Hi Frank,

I realize this is not timely, but I am curious about something. You are creating a business object and retrieving a list of items that are bound to your grid. Not using View Model I take it also. Then when you want to delete, you are retrieving an additional entity from a new business object so you can delete it. Why not delete it from the original list of entity objects that you retrieved? Then once they are all deleted in that list, you can call saveEntityList on the same business object which will take care of the deletes for you.

>I have solved this by changing a setting on the oRND object: oRND.ImmediateDelete = true;
>
>This allows the item to be actually deleted, rather than just tagging it for deletion and relying on the save to run afterwards.
>
>Hi,
>
>I have a XAML application done in MM.NET using C#. I am displaying a form with 2 business objects created like this:
>
>

    public partial class RunSheetsWindow : ABusinessWindow
>    {
>        private RunSheetHeader oRunSheetHeader;
>        private RunSheetDetails oRunSheetDetails;
>.
>.
>.
>        public RunSheetsWindow()
>        {
>            this.RouteSearch = (Route)this.RegisterBizObj(new Route());
>            this.Route = (Route)this.RegisterBizObj(new Route());
>
>            this.oRunSheetHeader = (RunSheetHeader)this.RegisterPrimaryBizObj(new RunSheetHeader());
>            this.oRunSheetDetails = (RunSheetDetails)this.RegisterBizObj(new RunSheetDetails());
>            this.oRunSheetHeader.RegisterChildBizObj(this.oRunSheetDetails);
>

>
>The form displays the Run Sheet Header and all the items that belong to the run sheet. The details are displayed in a grid and I want to let a user select an item in the grid and remove it (ie delete it from the underlying table).
>
>This is the code I use to display/bind the data to the grid:
>
>

this.grdRunSheetDetails.DataContext = this.oRunSheetDetails.DataSet.Tables[this.oRunSheetDetails.TableName].DefaultView;

>
>Here is the code I use to delete the items that are selected:
>
>

                    RunSheetDetails oRND = new RunSheetDetails();
>
>                    foreach (DataRowView oRow in this.grdRunSheetDetails.SelectedItems)
>                    {
>                        oRND.GetRunSheetDetailsByPK((Guid)oRow.Row["rnd_pk"]);
>                        oRND.Delete((Guid)oRow.Row["rnd_pk"]);
>                        
>                        mmSaveDataResult saveResult = oRND.SaveEntity();
>                    }
>

>
>This crashes with this error:
>
>System.NullReferenceException was unhandled by user code
> HResult=-2147467261
> Message=Object reference not set to an instance of an object.
> Source=SamaanSystems.IBC.Business
> StackTrace:
> at SamaanSystems.IBC.Business.RunSheetDetailsRules.CheckRulesHook[EntityType](mmBindingList`1 entityList) in D:\Development\VS2010\IBC\IBC Business Objects\RunSheetDetails\RunSheetDetailsRules.cs:line 41
> at OakLeaf.MM.Main.Business.mmBusinessRule.CheckRules[EntityType](mmBindingList`1 entityList, mmRulesType rulesType)
> at OakLeaf.MM.Main.Business.mmBusinessObjectGeneric`1.CheckRules(mmBusinessObjectGeneric`1 businessObject, mmBindingList`1 entityList, mmRulesType rulesType)
> at OakLeaf.MM.Main.Business.mmBusinessObjectGeneric`1.CheckRules(mmBusinessObjectGeneric`1 businessObject, mmBindingList`1 entityList)
> at OakLeaf.MM.Main.Business.mmBusinessObjectGeneric`1.SaveEntity(EntityType entity)
> at OakLeaf.MM.Main.Business.mmBusinessObjectGeneric`1.SaveEntity()
> at SamaanSystems.IBC.WPF.RunSheetsWindow.btnRemove_Click(Object sender, RoutedEventArgs e) in D:\Development\VS2010\IBC\IBC WPF\RunSheetsWindow.xaml.cs:line 225
> at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
> at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
> at System.Windows.Controls.Button.OnClick()
> at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
> at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
> at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
> at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
> at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
> at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
> at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
> at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
> at System.Windows.Input.InputManager.ProcessStagingArea()
> at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
> at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
> at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
> at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
> at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
> at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
> at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
> at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
> InnerException:
>
>
>This occurs in the last line of code below:
>
>

		public override bool CheckRulesHook<EntityType>(mmBindingList<EntityType> entityList)
>		{
>			// Call any generated rules
>			if (entityList != null)
>			{
>				foreach (EntityType CurrentEntity in entityList)
>				{
>					this.CurrentEntity = CurrentEntity as mmBusinessEntity;
>				
>					if (this.CurrentEntity.GetDataRow().RowState == DataRowState.Added ||
>					this.CurrentEntity.GetDataRow().RowState == DataRowState.Modified)
>

>
>If I don't call the SaveEntity, the item does not get removed from the grid nor deleted from the table.
>
>Any ideas how I am supposed to do this?