VCS/HashChecker - Sample is best!

開発環境	Microsoft Visual C# 2010 Express (SP1)
実行環境	Microsoft Windows XP Home Edition (SP3)
プロジェクトの種類	Windows フォーム アプリケーション
プロジェクト名	HashChecker

プロパティ

Form1	AcceptButton	Check
	AllowDrop	True
	MaximizeBox	False
	Text	Hash Checker
Label	Text	File Path
TextBox	(Name)	FilePath
	Enabled	False
Label	Text	MD5
TextBox	(Name)	MD5Out
	Enabled	False
TextBox	(Name)	MD5In
Label	Text	SHA-1
TextBox	(Name)	SHA1Out
	Enabled	False
TextBox	(Name)	SHA1In
Label	Text	File Size
TextBox	(Name)	FileSizeOut
	Enabled	False
TextBox	(Name)	FileSizeIn
Button	(Name)	Check
	Text	Check

参考

• ファイルのMD5やSHA1などでハッシュ値を計算する: .NET Tips: C#, VB.NET

Form1.cs

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;
 
namespace HashChecker
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
            {
                e.Effect = DragDropEffects.Copy;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }
 
        private void Form1_DragDrop(object sender, DragEventArgs e)
        {
            string[] filePathArray = (string[])e.Data.GetData(DataFormats.FileDrop, false);
            string filePath = filePathArray[0];
            FilePath.Text = filePath;
 
            // File Size
            FileInfo fi = new FileInfo(filePath);
            FileSizeOut.Text = fi.Length.ToString();
 
            FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
 
            // MD5
            using (MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider())
            {
                byte[] bs = md5.ComputeHash(fs);
                StringBuilder result = new StringBuilder();
                foreach (byte b in bs)
                {
                    result.Append(b.ToString("x2"));
                }
                MD5Out.Text = result.ToString();
            }
            fs.Seek(0, SeekOrigin.Begin);
 
            // SHA-1
            using (SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider())
            {
                byte[] bs = sha1.ComputeHash(fs);
                StringBuilder result = new StringBuilder();
                foreach (byte b in bs)
                {
                    result.Append(b.ToString("x2"));
                }
                SHA1Out.Text = result.ToString();
            }
            fs.Close();
        }
 
        private void Check_Click(object sender, EventArgs e)
        {
            StringBuilder message = new StringBuilder();
            int error = 0;
 
            // File Size
            message.Append("File Size: ");
            string fileSize = FileSizeIn.Text.Replace(",", "");
            if (FileSizeOut.Text == fileSize)
            {
                message.Append("OK");
            }
            else
            {
                message.Append("NG");
                error++;
            }
 
            // MD5
            message.Append("\nMD5: ");
            if (String.Compare(MD5Out.Text, MD5In.Text, true) == 0)
            {
                message.Append("OK");
            }
            else
            {
                message.Append("NG");
                error++;
            }
 
            // SHA-1
            message.Append("\nSHA-1: ");
            if (String.Compare(SHA1Out.Text, SHA1In.Text, true) == 0)
            {
                message.Append("OK");
            }
            else
            {
                message.Append("NG");
                error++;
            }
 
            MessageBoxIcon icon;
            switch (error)
            {
                case 0:
                    icon = MessageBoxIcon.Information;
                    break;
                case 3:
                    icon = MessageBoxIcon.Error;
                    break;
                default:
                    icon = MessageBoxIcon.Warning;
                    break;
            }
            MessageBox.Show(message.ToString(), "Hash Checker", MessageBoxButtons.OK, icon);
        }
    }
}