C# JSON 反序列化异常

Question

如果我尝试使用从 List 或 Dictionary 派生的根类来反序列化一系列类，我会收到以下异常：

"值 \"System.Collections.Generic.Dictionary`2[System.String,System.Object]\" 不是 \"JSONTesting.UserInformation\" 类型，不能用于 这个通用集合。\r\n参数名称：值"

这是我用来创建 JSON 文件并对其进行反序列化的代码。这只是一个演示问题的小示例项目：

    private void BuildUserInfo(object sender, EventArgs e)
    {
      Users users = new Users();
      UserInformation userInformation;

      //Item 1
      userInformation = new UserInformation();
      userInformation.Name = "John Doe";
      userInformation.Age = "50";
      userInformation.Addresses.Add(new Address("11234 Smith Pl.", "Orlando", "FL", "32789"));
      userInformation.Addresses.Add(new Address("553 Park St.", "Boston", "MA", "02115"));
      userInformation.PhoneNumbers.Add(new PhoneNumber("617", "111-2222", string.Empty));
      userInformation.PhoneNumbers.Add(new PhoneNumber("508", "236-0173", "22734"));
      users.Add(userInformation);

      //Serialize
      JavaScriptSerializer serializer = new JavaScriptSerializer();
      StreamWriter streamOut = null;
      string outString = string.Empty;

      outString = serializer.Serialize(users);
      streamOut = new StreamWriter("OUTFILE.JSON");
      streamOut.Write(outString);

      streamOut.Close();
    }

    private void ReadUserInfo(object sender, EventArgs e)
    {
      JavaScriptSerializer serializer;
      StreamReader streamIn = null;
      Users retrievedUsers = null;

      if (File.Exists("OUTFILE.JSON"))
      {
        streamIn = new StreamReader("OUTFILE.JSON");
        serializer = new JavaScriptSerializer();
        retrievedUsers = serializer.Deserialize<Users>(streamIn.ReadToEnd());

        streamIn.Close();
      }
    }
  }

  public class Users: List<UserInformation>
  {
    public UserInformation getUserByName(string name)
    {
      foreach (UserInformation user in this)
      {
        if (name == user.Name)
          return user;
      }

      return null;
    }
  }

  public class UserInformation
  {
    public string Name;
    public string Age;

    public List<Address> Addresses;
    public List<PhoneNumber> PhoneNumbers;

    public UserInformation()
    {
      Name = string.Empty;
      Age = string.Empty;
      Addresses = new List<Address>();
      PhoneNumbers = new List<PhoneNumber>();
    }

    public UserInformation(string Name, string Age)
    {
      this.Name = Name;
      this.Age = Age;
      Addresses = new List<Address>();
      PhoneNumbers = new List<PhoneNumber>();
    }
  }

  public class Address
  {
    public string Street;
    public string City;
    public string State;
    public string PostalCode;

    public Address()
    {
      Street = string.Empty;
      City = string.Empty;
      State = string.Empty;
      PostalCode = string.Empty;
    }

    public Address(string Street, string City, string State, string PostalCode)
    {
      this.Street = Street;
      this.City = City;
      this.State = State;
      this.PostalCode = PostalCode;
    }
  }

  public class PhoneNumber
  {
    public string AreaCode;
    public string Number;
    public string Extension;

    public PhoneNumber()
    {
      AreaCode = string.Empty;
      Number = string.Empty;
      Extension = string.Empty;
    }

    public PhoneNumber(string AreaCode, string Number, string Extension)
    {
      this.AreaCode = AreaCode;
      this.Number = Number;
      this.Extension = Extension;
    }
  }

这是由 BuildUserInfo 函数生成的 JSON：

    [
      {
        "Name": "John Doe",
        "Age": "50",
        "Addresses": [
          {
            "Street": "11234 Smith Pl.",
            "City": "Orlando",
            "State": "FL",
            "PostalCode": "32789"
          },
          {
            "Street": "553 Park St.",
            "City": "Boston",
            "State": "MA",
            "PostalCode": "02115"
          }
        ],
        "PhoneNumbers": [
          {
            "AreaCode": "617",
            "Number": "111-2222",
            "Extension": ""
          },
          {
            "AreaCode": "508",
            "Number": "236-0173",
            "Extension": "22734"
          }
        ]
      }
    ]

如果我更改 Users 类，使其不是从 List 派生的，而只是将其设为具有内部 List 集合的类，它就可以正常工作。一个例子：

public class Users
{
  public List<UserInformation> UserItems = new List<UserInformation>();
}

我需要更改哪些内容才能反序列化此 JSON？

编辑：尝试下面评论中的链接，我更改为以下内容：

public class Users(IEnumerable<UserInformation> collection) : base (collection) {

}

我收到构建错误：

错误 1 ​​类、结构或接口成员中的无效标记 '(' 声明 c:\Local .NET 项目\2010\JSONTesting1\Form1.cs 66 25 JSONTesting1 错误 2 { 预期 c:\Local .NET 项目\2010\JSONTesting1\Form1.cs 66 25 JSONTesting1 错误 3； 预期 c:\Local .NET Projects\2010\JSONTesting1\Form1.cs 66 69 JSONTesting1 错误 4 无效 类、结构或接口成员声明 c:\Local 中的标记 ')' .NET 项目\2010\JSONTesting1\Form1.cs 66 93 JSONTesting1 错误 5 } 预期 c:\Local .NET 项目\2010\JSONTesting1\Form1.cs 153 2 JSONTesting1

Answer 1

你有使用JavaScriptSerializer吗？如果你这样做了，我们肯定缺少一些配置细节，但是Newtonsoft.Json 处理这种情况而无需任何调整：

private static void BuildUserInfo()
{
    // ...

    //Serialize
    File.WriteAllText("OUTFILE.JSON", Newtonsoft.Json.JsonConvert.SerializeObject(users));
}

private static void ReadUserInfo()
{
    Users retrievedUsers = null;

    if (File.Exists("OUTFILE.JSON"))
    {
        var json = File.ReadAllText("OUTFILE.JSON");

        retrievedUsers = Newtonsoft.Json.JsonConvert.DeserializeObject<Users>(json);
    }
}