对PageModel的POST请求将创建新实例，从而删除模型的先前值

Question

Index.cshtml

@page
@model IndexModel
@Html.AntiForgeryToken()
@{
  ViewData["Title"] = "Home page";
 }

 <div class="text-center">
   <div class="board">
     @for (var y = 0; y < Model._height; y++)
       {
         <div class="line">
            @for (var x = 0; x < Model._width; x++)
            {
                <div class="column"
                     onclick="openTile(@y, @x)"
                     oncontextmenu="putFlag(@y, @x); return false;">
                    <p class="value">@Model.GameObj._userfield.UserField[y][x]</p>
                </div>
            }
         </div>
       }
   </div>
 </div>

<script type="text/javascript">
function openTile(y, x) {
    $.ajax({
        url: '/Index?handler=OpenTile',
        type: "POST",
        data: {
            y: y,
            x: x
        },
         headers: {
               RequestVerificationToken: 
                   $('input:hidden[name="__RequestVerificationToken"]').val()
        }
    });
    console.log(`Tile (${y},${x}) was clicked.`);
}
function putFlag(y, x) {
    console.log(`Tile (${y},${x}) was right clicked.`);
}

Index.cshtml.cs

namespace MineSweeperWebApp.Pages
{
  public class IndexModel : PageModel
  {
    private readonly ILogger<IndexModel> _logger;
    public readonly int _width = 10;
    public readonly int _height = 10;
    private readonly int _mineCount = 10;

    public GameController GameObj;

    public IndexModel(ILogger<IndexModel> logger)
    {
        _logger = logger;
    }

    public void OnGet()
    {
        GameObj = new GameController(_height, _width, _mineCount);
    }
    public void OnPostOpenTile(int y, int x)
    { 
        if (GameObj._isFirstMove) GameObj.MakeFirstMove(y, x);
        else GameObj.ValidateUserInput(y, x);
    }
  }
}

创建页面后，我将创建一个gameObj实例，该实例基本上就是所有游戏逻辑发生的地方。 单击板上的一个磁贴后，我正在对PageModel进行AJAX调用，问题是正在创建一个新的PageModel实例，而我的GameObj却是一个NULL值。 我有什么办法可以继续使用在第一个GET请求期间创建的gameObj。