具有逻辑的 C# 私有(private) Setter

Question

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

namespace Crystal_Message
{
    class Person
    {
        private string firstName="";
        private string lastName= "";
        private string phone="";


        public Person(string firstName, string lastName, string phone)
        {
            this.FirstName = firstName;
            this.LastName = lastName;
            this.PhoneNumber = phone;


        }

        public string FirstName
        {
            get { return firstName; }

            set
            {
                if (string.IsNullOrWhiteSpace(this.firstName)){

                    throw new ArgumentNullException("Must Include First Name");
                }

                this.firstName = value;
            }

        }

        public string LastName
        {
            get { return lastName; }

            set
            {
                if (string.IsNullOrWhiteSpace(lastName)){

                    throw new ArgumentNullException("Must Include Last Name");
                }

                this.lastName = value;
            }

        }

        public string PhoneNumber
        {
            get { return phone; }

            set
            {
                if (string.IsNullOrWhiteSpace(phone)){

                    throw new ArgumentNullException("Must Include Phone Number");
                }

                this.phone = value;
            }

        }


        public override string ToString()
        {
            return "First Name: " + this.FirstName + " " + " Last Name: " + this.LastName + " Phone Number: " + this.PhoneNumber;
        }


    }
}

我有一个简单的 person 类，它包含名字、姓氏和电子邮件。它对我有用，它不会被子分类。我正在构建一个小型应用程序，person 类很合适。

我唯一的问题是，如何使用内部逻辑实现一个private setter，以确保该值不为空或不为空？

Answer 1

仅将 setter 设为私有(private)。另外，你有一个问题:

string.IsNullOrWhiteSpace(lastName)

将读取现有 属性值。您应该改为检查新提供的 value:

string.IsNullOrWhiteSpace(value)

最终代码:

    public string LastName
    {
        get { return lastName; }

        private set
        {
            if (string.IsNullOrWhiteSpace(value)) {
                throw new ArgumentNullException("Must Include Last Name");
            }

            lastName = value;
        }
    }