创建构造函数并发送给视图

本文关键字：视图 并发 构造函数 创建 | 更新日期: 2023-09-27 18:08:09

我正在为我的狗创建一个谱系树，但我遇到了一些麻烦。我有三个类:

犬组:

 public class Dog
    {
        public string Name { get; set; }
        public string Merit1 { get; set; }
        public string Merit2 { get; set; }           
    }

系谱类:

 public class Pedigree
    {
        public Dog Father { get; set; }
        public Dog GrandFather { get; set; }
        public Dog GrandMother { get; set; }
        public Dog GrandFathersFather { get; set; }
        etc....

我想发送给视图的类，这里有硬编码的值，只是为了让我开始:

public class DogContentPage : ContentPage
    {
        public DogContentPage()
        {
            Name = "The Dog";
            Age = "4";

            Pedigree = new Pedigree();
            {
                mother = new Dog {Name = "Chanelle", Merit1 = "Universal"};
                father = new Dog {Name = "dfdfdf", Merit1 = "dfdfdfdfdf"};
            };
        }
        public string Name { get; set; }
        public string Age { get; set; }
        public Dog mother { get; set; }
        public Dog father { get; set; }  
    }

在视图中，我尝试这样做:

    @model EmmysBlog_Core.Models.Dog.DogContentPage
@{
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<h1>@Model.Name</h1>
<p>@Model.Pedigree.Mother.Name</p>
<p>@Model.Pedigree.Mother.Merit1</p>

我得到的错误是，对象没有设置为实例…我想要的是能够显示我的狗的属性…我错过了什么?

创建构造函数并发送给视图

在Pedigree构造函数中，您还需要实例化属性类，它们没有实例化，因此会抛出null引用异常:

public Pedigree()
{
    this.Mother = new Dog{Name = "Chanelle", Merit1 = "Universal"};
    this.Father = new Dog{Name = "dfdfdf", Merit1 = "dfdfdfdfdf"};
    this.GrandFather = new Dog();
    this.GrandMother = new Dog();
    this.GrandFathersFather = new Dog();
}

在你的代码中也有错误，在你的方式中应该是这样的:

Pedigree obj = new Pedigree
{
    Mother = new Dog {Name = "Chanelle", Merit1 = "Universal"};
    Father = new Dog {Name = "dfdfdf", Merit1 = "dfdfdfdfdf"};
};
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