C＃MD5散列器的例子 [英] C# MD5 hasher example

问题描述

编辑：我改名这为code按预期工作为例

I've retitled this to an example as the code works as expected.

我试图复制一个文件，得到一个MD5哈希值，然后删除该副本。我这样做是为了避免对原文件，另一个应用程序写入过程锁。但是，我越来越对我复制的文件锁定。

I am trying to copy a file, get a MD5 hash, then delete the copy. I am doing this to avoid process locks on the original file, which another app writes to. However, I am getting a lock on the file I've copied.

File.Copy(pathSrc, pathDest, true);

String md5Result;
StringBuilder sb = new StringBuilder();
MD5 md5Hasher = MD5.Create();

using (FileStream fs = File.OpenRead(pathDest))
{
    foreach(Byte b in md5Hasher.ComputeHash(fs))
        sb.Append(b.ToString("x2").ToLower());
}

md5Result = sb.ToString();

File.Delete(pathDest);

我然后得到一个进程无法访问文件'关于 File.Delete异常（）。

我期望与使用声明中，文件流将很好地关闭。我也曾尝试单独声明文件流，删除使用，并把 fs.Close（）和 fs.Dispose（）读了。

I would expect that with the using statement, the filestream would be closed nicely. I have also tried declaring the filestream separately, removing using, and putting fs.Close() and fs.Dispose() after the read.

在此之后，我注释掉实际MD5计算，和code excutes，文件被删除，所以它看起来像它的东西做 ComputeHash（FS）。

After this, I commented out the actually md5 computation, and the code excutes, with the file being deleted, so it looks like it's something to do with ComputeHash(fs).

推荐答案

我把你的code把它在一个控制台应用程序并没有错误运行它时，得到了哈希和测试文件是在结束时删除执行？我只是用.PDB从我的测试应用程序的文件。

I took your code put it in a console app and ran it with no errors, got the hash and the test file is deleted at the end of execution? I just used the .pdb from my test app as the file.

您运行的是什么版本的.NET的？

What version of .NET are you running?

我把code，我有一个在这里工作，如果你把这个在一个控制台应用程序在VS2008 .NET 3.5 SP1它不出差错运行（至少对我来说）。

I am putting the code that I have that works here, and if you put this in a console app in VS2008 .NET 3.5 sp1 it runs with no errors (at least for me).

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace lockTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string hash = GetHash("lockTest.pdb");

            Console.WriteLine("Hash: {0}", hash);

            Console.ReadKey();
        }

        public static string GetHash(string pathSrc)
        {
            string pathDest = "copy_" + pathSrc;

            File.Copy(pathSrc, pathDest, true);

            String md5Result;
            StringBuilder sb = new StringBuilder();
            MD5 md5Hasher = MD5.Create();

            using (FileStream fs = File.OpenRead(pathDest))
            {
                foreach (Byte b in md5Hasher.ComputeHash(fs))
                    sb.Append(b.ToString("x2").ToLower());
            }

            md5Result = sb.ToString();

            File.Delete(pathDest);

            return md5Result;
        }
    }
}

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