C#统计目录中文件MD5值，并存入剪贴板中

C#统计目录中文件MD5值，并存入剪贴板中

using System.IO;
using System.Security.Cryptography;
using System.Collections;
using System.Windows.Forms;
 IDataObject iData = Clipboard.GetDataObject();
   if (iData.GetDataPresent(DataFormats.Text))
   {
string filepath=(string)iData.GetData(DataFormats.Text);
StringBuilder sbMD5= new StringBuilder(1024);
string filepath=@"C:\tmp";
DirectoryInfo dir = new DirectoryInfo((filepath.LastIndexOf(Path.DirectorySeparatorChar) == filepath.Length - 1) ? filepath : filepath + Path.DirectorySeparatorChar);
FileSystemInfo[] fileArr = dir.GetFileSystemInfos();
Queue<FileSystemInfo> Folders = new Queue<FileSystemInfo>(dir.GetFileSystemInfos());
while (Folders.Count > 0)
{
    FileSystemInfo atom = Folders.Dequeue();
    FileInfo f = atom as FileInfo;
    if (f == null)
    {
        DirectoryInfo d = atom as DirectoryInfo;
        foreach (FileSystemInfo fi in d.GetFileSystemInfos())
            Folders.Enqueue(fi);
    }
    else
    {
        FileStream fs = new FileStream(f.FullName,FileMode.Open,FileAccess.Read);
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        byte [] md5byte = md5.ComputeHash(fs);
        int i,j;
        StringBuilder sb = new StringBuilder(16);
        foreach (byte b in md5byte)
        {
        　   i = Convert.ToInt32(b);
        　　 j = i >> 4;
        　　 sb.Append(Convert.ToString(j,16));
        　　 j = ((i << 4) & 0x00ff) >> 4;
        　　 sb.Append(Convert.ToString(j,16));
        }
        sbMD5.Append(f.FullName);
        sbMD5.Append("\t");
        sbMD5.Append(sb.ToString());
        sbMD5.Append("\r\n");
    }
}
Clipboard.SetText(sbMD5.ToString());
   }
   else
    MessageBox.Show("目前剪贴板中数据不可转换为文本","错误");