無法修復'對象無法刪除，因爲它在ObjectStateManager中找不到。'

Question

我嘗試從使用LINQ的數據中刪除對象時出現以下錯誤。

The object cannot be deleted because it was not found in the ObjectStateManager. 

注意：當我嘗試直接從數據庫運行查詢時，該對象被刪除。

代碼，我正在錯誤：

public void deleteStorage(CommonLayer.TblNewsStorage storageToDelete) 
    { 
     using(DBTicketSystemEntities e = new DBTicketSystemEntities()) 
     { 
      e.TblNewsStorage.DeleteObject(storageToDelete); 
      e.SaveChanges(); 
     } 
    } 

堆棧跟蹤：

[InvalidOperationException: The object cannot be deleted because it was not found in the ObjectStateManager.] 
    System.Data.Objects.ObjectContext.DeleteObject(Object entity, EntitySet expectedEntitySet) +3061568 
    System.Data.Objects.ObjectSet`1.DeleteObject(TEntity entity) +18 
    DataLayer.DAStorage.deleteStorage(TblNewsStorage storageToDelete) in C:\Users\Eric\Desktop\Development\Library News\LibraryNews\DataLayer\DAStorage.cs:38 
    BusinessLayer.Storage.deleteStorage(String id) in C:\Users\Eric\Desktop\Development\Library News\LibraryNews\BusinessLayer\Storage.cs:43 
    NewsLibrary.Controllers.StorageController.Delete(TblNewsStorage storage) in C:\Users\Eric\Desktop\Development\Library News\LibraryNews\NewsLibrary\Controllers\StorageController.cs:61 
    lambda_method(Closure , ControllerBase , Object[]) +180 
    System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14 
    System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208 
    System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27 
    System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28 
    System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +48 
    System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +57 
    System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +223 
    System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +10 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +48 
    System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24 
    System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43 
    System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47 
    System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10 
    System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47 
    System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9 
    System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9688704 
    System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155 

Answer 1

嘗試發送要刪除的對象的ID，然後在您的上下文中查詢它，而不是發送整個對象：

public void deleteStorage(int ID) 
{ 
    using(DBTicketSystemEntities e = new DBTicketSystemEntities()) 
    { 
     //Like That 
     var selectedItem = e.TblNewsStorage.Where(t => t.ID == ID).FirstOrDefault(); 
     e.TblNewsStorage.DeleteObject(selectedItem); 
     e.SaveChanges(); 
    } 
} 

Answer 2

試試下面的代碼： -

e.TblNewsStorage(storageToDelete).State = System.Data.EntityState.Deleted; 
e.SaveChanges(); 

OR

e.TblNewsStorage.Attach(storageToDelete); 
e.TblNewsStorage.Remove(storageToDelete); 
e.SaveChanges();