Wsrtjtyk

In my Controller I execute another Void Function after the date saved to DB. But sometimes it's show this error :

A second operation started on this context before a previous
asynchronous operation completed. Use 'await' to ensure that any
asynchronous operations have completed before calling another method
on this context. Any instance members are not guaranteed to be thread
safe.

...and here is a sample of my controller :

public ActionResult All(Chapter chapter){



    var x = db.Post.Where(p => p.PostID == chapter.PostID).FirstOrDefault();

    if (x == null){return View(chapter);}



    counter++;



    db.Chapter.Add(chapter);

    db.SaveChangesAsync();                      



    savepost(chapter.PostID, counter);



    return RedirectToAction("Index");

}

and here is the Void method:

public void savepost(int id,int counter)

{

    var article = db.Post.Find(id);

    article.LastUpdate = DateTime.Now;

    article.ChapterCount = counter;



    db.Entry(article).State = EntityState.Modified;

    db.SaveChanges();

}

How i can solve this ?

Shortest fix:

//db.SaveChangesAsync(); 

db.SaveChanges(); 

the slightly better option:

public async Task<ActionResult> All(Chapter chapter)

{

   ....

   await db.SaveChangesAsync(); 

   ...

}

You are not awaiting the call to SaveChangesAsync(), meaning it will (can) be forked off on a separate thread. And then giving you this error.

As an exercise, you can make a similar change to the SavePost() method:

• make it an async Task method


• replace SaveChanges() with await db.SaveChangesAsync()


• await the call to SavePost()