Linq 实现两个对象实例List之间的赋值

 public class UserCopy
 {
     public class LoginEntity
     {
         public string UserName { get; set; }
         public string UserPwd { get; set; }
         public DateTime ActiveTime { get; set; }
     }

     public class UserEntity : LoginEntity
     {
         public string UserID { get; set; }
         public Int16 UserSex { get; set; }
         public Int32 UserAge { get; set; }
     }

     protected void UserCopy()
     {
         List<UserEntity> userList = new List<UserEntity>() {
             new UserEntity(){
             UserID="U1",
             UserName="U1",
             UserPwd="U1PWD",
             ActiveTime=DateTime.Now
             },
             new UserEntity(){
             UserID="U2",
             UserName="U2",
             UserPwd="U2PWD",
             ActiveTime=DateTime.Now},
             new UserEntity(){
             UserID="U2",
             UserName="U2",
             UserPwd="U2PWD",
             ActiveTime=DateTime.Now}
             };

         List<LoginEntity> loginList = new List<LoginEntity>();
         //关键代码：遍历赋值
         userList.ForEach(user => loginList.Add(new LoginEntity()
         {
             UserName = user.UserName,
             UserPwd = user.UserPwd,
             ActiveTime = user.ActiveTime
         }));
     }
 }