Syncfusion sfDatagrid 的 Catel UIVisualizerService 问题

Question

我创建了一个使用 Catel、Entity Framework6 和 Syncfusion Community Edition 的项目。具体来说，我使用的是 Syncfusion 的 sfDataGrid。

我遇到了一个让我完全难过的问题，也许有人能给我指出正确的方向。

我有一个带有 sfDataGrid 的 Catel UserControl。 ViewModel 具有我用作 sfDataGrid 的 ItemsSource 的数据的 ObservableCollection (Catel 属性)。我在 sfDataGrid 上启用了过滤。这是 sfDataGrid 的代码：

<sync:SfDataGrid
                x:Name="ItemsDataGrid"
                ItemsSource="{Binding MyItems, Mode=OneWay}"
                SelectedItem="{Binding MyItem, Mode=TwoWay}"
                AutoGenerateColumns="False"
                AllowFiltering="True"
                AllowResizingColumns="True"
                GridCopyOption="IncludeHeaders"
                GridPasteOption="None"
                ShowGroupDropArea="True"
                ShowRowHeader="True"
                DataFetchSize="50">
<!-- Columns -->
</sync:SfDataGrid>

我在不同的视图中向 collection 添加了一个新项目，然后将其保存到数据上下文并刷新列表：

private async void OnNewMyItemExecute()
        {
            MyItem= new MyItem();

            MyItemsRepository.Add(MyItem);

            var myItemsViewModel = TypeFactory
                .Default
                .CreateInstanceWithParametersAndAutoCompletion<myItemsViewModel >(MyItem); //the construction has parameters for IUIVisualizerService, IPleaseWaitService, etc.

            if (await _UIVisualizerService.ShowDialogAsync(myItemsViewModel) ?? true)
            {
                var myItem= myItemsViewModel.MyItem;

                await InitializeAsync();

                MyItem = myItem;
            }
            else
            {
                _UnitOfWorkService.Rollback(); //just undo some changes
                MyItem = null;
            }

            UnitOfWork.SaveChanges();
        }

创建一个新项目根本不是问题，奇怪的是，在我创建一个新项目之后，然后尝试在 sfDataGrid 的任何列上筛选网格（单击列中的筛选按钮 header，将打开一个过滤器弹出窗口，在条件文本框中输入一个值并单击 'OK')，我明白了：

MyProject.vshost.exe Warning: 0 : 17:57:49:075 => [WARNING] [Catel.Services.UIVisualizerService] [8] An error occurred, returning null since we don't know the result | [TargetInvocationException] System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidCastException: Unable to cast object of type 'MyProject.Domain.MyItem' to type 'System.Data.Entity.DynamicProxies.MyItem_4CA6F59AB53174892ED9EFBC1D3CC07B862579FC3C5733C6CF4DE857907CFF9C'. at lambda_method(Closure , MyItem ) --- End of inner exception stack trace --- at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Delegate.DynamicInvoke(Object[] args) at Syncfusion.Data.QueryableCollectionView.<>c__DisplayClass3.b__1(Object o) at Syncfusion.Data.QueryableCollectionView.FilterRecord(Object record) at Syncfusion.Data.EnumerableRecordsWrapper..ctor(IEnumerable source, CollectionViewAdv view) at Syncfusion.Data.EnumerableRecordsWrapper.CreateNew(IEnumerable source, CollectionViewAdv view) at Syncfusion.Data.QueryableCollectionView.CreateRecords() at Syncfusion.Data.CollectionViewAdv.EnsureInitialized() at Syncfusion.Data.CollectionViewAdv.get_Records() at Syncfusion.Data.CollectionViewAdv.EnsureRecordsInitialized() at Syncfusion.Data.CollectionViewAdv.Refresh() at Syncfusion.Data.QueryableCollectionView.RefreshFilter() at Syncfusion.Data.CollectionViewAdv.ApplyFilters() at Syncfusion.Data.CollectionViewAdv.set_FilterPredicates(ObservableCollection1 value) at Syncfusion.UI.Xaml.Grid.GridModel.FilterColumn(GridColumn column, List1 filterPredicates) at Syncfusion.UI.Xaml.Grid.GridFilterControl.RefreshFilter() at Syncfusion.UI.Xaml.Grid.GridFilterControl.b__10(Object s, RunWorkerCompletedEventArgs e) at System.ComponentModel.BackgroundWorker.OnRunWorkerCompleted(RunWorkerCompletedEventArgs e) at System.ComponentModel.BackgroundWorker.AsyncOperationCompleted(Object arg) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.DispatcherOperation.InvokeImpl() at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Threading.DispatcherOperation.Invoke() at System.Windows.Threading.Dispatcher.ProcessQueue() at System.Windows.Threading.Dispatcher.WndProcHook(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 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Window.ShowHelper(Object booleanBox) at System.Windows.Window.Show() at System.Windows.Window.ShowDialog() --- End of inner exception stack trace --- at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) at Catel.Services.UIVisualizerService.<>c__DisplayClass23_0.b__0() in C:\CI_WS\Ws058\Source\Catel\src\Catel.MVVM\Catel.MVVM.Shared\Services\UIVisualizerService.cs:line 499

这是 UIVisualizerService 的方法，第 499 行：

protected virtual bool? ShowWindow(FrameworkElement window, bool showModal)
        {
            if (showModal)
            {
                var showDialogMethodInfo = window.GetType().GetMethodEx("ShowDialog");
                if (showDialogMethodInfo != null)
                {
                    // Child window does not have a ShowDialog, so not null is allowed
                    bool? result = null;

                    window.Dispatcher.InvokeIfRequired(() =>
                    {
                        // Safety net to prevent crashes when this is the main window
                        try
                        {
                            result = showDialogMethodInfo.Invoke(window, null) as bool?; //Line 499
                        }
                        catch (Exception ex)
                        {
                            Log.Warning(ex, "An error occurred, returning null since we don't know the result");
                        }
                    });

                    return result;
                }

                Log.Warning("Method 'ShowDialog' not found on '{0}', falling back to 'Show'", window.GetType().Name);
            }

我曾尝试使用 .ShowAsync()、.ShowDialogAsync() 打开 MyItemsView，在升级到 Catel 4.4 之前我还使用了 .ShowDialog()，但没有任何区别。我可以在 EF 中关闭代理创建，但这会导致我必须在我的项目中进行大量更改（对我来说不再需要延迟加载，这不是一个选项）。我相信问题是我添加的新项目不是动态代理，让它成为动态代理可能会解决这个问题，但我已经尝试再次从 DbContext 加载所有数据，但它也没有解决问题。

如有任何建议，我们将不胜感激。

Answer 1

问题是这样的：

System.InvalidCastException: Unable to cast object of type 'MyProject.Domain.MyItem' to type 'System.Data.Entity.DynamicProxies.MyItem_4CA6F59AB53174892ED9EFBC1D3CC07B862579FC3C5733C6CF4DE857907CFF9C'.

当然，原因是您试图将基类型转换为派生类型（事实并非如此）。这最终导致 window 关闭是因为发生了异常，但这不是真正的问题。

此异常发生在网格的FilterRecord 方法中。我不确定那是你自己写的还是 syncfusion 里面的东西，但这是值得一看的地方。

您生成代理的原因是您启用（或默认启用）Entity Framework DbContext 的代理生成。

Syncfusion sfDatagrid 的 Catel UIVisualizerService 问题

Catel UIVisualizerService issue with Syncfusion sfDatagrid

syncfusion

entity-framework-6

catel