DevExpress-Examples · Alexander-Ploskin · Nov 1, 2021 · Nov 1, 2021 · Nov 2, 2021 · Nov 2, 2021
diff --git a/CS/ViewModel/EFCore/LocalData/IDataItemCopyOperationsSupporter.cs b/CS/ViewModel/EFCore/LocalData/IDataItemCopyOperationsSupporter.cs
@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EFCoreIssues {
+    public interface IDataItemCopyOperationsSupporter {
+        object Clone(object item);
+        void CopyTo(object source, object target);
+    }
+}
diff --git a/CS/ViewModel/EFCore/LocalData/LocalData.csproj b/CS/ViewModel/EFCore/LocalData/LocalData.csproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\..\..\packages\EntityFramework.6.4.4\build\EntityFramework.props" Condition="Exists('..\..\..\packages\EntityFramework.6.4.4\build\EntityFramework.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
@@ -13,7 +13,7 @@
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <WarningLevel>4</WarningLevel>
-	<TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <Deterministic>true</Deterministic>
     <NuGetPackageImportStamp>
@@ -166,11 +166,14 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </ApplicationDefinition>
+    <Compile Include="UndoBehavior.cs" />
+    <Compile Include="UserCopyOperationsSupporter.cs" />
     <Page Include="MainWindow.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
-    <Compile Include="MainViewModel.cs"/>
+    <Compile Include="IDataItemCopyOperationsSupporter.cs" />
+    <Compile Include="MainViewModel.cs" />
     <Compile Include="App.xaml.cs">
       <DependentUpon>App.xaml</DependentUpon>
       <SubType>Code</SubType>
@@ -213,4 +216,4 @@
     <None Include="App.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-</Project>
+</Project>
diff --git a/CS/ViewModel/EFCore/LocalData/MainViewModel.cs b/CS/ViewModel/EFCore/LocalData/MainViewModel.cs
@@ -1,18 +1,29 @@
 using DevExpress.Mvvm;
+using System.Collections.ObjectModel;
 using System.Linq;
 
 namespace EFCoreIssues {
     public class MainViewModel : ViewModelBase {
         EFCoreIssues.Issues.IssuesContext _Context;
-        System.Collections.Generic.IList<EFCoreIssues.Issues.User> _ItemsSource;
+        ObservableCollection<EFCoreIssues.Issues.User> _ItemsSource;
 
-        public System.Collections.Generic.IList<EFCoreIssues.Issues.User> ItemsSource
+        UserCopyOperationsSupporter _CopyOperationsSupporter;
+        public UserCopyOperationsSupporter CopyOperationsSupporter {
+            get {
+                if(_CopyOperationsSupporter == null) {
+                    _CopyOperationsSupporter = new UserCopyOperationsSupporter();
+                }
+                return _CopyOperationsSupporter;
+            }
+        }
+
+        public ObservableCollection<EFCoreIssues.Issues.User> ItemsSource
         {
             get
             {
                 if(_ItemsSource == null && !IsInDesignMode) {
                     _Context = new EFCoreIssues.Issues.IssuesContext();
-                    _ItemsSource = _Context.Users.ToList();
+                    _ItemsSource = new ObservableCollection<Issues.User>(_Context.Users);
                 }
                 return _ItemsSource;
             }

diff --git a/CS/ViewModel/EFCore/LocalData/MainWindow.xaml b/CS/ViewModel/EFCore/LocalData/MainWindow.xaml
@@ -1,31 +1,40 @@
-<Window x:Class="EFCoreIssues.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:EFCoreIssues" xmlns:local_issues="clr-namespace:EFCoreIssues.Issues" xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid" xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars" xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core" mc:Ignorable="d" Title="MainWindow" Height="450" Width="800">
-  <Grid>
-    <dxb:ToolBarControl>
