Question

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

namespace Creational.Builder
{
    public class Person
    {
        public string Name;

        public string Position;

        public class Builder : PersonInfoBuilder<Builder>
        {

        }

        public static Builder New => new Builder();

        public override string ToString()
        {
            return $"{nameof(Name)}: {Name}, {nameof(Position)}: {Position}";
        }
    }

    public abstract class PersonBuilder
    {
        protected Person person = new Person();

        public Person Build()
        {
            return person;
        }
    }

    // class Foo : Bar<Foo>
    public class PersonInfoBuilder<SELF> : PersonBuilder
      where SELF : PersonInfoBuilder<SELF>
    {
        public SELF Called(string name)
        {
            person.Name = name;
            return (SELF)this;
        }
    }

    public class PersonJobBuilder<SELF> : PersonInfoBuilder<PersonJobBuilder<SELF>>
      where SELF : PersonJobBuilder<SELF>
    {
        public SELF WorksAsA(string position)
        {
            person.Position = position;
            return (SELF)this;
        }
    }

    internal class Program
    {
        public static void Main(string[] args)
        {
            var me = Person.New
                .Called("Harry")
                .WorksAsA("Testing")
                .Build();
            Console.WriteLine(me);

            var builder = new Builder();
            var person = builder.WorksAsA("d").
            Console.WriteLine(person);
        }
    }
}

来自Designpatterns课程的代码，但是它并不完美。我收到以下错误：

Person.Builder'不包含'WorksAsA'的定义，也找不到扩展方法'WorksAsA'接受类型为'Person.Builder'的第一个参数（您是否缺少using指令或程序集引用？）

Builder'是一个命名空间，但其使用方式类似于Creational.Builder

在声明局部变量“ person”之前不能使用

如何解决这些问题？

Answer 1

公共类Builder：PersonInfoBuilder {

}

必须是：

公共类生成器：PersonJobBuilder {

}

解决了WorksAsa，但没有解决其他问题。

递归泛型的Fluence Builder继承

1 个答案: