无法使用DataContractJsonSerializer将对象序列化为JSON

Question

I have taken the following code from https://msdn.microsoft.com/en-us/library/bb410770(v=vs.110).aspx and put it in a Visual Studio project.

Program.cs

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;

namespace DataContractJsonSerializer_Example
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a person object.
            Person p = new Person();
            p.name = "John";
            p.age = 42;

            // Serialize the Person object to a memory stream using DataContractJsonSerializer.
            MemoryStream stream1 = new MemoryStream();
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(DataContractJsonSerializer));

            // Use the WriteObject method to write JSON data to the stream.
            ser.WriteObject(stream1, p);

            // Show the JSON output.
            stream1.Position = 0;
            StreamReader sr = new StreamReader(stream1);
            Console.Write("JSON form of Person object: ");
            Console.WriteLine(sr.ReadToEnd());
            Console.Read();
        }
    }
}

Person.cs

using System.Runtime.Serialization;

namespace DataContractJsonSerializer_Example
{
    [DataContract]
    class Person
    {
        [DataMember]
        internal string name;

        [DataMember]
        internal int age;
    }
}

I receive the following runtime error:

An unhandled exception of type 'System.Runtime.Serialization.InvalidDataContractException' occurred in System.Runtime.Serialization.dll

Additional information: Type 'System.Runtime.Serialization.Json.DataContractJsonSerializer' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute.  If the type is a collection, consider marking it with the CollectionDataContractAttribute.

The exception occurs at this line:

ser.WriteObject(stream1, p);

That seems odd. Rather than marking the Person class, it seems to want me to mark the DataContractJsonSerializer class itself. Another odd thing is that I downloaded the sample code from MSDN and ran their version, which is basically the same as mine, without any trouble. Theirs is a VS2010 project, and they have the Person class in the same file as the class containing the Main method, but that shouldn't be making a difference. Can anyone tell me what I'm doing wrong?

Answer 1

The issue is on line DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(DataContractJsonSerializer)); it should be DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Person));