/// <summary>
    /// 找出实体被修改盗字段
    /// </summary>
    public class FindPropertiesChanged
    {
        /// <summary>
        /// 找出实体被修改盗字段
        /// </summary>
        /// <param name="before">修改前实体</param>
        /// <param name="after">修改后实体</param>
        /// <returns>修改内容</returns>
        public static String Find(object before,object after)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("");
            PropertyInfo[] beforepropertys = before.GetType().GetProperties();
            PropertyInfo[] afterpropertys = after.GetType().GetProperties();

            //linq的方式
            var post = afterpropertys.Where(s => s.GetValue(after) != null);
            foreach(var a in post)
            {
                var changed = beforepropertys.Where(s => s.Name == a.Name && s.GetValue(before) != null && s.GetValue(before) != a.GetValue(after)).FirstOrDefault();
                if (changed!=null)
                {
                    //修改记录
　　　　　　　　　　　　sb.Append(changed.Name + ":" + changed.GetValue(before) + "->" + a.Name + ":" + a.GetValue(after) + "；");
                }
            }

            return sb.ToString();
        }
    }