How To Scan Files and Show Details of Current Scanning Without Making The Application Non-Responsive?

Question

I am developing a desktop application for pdf file management using C#.

When I search any folder for *.pdf the application stops responding for some time, which is undesired behavior.

I am using XmlWriter to write data (i.e. file name,author name,subject). Also I have a label to show current scanning of file but it only show last file after complition of scanning.

Hi all I did it by using backgroundworker. But a problem persist, when i reading current scanning through label it gave me error "Cross-thread operation not valid: Control 'label2' accessed from a thread other than the thread it was created on". Any clue why it is showing that error Thanks Regards Gourav Goyal — Gourav Goyal, Mar 19 '12 at 13:36

score 1 · Answer 1 · answered Mar 19 '12 at 11:07

This is a classic problem.

Basically the thread which displays the application is the thread which is doing all the work. So any updates/responsivness of the GUI will have to wait until its finished.

The solution to this is to make it multithreaded. The simplest way is to use a Background Worker thread which will do the writing searching and whatever, and just leave the main thread free.

http://www.dotnetperls.com/backgroundworker

score 1 · Answer 2 · answered Mar 19 '12 at 11:08

1

If you can update your program, .NET 4.0 has new IO functions that return before finishing:

For example EnumerateFiles:

http://msdn.microsoft.com/en-us/library/dd383458.aspx

answered Mar 19 '12 at 11:08

Steve Wellens

20,506
2
28
69

score 0 · Accepted Answer · edited Mar 19 '12 at 13:22

0

In addition to Haedrian's answer, I'd say that you could use the ProgressChanged event of BackGroundWorker to handle updating your progress indicators.

More specifically, you could raise that event with ReportProgress method, passing the name of the file curently scanning, and in the BackGroundWorker.ProgressChanged event handler you could update the label you want to use to show the file under scanning

edited Mar 19 '12 at 13:22

Wayne Werner

49,299
29
200
290

answered Mar 19 '12 at 11:13

themarcuz

2,573
6
36
53

Hi all I did it by using backgroundworker. But a problem persist, when i reading current scanning through label it gave me error "Cross-thread operation not valid: Control 'label2' accessed from a thread other than the thread it was created on". Any clue why it is showing that error Thanks Regards Gourav Goyal – Gourav Goyal Mar 19 '12 at 13:38
read [this post](http://stackoverflow.com/a/906097/333223) or [this post](http://stackoverflow.com/a/142069/333223) – themarcuz Mar 19 '12 at 14:03

score 0 · Answer 4 · answered Mar 19 '12 at 12:15

0

If you don't like to create an extra thread you can call

Application.DoEvents();

in the loop. This keeps application responding and updates the label.

answered Mar 19 '12 at 12:15

Florian

467
4
8

This solution keeps popping up. It's like 'Whack-A-Mole' :(( – Martin James Mar 19 '12 at 15:10

How To Scan Files and Show Details of Current Scanning Without Making The Application Non-Responsive?

4 Answers4