how permadelet works 2 https://devstree.io/how-permadelete-works-2/

1.cs

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>

    <StackPanel Orientation="Horizontal" VerticalAlignment="Bottom" HorizontalAlignment="Center">
        <TextBlock Text="File Name: " FontSize="24"/>
        <TextBox x:Name="txtFileName" Width="280" FontSize="18"/>
    </StackPanel>

    <Button x:Name="buttonShred" Content="Shred" FontSize="24" Padding="30, 15" HorizontalAlignment="Center"
            VerticalAlignment="Center" Grid.Row="1" Click="buttonShred_Click" />
</Grid>

2.cs

using System;
using System.IO;

namespace FileShredder
{
    public class Shredder
    {
        private const int MAX_BUFFER_SIZE = 1024 * 1024; // One Megabyte
        static private Random _random = new Random(); // Used to get random numbers to replace over the original file data
        
        // The rest of the class goes here...
    }
}

3.cs

private static void OverWriteFile(FileInfo file)
{
    // 1. Open a stream from the file
    using (var stream = new FileStream(file.FullName, FileMode.Open, FileAccess.Write, FileShare.None))
    {
        // 2. Generate random numbers and store them in an array
        var buffer = new byte[MAX_BUFFER_SIZE];

       
        for (int i = 0; i < MAX_BUFFER_SIZE; i++)
        {
            // Random numbers are from 0 to 255. because each of them replace a byte of the file.
            buffer[i] = (byte)_random.Next(0, 255);
        }

        // 3. Now replace the file's actual content with the array of random numbers
        for (var length = file.Length; length > 0; length -= MAX_BUFFER_SIZE)
        {
            // Make sure we don't write more bytes than the file size
            int bytesToWrite = (length > MAX_BUFFER_SIZE) ? MAX_BUFFER_SIZE : (int)length;

            // Write the whole buffer over the file
            stream.Write(buffer, 0, bytesToWrite);

            // Flush as soon as possible. To make sure that the file is overwritten
            stream.Flush();
        }

        // 4. Set file size to 0
        stream.SetLength(0);
    }
}

4.cs

private static void DestroyFileMetadata(FileInfo file)
{
    // 1. Get the folder name that has the file
    var directoryName = Path.GetDirectoryName(file.FullName);

    // 2. Rename the file 5 times to remove it from the file system table.
    for (var round = 0; round < 5; round++)
    {
        var newPath = Path.Combine(directoryName, Path.GetRandomFileName());
        file.MoveTo(newPath);
    }

    // 3. Set all of the dates of the to Jan 1st 2000.
    var newTime = new DateTime(2000, 1, 1, 0, 0, 1);
    file.LastWriteTime = newTime;
    file.CreationTime = newTime;
    file.LastAccessTime = newTime;
}

5.cs

public static void ShredFile(string path)
{
    // 1. Make sure the file exists
    if (!File.Exists(path))
        throw new ArgumentException("The file does not exist: " + path);

    // 2. Get the file info
    FileInfo file = new FileInfo(path);

    // 3. Shred the file
    OverWriteFile(file);
    DestroyFileMetadata(file);
    File.Delete(path);
}

6.cs

private void buttonShred_Click(object sender, RoutedEventArgs e)
{
    try
    {
        Shredder.ShredFile(txtFileName.Text);
        MessageBox.Show("The file was shredded successfuly!", "Success!");
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "There was an error", MessageBoxButton.OK, MessageBoxImage.Error);
    }
}