-      <dxb:BarButtonItem Content="Refresh (F5)" Command="{Binding View.Commands.RefreshDataSource, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Refresh.svg}" BarItemDisplayMode="ContentAndGlyph" />
-      <dxb:BarButtonItem Content="Edit (F2)" Command="{Binding View.Commands.EditFocusedRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Edit.svg}" BarItemDisplayMode="ContentAndGlyph" />
-      <dxb:BarButtonItem Content="New" Command="{Binding View.Commands.AddNewRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Add.svg}" BarItemDisplayMode="ContentAndGlyph" />
-      <dxb:BarButtonItem Content="Delete (Del)" Command="{Binding View.Commands.DeleteFocusedRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Delete.svg}" BarItemDisplayMode="ContentAndGlyph" />
-    </dxb:ToolBarControl>
-    <dxg:GridControl x:Name="grid" ItemsSource="{Binding ItemsSource}" RestoreStateKeyFieldName="Id" RestoreStateOnSourceChange="True" Grid.Row="1">
-      <dxg:GridControl.View>
-        <dxg:TableView NewItemRowPosition="Top" ShowUpdateRowButtons="OnCellEditorOpen" ValidateRowCommand="{Binding ValidateRowCommand}" ValidateRowDeletionCommand="{Binding ValidateRowDeletionCommand}" DataSourceRefreshCommand="{Binding DataSourceRefreshCommand}" ShowFixedTotalSummary="True" />
-      </dxg:GridControl.View>
-      <dxg:GridColumn FieldName="Id" IsSmart="True" ReadOnly="True" />
-      <dxg:GridColumn FieldName="FirstName" IsSmart="True" />
-      <dxg:GridColumn FieldName="LastName" IsSmart="True" />
-      <dxg:GridControl.InputBindings>
-        <KeyBinding Command="{Binding View.Commands.DeleteFocusedRow, ElementName=grid}" Key="Delete" />
-      </dxg:GridControl.InputBindings>
-      <dxg:GridControl.TotalSummary>
-        <dxg:GridSummaryItem SummaryType="Count" Alignment="Right" />
-      </dxg:GridControl.TotalSummary>
-    </dxg:GridControl>
-    <Grid.RowDefinitions>
-      <RowDefinition Height="Auto" />
-      <RowDefinition />
-    </Grid.RowDefinitions>
-  </Grid>
-  <Window.DataContext>
-    <local:MainViewModel />
-  </Window.DataContext>
+<Window x:Class="EFCoreIssues.MainWindow"   xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:EFCoreIssues" xmlns:local_issues="clr-namespace:EFCoreIssues.Issues" xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid" xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars" xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core" mc:Ignorable="d" Title="MainWindow" Height="450" Width="800">
+    <Window.DataContext>
+        <local:MainViewModel />
+    </Window.DataContext>
+    <Grid>
+        <dxb:ToolBarControl>
+            <dxb:BarButtonItem Content="Refresh (F5)" Command="{Binding View.Commands.RefreshDataSource, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Refresh.svg}" BarItemDisplayMode="ContentAndGlyph" />
+            <dxb:BarButtonItem Content="Edit (F2)" Command="{Binding View.Commands.EditFocusedRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Edit.svg}" BarItemDisplayMode="ContentAndGlyph" />
+            <dxb:BarButtonItem Content="New" Command="{Binding View.Commands.AddNewRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Add.svg}" BarItemDisplayMode="ContentAndGlyph" />
+            <dxb:BarButtonItem Content="Delete (Del)" Command="{Binding View.Commands.DeleteFocusedRow, ElementName=grid}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Delete.svg}" BarItemDisplayMode="ContentAndGlyph" />
+            <dxb:BarButtonItem Content="Undo (Ctrl+Z)" Command="{Binding UndoCommand, ElementName=undoBehavior}" Glyph="{dx:DXImage SvgImages/Icon Builder/Actions_Undo.svg}" BarItemDisplayMode="ContentAndGlyph" />
+        </dxb:ToolBarControl>
+        <dxg:GridControl x:Name="grid" ItemsSource="{Binding ItemsSource}" RestoreStateKeyFieldName="Id" RestoreStateOnSourceChange="True" Grid.Row="1">
