属性的基本语法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CSGDemo.CSG021
{
    //https://docs.microsoft.com/zh-cn/dotnet/csharp/properties


    class CSG021Property
    {
        //#csg021-01，声明方式一，最传统方式
        private string _property1;

        public string Property1
        {
            get { return _property1; }
            set { _property1 = value; }
        }


        //#csg021-02，声明方式二，自动属性
        public string Property2 { get; set; }


        //#csg021-03，声明方式三，默认属性
        public string Property3 { get; set; } = "default value";


        //#csg021-04，声明方式四，带修饰符的访问器
        public string Property4 { get; private set; }


        //#csg021-05，声明方式五，使用init关键字
        //init 关键字的含义为 该属性只能在构造函数中被赋值。
        public string Property5 { get; init; }


        //#csg021-06，声明方式五，带 expression-bodied 语法访问器
        private string _property6;
        public string Property6
        {
            get => _property6;
            set => _property6 = value;
        }

    }





    //#csg021-07，属性改变事件 INotifyPropertyChanged
    //该接口用于通知数据绑定客户端值已更改 
    public class Person : INotifyPropertyChanged
    {
        private string _firstName;
        public string FirstName
        {
            get => _firstName;
            set
            {
                if (string.IsNullOrWhiteSpace(value))
                    throw new ArgumentException("First name must not be blank");
                if (value != _firstName)
                {
                    PropertyChanged?.Invoke(this,new PropertyChangedEventArgs(nameof(FirstName)));
                }
                _firstName = value;
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

}