wpf - 此 View 不允许“EditItem” - WPF 数据编辑问题

Question

我有一个 TreeView 学生。我在 TreeView 中的项目是类(class)中学生的姓名。在 TreeView 中选择一个项目时，我的 DataGrid“StudentDetails”中的数据应该发生变化。我的 DataGrid 有两列“Parameter_Details”和“Details”。第二列详细信息应该是可编辑的。行可能会根据 TreeViewItem 的选择而变化。

例如，我的 TreeView 有两个项目，例如
jack
吉尔

当我单击/选择 Jack 时，我的 DataGrid“学生详细信息”显示 1 行两列“Parameter_Details”列下的字符串“Address”和“详细信息”列下的 string.Empty

地址|

当我单击/选择 Jill 时，我的 DataGrid“StudentDetails”显示 2 行两列第一行:“Parameter_Details”列下的字符串“Last Name”和“详细信息”列下的 string.Empty第二行:“Parameter_Details”列下的字符串“Address”和“Details”列下的 string.Empty姓氏|地址 |

我正在使用 foreach 循环将数据添加到我的数据网格中。我从数据库中获取“ParameterDetails”，其中每行都有与 TreeviewItem 对应的参数

每当我选择 TreeviewItem 时，我都会执行附加的代码:

dgStudentDetails.Items.Clear();

foreach (Parameter_Details entry in ParameterDetails)
{
    if(entry.ID == SelectedTVItem.ID)
    {
        dgKeywordParameters.Items.Add(new Parameter_dgInput() { name = entry.Name, input = "" });
    }
}

数据被绑定(bind)到数据网格，但是当我尝试使用编辑第二列时

private void DataGridCell_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    DataGridCell cell = sender as DataGridCell;

    if (cell != null && !cell.IsEditing && !cell.IsReadOnly)
    {
        // enables editing on single click
        if (!cell.IsFocused)
        cell.Focus();

        DataGrid dataGrid = UIHelpers.TryFindParent<DataGrid>(cell);

       if (dataGrid != null)
        {
             if (dataGrid.SelectionUnit != DataGridSelectionUnit.FullRow)
             {
                 if (!cell.IsSelected)
                      cell.IsSelected = true;
             }
             else
             {
                  DataGridRow row = UIHelpers.TryFindParent<DataGridRow>(cell);
                  if (row != null && !row.IsSelected)
                  {
                      row.IsSelected = true;
                  }
             }
        }
    }
}

我收到以下错误:

System.InvalidOperationException was unhandled
  Message='EditItem' is not allowed for this view.
  Source=PresentationFramework
  StackTrace:
       at System.Windows.Controls.ItemCollection.System.ComponentModel.IEditableCollectionView.EditItem(Object item)
       at System.Windows.Controls.DataGrid.EditRowItem(Object rowItem)
       at System.Windows.Controls.DataGrid.OnExecutedBeginEdit(ExecutedRoutedEventArgs e)
       at System.Windows.Controls.DataGrid.OnExecutedBeginEdit(Object sender, ExecutedRoutedEventArgs e)
       at System.Windows.Input.CommandBinding.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
       at System.Windows.Input.CommandManager.ExecuteCommandBinding(Object sender, ExecutedRoutedEventArgs e, CommandBinding commandBinding)
       at System.Windows.Input.CommandManager.FindCommandBinding(CommandBindingCollection commandBindings, Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
       at System.Windows.Input.CommandManager.FindCommandBinding(Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
       at System.Windows.Input.CommandManager.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
       at System.Windows.UIElement.OnExecutedThunk(Object sender, ExecutedRoutedEventArgs e)
       at System.Windows.Input.ExecutedRoutedEventArgs.InvokeEventHandler(Delegate genericHandler, Object target)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
       at System.Windows.Input.RoutedCommand.ExecuteImpl(Object parameter, IInputElement target, Boolean userInitiated)
       at System.Windows.Input.RoutedCommand.Execute(Object parameter, IInputElement target)
       at System.Windows.Controls.DataGrid.BeginEdit(RoutedEventArgs editingEventArgs)
       at System.Windows.Controls.DataGridCell.OnAnyMouseLeftButtonDown(MouseButtonEventArgs e)
       at System.Windows.Controls.DataGridCell.OnAnyMouseLeftButtonDownThunk(Object sender, MouseButtonEventArgs e)
       at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       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.UIElement.OnMouseDownThunk(Object sender, MouseButtonEventArgs e)
       at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       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.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
       at System.Windows.Input.InputManager.ProcessStagingArea()
       at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
       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)
       at System.Windows.Threading.Dispatcher.InvokeImpl(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.Application.RunDispatcher(Object ignore)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run(Window window)
       at System.Windows.Application.Run()
       at EBS.App.Main() in C:\projects\EBS\EBS\obj\x86\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

Answer 1

我也遇到过这个错误。看来同一错误消息有多种可能的原因。

我认为在你的情况下，做我所做的可能会起作用。我认为问题是，如果绑定(bind)数据不是允许编辑的类型之一，DataGrid 在编辑数据时会抛出此错误。

对我来说似乎效果很好的是，如果我创建一个新的列表，其中包含我想要显示的内容(可能是我为此目的创建的类，我在其中定义网格中的每一列)，然后将 DataGrid 绑定(bind)到该列表。

您可以在以下位置查看我对此的问答: Why does one of MY WPF DataGrids give the "'EditItem' is not allowed for this view" exception?