+            <dxg:GridControl.View>
+                <dxg:TableView NewItemRowPosition="Top" ShowUpdateRowButtons="OnCellEditorOpen" ValidateRowCommand="{Binding ValidateRowCommand}" ValidateRowDeletionCommand="{Binding ValidateRowDeletionCommand}" DataSourceRefreshCommand="{Binding DataSourceRefreshCommand}" ShowFixedTotalSummary="True" >
+                    <dxmvvm:Interaction.Behaviors>
+                        <local:UndoBehavior x:Name="undoBehavior"
+                                            ValidateRowCommand="{Binding ValidateRowCommand}"
+                                            ValidateRowDeletionCommand="{Binding ValidateRowDeletionCommand}"
+                                            CopyOperationsSupporter="{Binding CopyOperationsSupporter}" />
+                    </dxmvvm:Interaction.Behaviors>
+                </dxg:TableView>
+            </dxg:GridControl.View>
+            <dxg:GridColumn FieldName="Id" IsSmart="True" ReadOnly="True" />
+            <dxg:GridColumn FieldName="FirstName" IsSmart="True" />
+            <dxg:GridColumn FieldName="LastName" IsSmart="True" />
+            <dxg:GridControl.InputBindings>
+                <KeyBinding Command="{Binding View.Commands.DeleteFocusedRow, ElementName=grid}" Key="Delete" />
+                <KeyBinding Command="{Binding UndoCommand, ElementName=undoBehavior}" Key="Z" Modifiers="Ctrl" />
+            </dxg:GridControl.InputBindings>
+            <dxg:GridControl.TotalSummary>
+                <dxg:GridSummaryItem SummaryType="Count" Alignment="Right" />
+            </dxg:GridControl.TotalSummary>
+        </dxg:GridControl>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
+            <RowDefinition />
+        </Grid.RowDefinitions>
+    </Grid>
 </Window>
diff --git a/CS/ViewModel/EFCore/LocalData/UndoBehavior.cs b/CS/ViewModel/EFCore/LocalData/UndoBehavior.cs
@@ -0,0 +1,128 @@
+using DevExpress.Mvvm;
+using DevExpress.Mvvm.UI.Interactivity;
+using DevExpress.Mvvm.Xpf;
+using DevExpress.Xpf.Grid;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Input;
+
+namespace EFCoreIssues {
+    public class UndoBehavior : Behavior<TableView> {
+        public static readonly DependencyProperty CopyOperationsSupporterProperty =
+           DependencyProperty.Register(nameof(CopyOperationsSupporter), typeof(IDataItemCopyOperationsSupporter), typeof(UndoBehavior), new PropertyMetadata(null));
+
+        public IDataItemCopyOperationsSupporter CopyOperationsSupporter {
+            get { return (IDataItemCopyOperationsSupporter)GetValue(CopyOperationsSupporterProperty); }
+            set { SetValue(CopyOperationsSupporterProperty, value); }
+        }
+
+        public static readonly DependencyProperty ValidateRowCommandProperty =
+          DependencyProperty.Register(nameof(ValidateRowCommand), typeof(ICommand<RowValidationArgs>), typeof(UndoBehavior), new PropertyMetadata(null));
+
+        public ICommand<RowValidationArgs> ValidateRowCommand {
+            get { return (ICommand<RowValidationArgs>)GetValue(ValidateRowCommandProperty); }
+            set { SetValue(ValidateRowCommandProperty, value); }
+        }
+
+        public static readonly DependencyProperty ValidateRowDeletionCommandProperty =
+        DependencyProperty.Register(nameof(ValidateRowDeletionCommand), typeof(ICommand<ValidateRowDeletionArgs>), typeof(UndoBehavior), new PropertyMetadata(null));
+
+        public ICommand<ValidateRowDeletionArgs> ValidateRowDeletionCommand {
+            get { return (ICommand<ValidateRowDeletionArgs>)GetValue(ValidateRowDeletionCommandProperty); }
+            set { SetValue(ValidateRowDeletionCommandProperty, value); }
+        }
+
+        public ICommand UndoCommand { get; private set; }
