反射解决类的复制

      假定一个类，类名是EtyBase，另一个类类名是EtyTwo，EtyTwo继承自EtyBase。现在要求EtyTwo的属性值从一个EtyBase中复制过来传统做法是

        public void CopyEty(EtyBase from, EtyBase to)
        {
            to.AccStatus = from.AccStatus;
            to.Alarm = from.Alarm;
            to.AlarmType = from.AlarmType;
            to.CarNum = from.CarNum;
            to.DevNum = from.DevNum;
            to.DeviceNum = from.DeviceNum;
            to.Direct = from.Direct;
            to.DriveCode = from.DriveCode;
            to.GpsData = from.GpsData;
            to.GpsEnvent = from.GpsEnvent;
            to.GpsOdo = from.GpsOdo;
            to.GpsSpeed = from.GpsSpeed;
            to.GpsStatus = from.GpsStatus;
            to.GpsrevTime = from.GpsrevTime;
            to.Gsmci = from.Gsmci;
            to.Gsmci1 = from.Gsmci1;
            to.Gsmloc = from.Gsmloc;
            to.Gsmloc1 = from.Gsmloc1;
            to.IsEffective = from.IsEffective;
            to.IsJump = from.IsJump;
            to.IsReply = from.IsReply;
            to.Latitude = from.Latitude;
            to.LaunchStatus = from.LaunchStatus;
            to.Longitude = from.Longitude;
            to.MsgContent = from.MsgContent;
            to.MsgExId = from.MsgExId;
            to.MsgId = from.MsgId;
            to.MsgLength = from.MsgLength;
            to.MsgType = from.MsgType;
            to.NowOverArea = from.NowOverArea;
            to.NowStatus = from.NowStatus;
            to.Oil = from.Oil;
            to.PulseCount = from.PulseCount;
            to.PulseOdo = from.PulseOdo;
            to.PulseSpeed = from.PulseSpeed;
            to.ReplyContent = from.ReplyContent;
            to.RevMsg = from.RevMsg;
            to.Speed = from.Speed;
            to.Status = from.Status;
            to.Temperture = from.Temperture;
            to.UserName = from.UserName;
        }

      这样子做有几点不好的地方

1. EtyBase的属性改变时复制的属性也得改变，耦合较高；
2. 若EtyBase的属性比较多，那么这个复制方法将显得比较冗长，写的人手累。

      如果用反射来做，我是这么做的

        public void CopyEty(EtyBase from, EtyBase to)
        {
            //利用反射获得类成员
            FieldInfo[] fieldFroms = from.GetType().GetFields();
            FieldInfo[] fieldTos = to.GetType().GetFields();
            int lenTo = fieldTos.Length;

            for (int i = 0, l = fieldFroms.Length; i < l; i++)
            {
                for (int j = 0; j < lenTo; j++)
                {
                    if (fieldTos[j].Name != fieldFroms[i].Name) continue;
                    fieldTos[j].SetValue(to, fieldFroms[i].GetValue(from));
                    break;
                }
            }
        }

      反射可以解决上述的两个缺点，当类属性改变或增加时，此复制方法无需改变。当然这是要付出些许运行效率的。