Random File Repeat Win Form in c#

Question

Random rand = new Random();
string[] filess = Directory.GetFiles("Select Directory");
string randomFile = filess[rand.Next(filess.Length)];

Answer 1

Hello,

Sample project for below is in this repository

Using the following class to store files

public class FileItem  
{  
    public string FolderName { get; set; }  
    public string FileName { get; set; }  
    public bool Selected { get; set; }  
    public override string ToString() => FileName;  
}  

Randomize the files

public static class Extensions  
{  
    private static readonly Random random = new Random();  
  
    public static void Shuffle<T>(this IList<T> list)  
    {  
        int count = list.Count;  
          
        while (count > 1)  
        {  
            count--;  
              
            int rnd = random.Next(count + 1);  
              
            T value = list[rnd];  
            list[rnd] = list[count];  
            list[count] = value;  
        }  
    }  
}  

Get the files

public class FileOperations  
{  
      
    public static List<FileItem> GetFilesFromPath(string folderName, string extension = "*.*") =>  
        Directory.GetFiles(folderName, extension).Select(file => new FileItem()  
        {  
            FileName = Path.GetFileName(file),   
            FolderName = folderName  
        }).ToList();  
}  

Form code which load files into a list then assign to a BindingSource. Once loaded, we select a file then mark it as selected rather than delete it.

public partial class Form1 : Form  
{  
    private readonly BindingSource _bindingSource = new BindingSource();  
    public Form1()  
    {  
        InitializeComponent();  
        SelectButton.Enabled = false;  
        label1.Text = "";  
    }  
      
    private void SelectButton_Click(object sender, EventArgs e)  
    {  
        var fileItemsList = ((List<FileItem>) _bindingSource.DataSource);  
          
        fileItemsList.Shuffle();  
          
        var fileItem = fileItemsList.FirstOrDefault(item => item.Selected == false);  
        if (fileItem != null)  
        {  
            fileItem.Selected = true;  
            listBox1.Items.Add(fileItem.FileName);  
        }  
  
  
        var count = fileItemsList.Count(item => item.Selected == false);  
  
        label1.Text = $"{count} not select of {fileItemsList.Count}";  
  
        if (count != 0) return;  
        SelectButton.Enabled = false;  
        LoadButton.Enabled = true;  
  
    }  
  
    private void LoadButton_Click(object sender, EventArgs e)  
    {  
        string folderName = "TODO";  
  
        if (!Directory.Exists(folderName)) return;  
          
        listBox1.Items.Clear();  
        label1.Text = "";  
  
        SelectButton.Enabled = true;  
  
        _bindingSource.DataSource = FileOperations.GetFilesFromPath(folderName);  
  
        LoadButton.Enabled = false;  
    }  
}  

Answer 2

Try something like this:

Random rand = new Random( );
List<string> files = Directory.GetFiles( "Select Directory" ).ToList( );
if( files.Count > 0 )
{
    int i = rand.Next( files.Count );
    string randomFile = files[i];
    files.RemoveAt( i );
    // . . .
}

// next time:
if( files.Count > 0 )
{
    int i = rand.Next( files.Count );
    string randomFile = files[i];
    files.RemoveAt( i );
    // . . .
}