C# 计算文件大小（B/KB/MB/GB）

递归法

        public  long GetLength(double data, int i, out int index)
        {
            index = i;
            long temp = (long )(data / 1024);
            while (temp > 1024)
            {
                i++;
                temp = GetLength(temp, i, out index);
            }
            return temp;

        }

        public string ConvertDiskSpace(long  res, int index)
        {
            string diskSize = "";
            switch (index)
            {

                case 0:
                    diskSize = $"{res.ToString("0.00")}B";
                    break;
                case 1:
                    diskSize = $"{res.ToString("0.00")}KB";
                    break;
                case 2:
                    diskSize = $"{res.ToString("0.00")}MB";
                    break;
                case 3:
                    diskSize = $"{res.ToString("0.00")}GB";
                    break;
                case 4:
                    diskSize = $"{res.ToString("0.00")}TB";
                    break;
                default:
                    break;
            }
            return diskSize;
        }