设计模式- 建造者模式(Builder Pattern)

    public class People
    {
        private readonly string _profession;
        private readonly string _name;
        private string _hairType;
        private string _hairColor;

        public People(Builder builder)
        {
            this._profession = builder.Profession;
            this._name = builder.Name;
            this._hairColor = builder.HairColor??"黑";
            this._hairType = builder.HairType??"短发";
        }
        public string Show() {
            return string.Format("这个人的名字是{1}，职业是{0}，有一头{2}色的{3}",_profession,_name,_hairColor,_hairType);
        }
    }

    public sealed  class Builder
    {
        public string Profession { get; private set; }
        public string Name { get; private set; }
        public string HairType { get; private set; }
        public string HairColor { get; private set; }
        public Builder(string profession, string name)
        {
            if (profession == null || name == null)
            {
                throw new Exception("profession 和 name 不能为空");
            }
            this.Profession = profession;
            this.Name = name;
        }

        public Builder WithHairType(string hairType)
        {
            this.HairType = hairType;
            return this;
        }

        public Builder WithHairColor(string hairColor)
        {
            this.HairColor = hairColor;
            return this;
        }
        public People Build()
        {
            return new People(this);
        }
    }

        static void Main(string[] args)
        {
            People people1 = new Builder("厨师", "张三")
                .WithHairColor("黑")
                .WithHairType("波浪卷发")
                .Build();
            Console.WriteLine(people1.Show());

            People people2 = new Builder("程序员", "李四")
                .WithHairColor("白")
                .Build();
            Console.WriteLine(people2.Show());
            Console.ReadLine();
        }