Question

我试图从2个类使用JSON.Net生成一些JSON。以下是JSON的示例

{
  "UserToken" : "string",
  "MyProject" : 
  {
    "MyProjectId" : "string",
    "ProjectId" : "string",
    "ContactId" : "string",
    "DisplayOrder" : "int"
  }
}

这里是C＃Classes

public class MyProject
{
    public string MyProjectId { get; set; }
    public string ProjectId { get; set; }
    public string ContactId { get; set; }
    public int DisplayOrder { get; set; }
}

public class RootObject
{
    public string UserToken { get; set; }
    public MyProject MyProject { get; set; }
}

你可以看到＆＃34; RootObject＆＃34;包含一个＆＃34; MyProject＆＃34;对象，但我无法解决如何实例化这个，所以我可以传递像：

这样的值

RootObject o = new RootObject();
o.MyProject.MyProjectId = "something";

我试过通过论坛搜索，但我得到的所有请求都是列表 - 我可以用它来解决问题，但我认为我的理解存在差距！

提前致谢， Ĵ

Answer 1

将RootObject定义更改为

public class RootObject
{
     public RootObject() {
          this.MyProject = new MyProject();
     }
     public string UserToken { get; set; }
     public MyProject MyProject { get; set; }
}

或更改代码

RootObject o = new RootObject();
o.MyProject.MyProjectId = "something";

到

RootObject o = new RootObject();
o.MyProject = new MyProject();
o.MyProject.MyProjectId = "something";

代码的问题在于o.MyProject没有实例化。

Answer 2

您正在创建父对象，但您还需要创建子对象，否则您将获得空引用异常。

RootObject o = new RootObject();
o.MyProject = new MyProject();   // <<<THIS
o.MyProject.MyProjectId = "something";

或者您可以像这样使用object initializer：

RootObject o = new RootObject
{
    MyProject = new MyProject
    {
        MyProjectId = "something",
    }
};

Answer 3

创建MyProject的对象，并将其分配给public MyProject类的RootObject()。

RootObject o = new RootObject();
MyProject mp = new MyProject();
mp.MyProjectId = "something";
o.MyProject = mp;

Answer 4

按如下方式更改您的代码。

public class MyProject
    {
        public MyProject()
        {
          this.MyProjectId =string.Empty;
          this.ProjectId =string.Empty;
          this.ContactId =string.Empty;
        }

        public string MyProjectId { get; set; }
        public string ProjectId { get; set; }
        public string ContactId { get; set; }
        public int DisplayOrder { get; set; }
    }

    public class RootObject
    {

        public RootObject()
        {
          this.MyProject =new MyProject ();
        }

        public string UserToken { get; set; }
        public MyProject MyProject { get; set; }
    }

从父类实例化子对象

4 个答案: