Display Size in reeadble format

GetSizeReadable.cs

public static string GetSizeReadable(long i)
{
    string sign = (i < 0 ? "-" : "");
    double readable = (i < 0 ? -i : i);
    string suffix;
    if (i >= 0x1000000000000000) // Exabyte
    {
        suffix = "EB";
        readable = (double)(i >> 50);
    }
    else if (i >= 0x4000000000000) // Petabyte
    {
        suffix = "PB";
        readable = (double)(i >> 40);
    }
    else if (i >= 0x10000000000) // Terabyte
    {
        suffix = "TB";
        readable = (double)(i >> 30);
    }
    else if (i >= 0x40000000) // Gigabyte
    {
        suffix = "GB";
        readable = (double)(i >> 20);
    }
    else if (i >= 0x100000) // Megabyte
    {
        suffix = "MB";
        readable = (double)(i >> 10);
    }
    else if (i >= 0x400) // Kilobyte
    {
        suffix = "KB";
        readable = (double)i;
    }
    else
    {
        return i.ToString(sign + "0 B"); // Byte
    }
    readable = readable / 1024;

    return sign + readable.ToString("0.### ") + suffix;
}