الخصائص الكاملة مع الحقول الداعمة

ما بعد الخصائص التلقائية

using System;

class Temperature
{
    private double _celsius;

    public double Celsius
    {
        get { return _celsius; }
        set { _celsius = value; }
    }
}

class Program
{
    static void Main()
    {
        var t = new Temperature();
        t.Celsius = 21.5;
        Console.WriteLine(t.Celsius);
    }
}

اصطلاح تسمية حقل الإسناد

using System;

class Person
{
    private string _name;

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }
}

class Program
{
    static void Main()
    {
        var p = new Person();
        p.Name = "Grace";
        Console.WriteLine(p.Name);
    }
}

الكلمة الأساسية value

using System;

class Box
{
    private int _size;

    public int Size
    {
        get { return _size; }
        set { _size = value * 2; }
    }
}

class Program
{
    static void Main()
    {
        var box = new Box();
        box.Size = 10;
        Console.WriteLine("Stored size: " + box.Size);
    }
}

التحقق من الصحة في دالة الإسناد

using System;

class Account
{
    private decimal _balance;

    public decimal Balance
    {
        get { return _balance; }
        set
        {
            if (value < 0)
                throw new ArgumentException("Balance cannot be negative");
            _balance = value;
        }
    }
}

class Program
{
    static void Main()
    {
        var a = new Account();
        a.Balance = 500m;
        Console.WriteLine("Balance: " + a.Balance);
    }
}

الخصائص المحسوبة للقراءة فقط

using System;

class Rectangle
{
    private double _width;
    private double _height;

    public Rectangle(double w, double h)
    {
        _width = w;
        _height = h;
    }

    public double Area
    {
        get { return _width * _height; }
    }
}

class Program
{
    static void Main()
    {
        var r = new Rectangle(4, 5);
        Console.WriteLine("Area: " + r.Area);
    }
}

الآثار الجانبية في دوال الإسناد

using System;

class User
{
    private string _email;

    public string Email
    {
        get { return _email; }
        set { _email = value.Trim().ToLower(); }
    }
}

class Program
{
    static void Main()
    {
        var u = new User();
        u.Email = "  Hello@Example.COM  ";
        Console.WriteLine("Normalized: " + u.Email);
    }
}

الحساب الكسول في دالة الوصول

using System;

class Report
{
    private string _cached;

    public string Content
    {
        get
        {
            if (_cached == null)
                _cached = "Generated at runtime";
            return _cached;
        }
    }
}

class Program
{
    static void Main()
    {
        var r = new Report();
        Console.WriteLine(r.Content);
        Console.WriteLine(r.Content);
    }
}

الحماية من الحالة غير الصالحة

using System;

class Volume
{
    private int _level;

    public int Level
    {
        get { return _level; }
        set
        {
            if (value < 0) _level = 0;
            else if (value > 100) _level = 100;
            else _level = value;
        }
    }
}

class Program
{
    static void Main()
    {
        var v = new Volume();
        v.Level = 150;
        Console.WriteLine("Clamped: " + v.Level);
    }
}

دمج القيم المخزنة والمحسوبة

using System;

class Employee
{
    private string _first;
    private string _last;

    public string First { get { return _first; } set { _first = value; } }
    public string Last { get { return _last; } set { _last = value; } }
    public string FullName { get { return _first + " " + _last; } }
}

class Program
{
    static void Main()
    {
        var e = new Employee { First = "Marie", Last = "Curie" };
        Console.WriteLine(e.FullName);
    }
}

إطلاق إشعارات التغيير

using System;

class Model
{
    private int _count;

    public int Count
    {
        get { return _count; }
        set
        {
            if (_count != value)
            {
                _count = value;
                Console.WriteLine("Count changed to " + _count);
            }
        }
    }
}

class Program
{
    static void Main()
    {
        var m = new Model();
        m.Count = 1;
        m.Count = 1;
        m.Count = 2;
    }
}

جمع العناصر معًا

using System;

class Thermostat
{
    private double _target;

    public double Target
    {
        get { return _target; }
        set { _target = value < 10 ? 10 : value; }
    }

    public string Status { get { return _target >= 22 ? "Warm" : "Cool"; } }
}

class Program
{
    static void Main()
    {
        var th = new Thermostat();
        th.Target = 5;
        Console.WriteLine(th.Target + " -> " + th.Status);
        th.Target = 24;
        Console.WriteLine(th.Target + " -> " + th.Status);
    }
}

تحقق سريع

مراجعة

using System;

class Demo
{
    private int _n;
    public int N
    {
        get { return _n; }
        set { _n = value < 0 ? 0 : value; }
    }
    public int Doubled { get { return _n * 2; } }
}

class Program
{
    static void Main()
    {
        var d = new Demo();
        d.N = -5;
        Console.WriteLine(d.N + ", " + d.Doubled);
    }
}