Unity -将新变量添加到二进制格式的保存数据？

[System.Serializable]
public class MyData
{
    public int myVariable;
    [SerializeField]
    private string myPrivateVariable;
}

using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

...

MyData data = new MyData();
data.myVariable = 10;
data.myPrivateVariable = "Hello";

BinaryFormatter formatter = new BinaryFormatter();
FileStream fileStream = File.Create("data.dat");
formatter.Serialize(fileStream, data);
fileStream.Close();

using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

...

BinaryFormatter formatter = new BinaryFormatter();
FileStream fileStream = File.Open("data.dat", FileMode.Open);
MyData data = (MyData)formatter.Deserialize(fileStream);
fileStream.Close();

// 使用data中的变量进行后续操作
int variable = data.myVariable;
string privateVariable = data.myPrivateVariable;