步步为营 .NET三层架构解析 四、Model设计(四种设计方式)

说到Model设计,我们先谈谈它的作用:

    Model又叫实体类，model层里面的一个类对应数据库里面的一张表， 类里面的每一个属性对应表里面的一个字段，每个属性都有自己的 GET 和 SET 方法， 项目中的数据存取都要依靠GET和SET方法来实现.确切的说它不属于纵向的哪一层，而是所有层都要用到的业务实体层。其实最主要的作用还是用来传递参数.

下面我就用四种方式来创建Model类:
方式一：
    创建department的实体类department.cs:

   public class department
    {
       private int _id;
       private string _departname;
       private string _description;
       public int id
       {
           set { _id = value; }
           get { return _id; }
       }
       public string departname
       {
           set { _departname = value; }
           get { return _departname; }
       }
       public string description
       {
           set { _description = value; }
           get { return _description; }
       }
    }

再来创建custom的实体类custom.cs:

   public class custom
    {
       private int _id;
       private string _cname;
       private string _ename;
       private int _departID;
       private int _age;
       private string _password;
       private string _departname;
       public string departname
       {
           set { _departname = value; }
           get { return _departname; }
       }
       public int id
       {
           set { _id = value; }
           get { return _id; }
       }
       public string cname
       {
           set { _cname = value; }
           get { return _cname; }
       }
       public string ename
       {
           set { _ename = value; }
           get { return _ename; }
       }
       public int departID
       {
           set { _departID = value; }
           get { return _departID; }
       }
       public int age
       {
           set { _age = value; }
           get { return _age; }
       }
       public string password
       {
           set { _password = value; }
           get { return _password; }
       }
    }

实体类我们就建好了,其实也有一种更简化方式,效果和上面是一样的:

方式二：

department.cs

   public class department
    {
       public int id
       {
           set ;
           get;
       }
       public string departname
       {
           set ;
           get ;
       }
       public string description
       {
           set;
           get ;
       }
    }

custom.cs:

   public class custom
    {
       public string departname
       {
           set ;
           get;
       }
       public int id
       {
           set ;
           get;
       }
       public string cname
       {
           set ;
           get;
       }
       public string ename
       {
           set;
           get ;
       }
       public int departID
       {
           set;
           get ;
       }
       public int age
       {
           set;
           get;
       }
       public string password
       {
           set ;
           get;
       }
    }

也可采用如下这种方式创建:

方式三：

custom.cs:

    public class custom
    {
        private int _id;
        private string _cname;
        private string _ename;
        private int _departID;
        private int _age;
        private string _password;
        private string _departname;
        public string departname
        {
            get { return _departname; }
        }
        public int id
        {
            get { return _id; }
        }
        public string cname
        {
            get { return _cname; }
        }
        public string ename
        {
            get { return _ename; }
        }
        public int departID
        {
            get { return _departID; }
        }
        public int age
        {
            get { return _age; }
        }
        public string password
        {
            get { return _password; }
        }
        public custom(int ID,string DepartName,string CName,string EName,int DepartID,int Age,string PassWord )
        {
            _id = ID;
            _departname = DepartName;
            _cname = CName;
            _ename = EName;
            _departID = DepartID;
            _age = Age;
            _password = PassWord;
        }
    }

department.cs:

    public class department
    {
        private int _id;
        private string _departname;
        private string _description;
        public int id
        {
            set { _id = value; }
        }
        public string departname
        {
            set { _departname = value; }
        }
        public string description
        {
            set { _description = value; }
        }
        public department(int ID,string DepartName,string Description)
        {
            _id = ID;
            _departname = DepartName;
            _description = Description;
        }
    }

还有一种方式就是结合方式一和方式三来设计

方式四:

custom.cs:

    public class custom
    {
        private int _id;
        private string _cname;
        private string _ename;
        private int _departID;
        private int _age;
        private string _password;
        private string _departname;
        public string departname
        {
            set { _departname = value; }
            get { return _departname; }
        }
        public int id
        {
            set { _id = value; }
            get { return _id; }
        }
        public string cname
        {
            set { _cname = value; }
            get { return _cname; }
        }
        public string ename
        {
            set { _ename = value; }
            get { return _ename; }
        }
        public int departID
        {
            set { _departID = value; }
            get { return _departID; }
        }
        public int age
        {
            set { _age = value; }
            get { return _age; }
        }
        public string password
        {
            set { _password = value; }
            get { return _password; }
        }
        public custom()
        { }
        public custom(int ID, string DepartName, string CName, string EName, int DepartID, int Age, string PassWord)
        {
            _id = ID;
            _departname = DepartName;
            _cname = CName;
            _ename = EName;
            _departID = DepartID;
            _age = Age;
            _password = PassWord;
        }
    }

department.cs:

    public class department
    {
        private int _id;
        private string _departname;
        private string _description;
        public int id
        {
            set { _id = value; }
            get { return _id; }
        }
        public string departname
        {
            set { _departname = value; }
            get { return _departname; }
        }
        public string description
        {
            set { _description = value; }
            get { return _description; }
        }
        public department()
        { }
        public department(int ID, string DepartName, string Description)
        {
            _id = ID;
            _departname = DepartName;
            _description = Description;
        }
    }

方式三的赋值和方式一 方式二是不同的。我们采用的是方式一来设计。

其种各种方式的优缺点我就不讲了,代码己说明很清楚了.

Model类建好了,我们就要开始创建DAL类库了,这是三层架构中的核心部分,下回分解,敬请拍砖.