MVC音樂商店

Question

我試圖做MVC musicstore教程和使用編輯時，部分6後，我得到這個錯誤：

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.OptimisticConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

知道爲什麼這是什麼原因？

[HttpPost] 
public ActionResult Edit(Album album) 
{ 
    if (ModelState.IsValid) 
    { 
     db.Entry(album).State = EntityState.Modified; 
     db.SaveChanges(); 
     return RedirectToAction("Index"); 
    } 
    ViewBag.GenreId = new SelectList(db.Genres, "GenreId", "Name", album.GenreId); 
    ViewBag.ArtistId = new SelectList(db.Artists, "ArtistId", "Name", album.ArtistId); 

    return View(album); 
} 

有人腳手架

Answer 1

確保你打電話SaveChanges任何插入，更新或刪除在兩者之間。