
ID: 9739370
Rob

Will try that first and let you know.

Thanks
 Engwi
0
 
LVL 17

Expert Comment

by:Wim ten Brink
ID: 9756047
Have you considered turning the listview into a virtual listview?
0
 

Expert Comment

by:lamtl354
ID: 9761011
what is virtual listview??
0

Featured Post

Independent Software Vendors: 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!

Question has a verified solution.

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

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…
Finding and deleting duplicate (picture) files can be a time consuming task. My wife and I, our three kids and their families all share one dilemma: Managing our pictures. Between desktops, laptops, phones, tablets, and cameras; over the last decade…

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