我有关于ViewModel的序列化和反序列化的问题-我创建了ViewModel的示例并将其分配给视图的DataContext。我有一个包含ViewModel中对象的列表，我需要对其进行序列化和反序列化。
在反序列化时，列表的大小一直在增长，不确定这里发生了什么。ViewModel不就是类的另一个示例吗？
例如，我从一个类的2个对象开始，我序列化并反序列化它，最后得到4条记录，记录的大小不断增加。
我为此做了一个测试场景，我使用的是JSON序列化器。
//---查看模型---//

using System;
using System.Windows;
using System.Windows.Input;
using Newtonsoft.Json;

namespace JsonTest
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        CarVM = new CarViewModel(); //Create instance if View Model and assign it to the datacontext
        this.DataContext = CarVM;

    }

    private CarViewModel CarVM { get; set; }

    /// <summary>
    /// Serialize
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void Serialize_Click(object sender, RoutedEventArgs e)
    {
        //Serialize and write to file
        using (var fileStream = new FileStream(@"Config123.cfg", FileMode.Create))
        using (var streamWriter = new StreamWriter(fileStream))
        using (var jsonWriter = new JsonTextWriter(streamWriter))
        {
            JsonSerializer ser = new JsonSerializer();
            ser.Formatting = Newtonsoft.Json.Formatting.Indented; //Format the output
            ser.TypeNameHandling = TypeNameHandling.Auto;
            ser.Serialize(jsonWriter, CarVM); //Serailizing View Model objects
            jsonWriter.Flush();
        }

        printData();
    }

    /// <summary>
    /// Deserialize
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void Deserialize_Click(object sender, RoutedEventArgs e)
    {
        using (var fileStream = new FileStream(@"Config123.cfg", FileMode.Open))
        using (var streamReader = new StreamReader(fileStream))
        using (var jsonReader = new JsonTextReader(streamReader))
        {
            JsonSerializer ser = new JsonSerializer();
            ser.Formatting = Newtonsoft.Json.Formatting.Indented;
            ser.TypeNameHandling = TypeNameHandling.Auto;
            CarVM = ser.Deserialize<CarViewModel>(jsonReader); //reload the ViewModel with new viewmodel obtained from serializing
        }
        Console.WriteLine("--Deserialization--");
        printData();
   }

    /// <summary>
    /// Print Data 
    /// </summary>
    private void printData()
    {
        foreach(Car c in CarVM.Cars)
        {
            Console.WriteLine(c.make + " " + c.year);
        }
    }
    }
 }

//---简单类---//

namespace JsonTest
{
class Car
{
    public string make { get; set; }
    public int year { get; set; }

    public Car() { }

    public Car(string make, int year)
    {
        this.make = make;
        this.year = year;
    }
  }
}

//---查看----//

<Window x:Class="JsonTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:JsonTest"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Button Content="Serialize" Margin="50" BorderThickness="0" Click="Serialize_Click"/>
        <Button Grid.Column="1" Content="Deserialize" Margin="50" BorderThickness="0" Click="Deserialize_Click"/>
    </Grid>
</Window>

//---输出---//

--Serialization--
DeLorean 1975
Subaru 2018
--Deserialization--
DeLorean 1975
Subaru 2018
DeLorean 1975
Subaru 2018
--Serialization--
DeLorean 1975
Subaru 2018
DeLorean 1975
Subaru 2018
--Deserialization--
DeLorean 1975
Subaru 2018
DeLorean 1975
Subaru 2018
DeLorean 1975
Subaru 2018

//---汽车视图模型---//

class CarViewModel
    {
        public CarViewModel()
        {
            Cars = new List<Car>();
            Cars.Add(new Car("DeLorean", 1975));
            Cars.Add(new Car("Subaru", 2018));
        }

        private  List<Car> cars; 
        public List<Car> Cars
        {
            get { return cars; }
            set { cars = value; }
        }
    }