SHA-1 Calculator WPF (C#+WPF) / http://inaz2.hatenablog.com/entry/2016/05/02/010051

MainWindow.xaml

<Window x:Class="SHA1CalculatorWPF.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:SHA1CalculatorWPF"
        mc:Ignorable="d"
        Title="SHA-1 Calculator WPF" Height="350" Width="640">
    <Grid AllowDrop="True" DragOver="Grid_DragOver" Drop="Grid_Drop">
        <DataGrid x:Name="dataGrid" AutoGenerateColumns="False" CanUserResizeRows="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="File Path" Binding="{Binding Path}" Width="*"/>
                <DataGridTextColumn Header="sha1sum" Binding="{Binding Sha1sum}" Width="*"/>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

MainWindow.xaml.cs

using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.IO;
using System.Runtime.CompilerServices;
using System.Windows;

namespace SHA1CalculatorWPF
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        ObservableCollection<FileInfo> fileList;

        public class FileInfo : INotifyPropertyChanged
        {
            public event PropertyChangedEventHandler PropertyChanged;
            private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }

            public string Path { get; set; }

            private string _sha1sum;
            public string Sha1sum
            {
                get { return _sha1sum; }
                set
                {
                    if (value != _sha1sum)
                    {
                        _sha1sum = value;
                        NotifyPropertyChanged();
                    }
                }
            }
        }

        public MainWindow()
        {
            InitializeComponent();

            fileList = new ObservableCollection<FileInfo>();
            dataGrid.ItemsSource = fileList;
        }

        private void Grid_DragOver(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                e.Effects = DragDropEffects.Copy;
            }
            else
            {
                e.Effects = DragDropEffects.None;
            }
            e.Handled = false;
        }

        private void Grid_Drop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                var paths = (string[])e.Data.GetData(DataFormats.FileDrop);
                foreach (var path in paths)
                {
                    var fileinfo = new FileInfo { Path = path, Sha1sum = "" };
                    fileList.Add(fileinfo);
                    var worker = new BackgroundWorker();
                    worker.DoWork += worker_DoWork;
                    worker.RunWorkerAsync(fileinfo);
                }
            }
        }

        void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            // update digest with each 8MB chunk
            var fileinfo = (FileInfo)e.Argument;
            var fs = new FileStream(fileinfo.Path, FileMode.Open, FileAccess.Read);
            var sha1 = new System.Security.Cryptography.SHA1Managed();
            var buf = new byte[8 * 1024 * 1024];
            int n = fs.Read(buf, 0, buf.Length);
            while (fs.Position < fs.Length)
            {
                sha1.TransformBlock(buf, 0, n, buf, 0);
                fileinfo.Sha1sum = string.Format("Calculating {0}%...", 100L * fs.Position / fs.Length);
                n = fs.Read(buf, 0, buf.Length);
            }
            sha1.TransformFinalBlock(buf, 0, n);
            fileinfo.Sha1sum = BitConverter.ToString(sha1.Hash).Replace("-", "").ToLower();
        }
    }
}

SHA1CalculatorWPF.exe