如何找到登录到.Net核心的当前用户id

using Microsoft.AspNetCore.Http;
using System.Security.Claims;

public class MyController : Controller
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    public MyController(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    public IActionResult MyAction()
    {
        HttpContext context = _httpContextAccessor.HttpContext;
        ClaimsPrincipal user = context.User;

        // 查找名为"UserId"的声明
        Claim userIdClaim = user.FindFirst("UserId");

        if (userIdClaim != null)
        {
            string userId = userIdClaim.Value;
            // 使用userId进行后续操作
        }
        else
        {
            // 未找到"UserId"声明
        }

        // 其他操作...

        return View();
    }
}