Question

我正在开发.net核心Web应用程序，并且遇到了一个问题，即我的Usermanager被处置，导致错误。

public async void DeleteInactiveUserData()
{
    var dayAgo = DateTimeOffset.UtcNow.AddDays(-1);
    var inactiveGuests = _userManager.Users.Where(u => u.Guest && u.LastLoginDate < dayAgo);
    var yearAgo = DateTimeOffset.UtcNow.AddYears(-1);
    var inactiveUsers = _userManager.Users.Where(u => !u.Guest && u.LastLoginDate < yearAgo);
    var toBeDeletedUsers = inactiveGuests.Concat(inactiveUsers).ToList();
    for (int i = toBeDeletedUsers.Count() - 1; i >= 0; i--)
    {
        var user = toBeDeletedUsers[i];
        _logger.LogInformation("Deleting user " + user.UserName + " for inactivity.");
        await _userManager.DeleteAsync(user); // Usermanager is disposed here
    }
}

如何在使用等待时停止处理服务？

Answer 1

正如评论所建议的那样，我没有提供足够的细节，但在扩展问题时遇到了答案。我学到的是这样：

始终返回异步任务，而不是异步void

Cannot access a disposed object. A common cause of this error is disposing a context

在关闭范围之前等待任务：

using (var scope = _serviceScopeFactory.CreateScope())
        {
            var accountServive = scope.ServiceProvider.GetService<IAccountService>();
            await accountServive.DeleteInactiveUserData();
        }

如果不等待任务，该功能将继续，作用域将关闭并且您的服务将被处置。要了解异步并等待，请转到此处：

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/async/

.Net核心-停止处理服务/用户管理器/使服务保持活动状态

1 个答案: