C# 获取电脑硬盘剩余空间

public DiskList DisklistCon(string disk)
        {
            DiskList dl = new DiskList();
            string[] diskcon = null;
            dl.msgList = new List<DiskCon>();
            dl.msg = "成功！";
            if (!string.IsNullOrEmpty(disk))
            {
                DriveInfo di = new DriveInfo(disk);
                DiskCon dk = new DiskCon();
                dk.DiskName = disk;
                dk.DiskLength = di.AvailableFreeSpace;
                dl.msgList.Add(dk);
                dl.count = 1;
            }
            else
            {
                try
                {
                    diskcon = Directory.GetLogicalDrives();
                }
                catch { }
                if (diskcon != null && diskcon.Count() > 0)
                {
                    foreach (string diskname in diskcon)
                    {
                        DriveInfo di = new DriveInfo(diskname);
                        DiskCon dk = new DiskCon();
                        dk.DiskName = diskname;
                        dk.DiskLength = di.AvailableFreeSpace;
                        dl.msgList.Add(dk);
                    }
                    dl.count = diskcon.Count();
                }
            }

            return dl;
        }

 public class DiskList
    {
        public string msg { get; set; }
        public List<DiskCon> msgList { get; set; }
        public int count { get; set; }
    }
    public class DiskCon
    {
        public string DiskName { get; set; }
        public long DiskLength { get; set; }
        public string DiskGb
        {
            get
            {
                return (DiskLength * 1.0 / 1024 / 1024 / 1024).ToString("0.00GB");
            }
        }
    }