using System;
using System.Security.Cryptography;
using System.Text;

public class Util
{
    /// <summary>
    /// 转换方法
    /// </summary>
    /// <param name="size">字节值</param>
    /// <returns></returns>
    public static string HumanReadableFilesize(double size)
    {
        String[] units = new String[] { "B", "KB", "MB", "GB", "TB", "PB" };
        double mod = 1024.0;
        int i = 0;
        while (size >= mod)
        {
            size /= mod;
            i++;
        }
        int littleNum = 0;//取几位小数
        if (i == 0 || i == 1)
            littleNum = 0;
        else
            littleNum = 2;

        return Math.Round(size, littleNum) + units[i];
    }

    /// <summary>
    /// MD5Encrypt
    /// </summary>
    /// <param name="str"></param>
    /// <returns></returns>
    public static string MD5Encrypt(string str)
    {
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        byte[] bytes = Encoding.ASCII.GetBytes(str);
        byte[] encoded = md5.ComputeHash(bytes);
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++)
        {
            sb.Append(encoded[i].ToString("x2"));
        }
        string str1 = sb.ToString();
        str1 = str1.Substring(0, 10);
        return str1;
    }


    public static string changTime(double size)
    {
        DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
        DateTime dt = startTime.AddSeconds(size);
        //string t = dt.ToString("yyyy/MM/dd HH:mm:ss");
        string t = dt.ToString("yyyy/MM/dd");
        return t;
    }
}