如何修复此错误：'IFeatureCollection 已被处置。在 Asp.net Core Mvc 中

Question

如何修复此错误：'IFeatureCollection 已被释放。在 Asp.net Core Mvc 中

我使用 Filesystem Watcher 来获取 Path 中文件的事件数据 一切正常，我在数据库中发送了跟踪信息，但是当我尝试在 OnChanged 方法中使用它们时，它们是会话值的 Adminid 和 roleid 导致了这个问题

这是我的控制器：

 **public IActionResult RHManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            var Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());



            FileSystemWatcher watcher = new FileSystemWatcher();

            //Mention the Path that you want to monitor file events.

            watcher.Path = @"\\100.100.1.6\drh-m$";
            watcher.IncludeSubdirectories = true;
            watcher.NotifyFilter = NotifyFilters.Attributes |
            NotifyFilters.CreationTime |
            NotifyFilters.DirectoryName |
            NotifyFilters.FileName |
            NotifyFilters.LastAccess |
            NotifyFilters.LastWrite |
            NotifyFilters.Security |
            NotifyFilters.Size;
            watcher.Filter = "*.*";
            //File System Events to listen them
            watcher.Changed += new FileSystemEventHandler(OnChanged);
            watcher.Created += new FileSystemEventHandler(OnChanged);
            watcher.Deleted += new FileSystemEventHandler(OnChanged);

            // Starting monitoring the folder.
            watcher.EnableRaisingEvents = true;

            return View(watcher);
        }


       

         void OnChanged(object source, FileSystemEventArgs e)
        {
            TraceFileManager trace = new TraceFileManager();
            trace.Time = DateTime.Now;
            trace.Adminid = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            trace.Roleid = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            trace.Changedfile = e.Name;
            trace.Seen = false;
            trace.Etat = "En attente";
            trace.Changetype = e.ChangeType.ToString();
            _context.Add(trace);
            
            _context.SaveChangesAsync();
        }**

Answer 1

作用域服务在请求结束时被释放。 主要问题是OnChanged 可以在请求结束后调用。 当您需要请求之外的作用域服务时，您需要注入IServiceScopeFactory 并使用它来获取服务。

同上，当 OnChanged 中调用属性 ControllerBase.HttpContext 时。 但是，不可能在请求之外获取 HttpContext。 然后，您需要在请求中从 HttpContext 获取信息并在OnChanged 调用中设置。

public RhController : ControllerBase
{
    private IServiceScopeFactory _serviceScopeFactory;

    public RhController(IServiceScopeFactory serviceScopeFactory)
    {
        _serviceScopeFactory = serviceScopeFactory;
    }

    public IActionResult RHManager()
    {
        ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
        ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
        var Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
        var IdRole = int.Parse(HttpContext.Session.GetInt32("id").ToString());


        FileSystemWatcher watcher = new FileSystemWatcher();
        ...
        //File System Events to listen them
        var fileSystemEventHandler = new FileSystemEventHandler((o, e) => OnChanged(e, Idadmin, IdRole));
        watcher.Changed += fileSystemEventHandler;
        watcher.Created += fileSystemEventHandler;
        watcher.Deleted += fileSystemEventHandler;

        // Starting monitoring the folder.
        watcher.EnableRaisingEvents = true;

        return View(watcher);
    }

    void OnChanged(FileSystemEventArgs e, int admin, int role)
    {
        using (var scope = serviceScopeFactory.CreateScope())
        {
            var context = scope.ServiceProvider.GetService<RhContext>();

            TraceFileManager trace = new TraceFileManager();
            trace.Adminid = admin;
            trace.Roleid = role;
            ...

            context.Add(trace);
            context.SaveChangesAsync();
        }
    }
}

Answer 2

我尝试了您的解决方案，但问题仍然存在

完整的控制器代码如下：

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.DependencyInjection;
using RoleBasedAuthorization.Models;
using System;
using System.Diagnostics;
using System.IO;
using System.Threading.Tasks;

namespace RoleBasedAuthorization.Controllers
{
    public class FileManagerController : Controller
    {

        ENAPORTALContext _context = new ENAPORTALContext();
        private readonly IServiceScopeFactory _serviceScopeFactory;

        public FileManagerController(IServiceScopeFactory serviceScopeFactory)
        {
            _serviceScopeFactory = serviceScopeFactory;
        }
        public IActionResult PQManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            return View();
        }
        public IActionResult FormulairesFManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            return View();
        }
        public IActionResult DGManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            return View();
        }
        public IActionResult DAFManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DAPManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DPCManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DMVManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult PublicManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            return View();
        }
        public IActionResult DTManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DTPManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DTTManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult SMQManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult BoiteIdees()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());

            return View();
        }

      


        public IActionResult Documentation()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        public IActionResult DFManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            return View();
        }
        /*     FILE MANAGER DRH*/


























        public IActionResult RHManager()
        {
            ViewBag.Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());
            ViewBag.RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString());
            var Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());



            FileSystemWatcher watcher = new FileSystemWatcher();

            //Mention the Path that you want to monitor file events.

            watcher.Path = @"\\100.100.1.6\drh-m$";
            watcher.IncludeSubdirectories = true;
            watcher.NotifyFilter = NotifyFilters.Attributes |
            NotifyFilters.CreationTime |
            NotifyFilters.DirectoryName |
            NotifyFilters.FileName |
            NotifyFilters.LastAccess |
            NotifyFilters.LastWrite |
            NotifyFilters.Security |
            NotifyFilters.Size;
            watcher.Filter = "*.*";
            //File System Events to listen them
            watcher.Changed += new FileSystemEventHandler(OnChanged);
            watcher.Created += new FileSystemEventHandler(OnChanged);
            watcher.Deleted += new FileSystemEventHandler(OnChanged);

            // Starting monitoring the folder.
            watcher.EnableRaisingEvents = true;

            return View(watcher);
        }


       

         void OnChanged(object source, FileSystemEventArgs e)
        {
            using (var scope = _serviceScopeFactory.CreateScope())
            {
                var context = scope.ServiceProvider.GetService<ENAPORTALContext>();
                var Idadmin = int.Parse(HttpContext.Session.GetInt32("id").ToString());     /*Admin ID variable session will be inserted into db               error : IFeatureCollection has been disposed.*/
                var RoleCreateur = int.Parse(HttpContext.Session.GetInt32("role_id").ToString()); /*role ID variable session will be inserted into db*/
                TraceFileManager trace = new TraceFileManager();
                trace.Time = DateTime.Now;
                trace.Adminid = Idadmin;
                trace.Roleid = RoleCreateur;
                trace.Changedfile = e.Name;
                trace.Seen = false;
                trace.Etat = "En attente";
                trace.Changetype = e.ChangeType.ToString();
                _context.Add(trace);

                _context.SaveChangesAsync();
            }
        }


    










    }
}