DbContext is mark as disposed when It's not

Question

My project got a Exception :

System.ObjectDisposedException: Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose() on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.

I searched for the answer but all I got is use AddScoped or AddTransient instead of AddSingleton. But in my code, It's AddScoped already. Then, I tracking the creation and dispose by adding this code to constructor and Dispose method.

Constructor:

crrGuid = Guid.NewGuid(); //this is a field I added to tracking
Console.WriteLine("Created: " + crrGuid.ToString());

Dispose Method:

public void Dispose()
{
    Dispose(true);
    GC.SuppressFinalize(this);
    Console.WriteLine("Disponsing :" + crrGuid.ToString());
}

And this is the console I got after perform 2 request. The first, It's works, I can fetch my data. But the second request is not, It thrown exception even my Dispose method is not called yet (see the last line of console screenshot):

I got this exception only with some Entity/Table, others work fine.

PS: My code is too much, I don't know what should be share. Please comment, If I could public it, I will edit my post

Edit 1: Add constructor and Dispose method actually in my DBContext

public Context([NotNull]DbContextOptions options) : base(options)
{
    Guid = Guid.NewGuid();
    Console.ForegroundColor = ConsoleColor.Cyan;
    Console.WriteLine("Create DbContext:" + Guid);
    Console.ResetColor();
}

public override void Dispose()
{
    base.Dispose();
    Console.WriteLine("Dispose DbContext:" + Guid);
}

Proposed duplicate

I have read the proposed duplicate and I think my case is different because I found the cause. The cause is in my conversion in my DBContext. The answer in linked topic definitely not helped me anything in solving this.

Any object created by DI will automatically have its `Dispose` called by the DI when it's finished with. Are your calling `Dispose` for yourself as well? — Jasper Kent, Apr 28 '20 at 10:08
Can you share the code where you're actually using the `DbContext`? — canton7, Apr 28 '20 at 10:08
@canton7 what's part of code you want to see? Constructor? or Dispose method? Push a file with more than 200 code line is not a good Idea — Hoàng Minh Thông, Apr 28 '20 at 10:11
@HoàngMinhThông Create a [mcve] then (see [ask]) -- that will reduce it below 200 lines — canton7, Apr 28 '20 at 10:12
Override `DisposeAsync` method as well and see if it is called. — Ivan Stoev, Apr 28 '20 at 11:03
@IvanStoev I overrided `DisposeAsync` but the exception was thrown before my DbContext disposed. See at: https://i.imgur.com/B6aIimo.png — Hoàng Minh Thông, Apr 28 '20 at 11:08
How are you registering your dbContext? With `AddDbContext` or `AddDbContextPool`? See, if EFC says the context is disposed, be sure it is, the question is first how and when (which code) and finally why. — Ivan Stoev, Apr 28 '20 at 11:26
@IvanStoev I used `AddDbContext`. Idk why it cause exception on my computer. My code work properly on my colleague's computer. — Hoàng Minh Thông, Apr 28 '20 at 13:45

score 1 · Accepted Answer · answered May 04 '20 at 02:08

I found the cause. Because of my conversion select form it table like this:

modelBuilder.Entity<MyEntity>().Property(x => x.Childs).HasConversion(
  x => x.Select(y => y.Id).StringJoin(","),
  x => MyEntities.Where(myentity => x.Split(',', StringSplitOptions.RemoveEmptyEntries)
                                    .Select(z => int.Parse(z)).Contains(myentity.Id)).ToList());

DbContext is mark as disposed when It's not

Proposed duplicate

1 Answers1