Bug 61077 - OpenFileDialog takes an excessive amount of time when selecting large numbers of files.
Summary: OpenFileDialog takes an excessive amount of time when selecting large numbers...
Status: NEW
Alias: None
Product: Class Libraries
Classification: Mono
Component: Windows.Forms ()
Version: 5.4 (2017-06)
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2017-12-12 14:35 UTC by fer
Modified: 2017-12-12 14:35 UTC (History)
1 user (show)

Tags:
Is this bug a regression?: ---
Last known good build:


Attachments
minimum code containing the bug (278 bytes, text/x-csharp)
2017-12-12 14:35 UTC, fer
Details


Notice (2018-05-24): bugzilla.xamarin.com is now in read-only mode.

Please join us on Visual Studio Developer Community and in the Xamarin and Mono organizations on GitHub to continue tracking issues. Bugzilla will remain available for reference in read-only mode. We will continue to work on open Bugzilla bugs, copy them to the new locations as needed for follow-up, and add the new items under Related Links.

Our sincere thanks to everyone who has contributed on this bug tracker over the years. Thanks also for your understanding as we make these adjustments and improvements for the future.


Please create a new report for Bug 61077 on GitHub or Developer Community if you have new information to add and do not yet see a matching new report.

If the latest results still closely match this report, you can use the original description:

  • Export the original title and description: GitHub Markdown or Developer Community HTML
  • Copy the title and description into the new report. Adjust them to be up-to-date if needed.
  • Add your new information.

In special cases on GitHub you might also want the comments: GitHub Markdown with public comments

Related Links:
Status:
NEW

Description fer 2017-12-12 14:35:52 UTC
Created attachment 25983 [details]
minimum code containing the bug

For an application I'm developing, I need the user to be able to open large numbers of selected files (a typical use case involves around 100 to a couple of thousand files). To do so, I use an OpenFileDialog. When selecting up to around 80 files (shift-click, control-click or control-a), the time it takes to select these files (the time it takes for them them turn blue and show in the filename textbox, measured from the moment you click on a file or press control-a) remains more or less constant. However, when selecting more than 80 files, this time increases very fast, so that it eventually takes many minutes to select a few hundred files. On Windows using the .NET framework, selecting the same amount of files is almost instant.

OS: Ubuntu 16.04
Mono version: 5.4.1.6
To compile the attached file: mcs -pkg:dotnet Program.cs
To run: mono Program.exe
Expected behaviour: OpenFileDialog should be able to select large numbers of files without any excessive delay, as is the case in Windows .NET.
Experienced behaviour: When selecting more than around 80 files, OpenFileDialog takes an excessive amount of time, from about 10 seconds to many minutes depending on how many files are selected, during which the UI is unresponsive.