小编Lew*_*wis的帖子

当我第二次执行我的HttpPost表单时,我一直收到以下错误.

InvalidOperationException: A second operation started on this context before a previous operation completed. 

Any instance members are not guaranteed to be thread safe.

我的ApplicationDbContext在我的控制器中初始化为:

public class AssetController : Controller
{
    private readonly ApplicationDbContext _context;

    public AssetController(
        ApplicationDbContext context,)
    {
        _context = context;
    }

这是控制器中处理帖子并保存的功能:

[HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Add(IFormFile file, AddAssetViewModel model)
    {
        if (ModelState.IsValid)
        {
            var currentUser = await _userManager.GetUserAsync(HttpContext.User);

            var assetOwnership =
                _context.AssetOwnership.SingleOrDefault(o => o.AssetOwnershipId == model.OwnershipId);

            var origin = _context.Location.SingleOrDefault(l => l.LocationId == model.OriginId);

            var …