How to make foreac loop faster ?

Question

How to make foreac loop faster ?

Sani Berko 41

                    dic = new Dictionary<string, long>();  
  
                    var filesl = GetFiles(@"D:\", "*.*").ToList();  
                    foreach (var item in filesl)  
                    {  
                        FileInfo info = new FileInfo(item);  
                        if (File.Exists(info.FullName))  
                        {  
                            dic.Add(item, info.Length);  
                        }  
                    }

I'm using wpf and c#

the foreach loop takes a lot of time. i thought to use backgroundworker or something else that will make the foreach async maybe.

i want to give the user some notice on label maybe that it's getting files like "getting files progress". the problem is that when it's doing the foreach loop the whole application freeze until the foreach loop end.

Answer 1

Castorix31 69,176

the problem is that when it's doing the foreach loop the whole application freeze until the foreach loop end.

As you said, you can use a BackgroundWorker or a Thread

Sani Berko 41

How do i make the rpeortprogress inside the loop and should i invoke the label1 ?

private void Bgw_DoWork(object sender, DoWorkEventArgs e)  
        {  
            BackgroundWorker worker = sender as BackgroundWorker;  
            var filesl = GetFiles(@"D:\", "*.*").ToList();  
            foreach (var item in filesl)  
            {  
  
                FileInfo info = new FileInfo(item);  
                if (File.Exists(info.FullName))  
                {  
                    dic.Add(item, info.Length);  
                }  
            }  
        }  
  
        private void Bgw_ProgressChanged(object sender, ProgressChangedEventArgs e)  
        {  
            label1.Content = (e.ProgressPercentage.ToString() + "%");    
        }

I tried to make the reporting like this :

private void Bgw_DoWork(object sender, DoWorkEventArgs e)  
        {  
            var filesl = GetFiles(@"D:\", "*.*");  
            foreach (var item in filesl)  
            {  
  
                bgw.ReportProgress(0,item);  
  
                FileInfo info = new FileInfo(item);  
                if (File.Exists(info.FullName))  
                {  
                    dic.Add(item, info.Length);  
                }  
            }  
        }

but this make the whole application to be freezing when making the while loop.

Answer 2

I would simply show progress by file name in a label using code as per below (written in .NET Core). The only thing I did not include was code to cancel which can be done with a CancellationToken

public class FileOperations  
{  
    public delegate void OnTraverse(string sender);  
    public event OnTraverse Traverse;  
    public delegate void OnDone();  
    public event OnDone Done;  
  
    public async Task CollectFiles(string path, string searchPattern, SearchOption searchOption = SearchOption.TopDirectoryOnly)  
    {  
        using var enumerator = await Task.Run(() => Directory.EnumerateFiles(path, searchPattern, searchOption).GetEnumerator());  
        while (await Task.Run(() => enumerator.MoveNext()))  
        {  
            Traverse?.Invoke(enumerator.Current);  
        }  
  
        Done?.Invoke();  
    }  
}

Form code

using System;  
using System.IO;  
using System.Windows.Forms;  
using IterateFoldersApp.Classes;  
  
namespace IterateFoldersApp  
{  
    public partial class Form1 : Form  
    {  
        public Form1()  
        {  
            InitializeComponent();  
        }  
  
        private async void button1_Click(object sender, EventArgs e)  
        {  
            FileOperations operations = new();  
            operations.Traverse += OperationsOnTraverse;  
            operations.Done += OnDone;  
            await operations.CollectFiles("TODO", "*.*", SearchOption.AllDirectories);  
        }  
  
        private void OnDone()  
        {  
            MessageBox.Show("Done");  
        }  
  
        private void OperationsOnTraverse(string sender)  
        {  
            FileInfo info = new (sender);  
            if (File.Exists(sender))  
            {  
                label1.Text = $"Working {info.Name}";  
            }  
        }  
    }  
}

Edit: If you want to figure out total files

private static int FileCount(string directory)  
{  
    DirectoryInfo dirInfo = new(directory);  
    return dirInfo.EnumerateDirectories()  
        .AsParallel()  
        .SelectMany(di => di.EnumerateFiles("*.*", SearchOption.AllDirectories))  
        .Count();  
}

Then look at IProgress<int> and Report off IProgress.

How to make foreac loop faster ?

2 answers

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