+
+        public UndoBehavior() {
+            UndoCommand = new DelegateCommand(Undo, CanUndo);
+        }
+
+        IList source;
+
+        protected override void OnAttached() {
+            base.OnAttached();
+            AssociatedObject.ValidateRow += OnRowAddedOrEdited;
+            AssociatedObject.ValidateRowDeletion += OnRowDeleted;
+            AssociatedObject.RowEditStarted += OnEditingStarted;
+            AssociatedObject.DataSourceRefresh += OnRefresh;
+            AssociatedObject.InitNewRow += OnNewRowStarted;
+            source = (IList)AssociatedObject.DataControl.ItemsSource;
+        }
+
+        private void OnRefresh(object sender, DataSourceRefreshEventArgs e) {
+            undoAction = null;
+            editingCache = null;
+        }
+
+        protected override void OnDetaching() {
+            AssociatedObject.ValidateRow -= OnRowAddedOrEdited;
+            AssociatedObject.ValidateRowDeletion -= OnRowDeleted;
+            AssociatedObject.RowEditStarted -= OnEditingStarted;
+            AssociatedObject.DataSourceRefresh -= OnRefresh;
+            AssociatedObject.InitNewRow -= OnNewRowStarted;
+            source = null;
+            base.OnDetaching();
+        }
+
+        private void OnNewRowStarted(object sender, InitNewRowEventArgs e) {
+            isNewItemRowEditing = true;
+        }
+
+        bool isNewItemRowEditing;
+
+        object editingCache;
+
+        private void OnEditingStarted(object sender, RowEditStartedEventArgs e) {
+            if(e.RowHandle != DataControlBase.NewItemRowHandle) {
+                editingCache = CopyOperationsSupporter.Clone(e.Row);
+            }
+        }
+
+        private void OnRowDeleted(object sender, GridValidateRowDeletionEventArgs e) {
+            undoAction = new Action(() => {
+                InsertItem(e.RowHandles.Single(), CopyOperationsSupporter.Clone(e.Rows.Single())); //Somehow index is changing after a new adding to source
+            });
+        }
+
+        private void OnRowAddedOrEdited(object sender, GridRowValidationEventArgs e) {
+            var item = e.Row;
+            undoAction = e.IsNewItem ? new Action(() => RemoveItem(item)) : new Action(() => ApplyEditingCache(item));
+            isNewItemRowEditing = false;
+        }
+
+        void ApplyEditingCache(object item) {
+            CopyOperationsSupporter.CopyTo(editingCache, item);
+            AssociatedObject.DataControl.RefreshRow(source.IndexOf(item)); //TODO: find a way how to get row handle by element or list index
+            ValidateRowCommand.Execute(new RowValidationArgs(editingCache, source.IndexOf(item), false, new CancellationToken(), false));
+        }
+
+        Action undoAction;
+
+        void Undo() {
+            undoAction?.Invoke();
+            undoAction = null;
+        }
+
+        bool CanUndo() {
+            return undoAction != null && !AssociatedObject.IsEditing && !isNewItemRowEditing && !AssociatedObject.IsDataSourceRefreshing;
+        }
+
+        void RemoveItem(object item) {
+            source.Remove(item);
+            ValidateRowDeletionCommand.Execute(new ValidateRowDeletionArgs(new object[] { item }, new int[] { source.IndexOf(item) }));
+        }
+
+        void InsertItem(int position, object item) {
+            source.Insert(position, item);
+            ValidateRowCommand.Execute(new RowValidationArgs(item, source.IndexOf(item), true, new CancellationToken(), false));
+        }
+
+    }
+}
diff --git a/CS/ViewModel/EFCore/LocalData/UndoManager.cs b/CS/ViewModel/EFCore/LocalData/UndoManager.cs
@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EFCoreIssues {
+    public class UndoManager {
+
+    }
+}
diff --git a/CS/ViewModel/EFCore/LocalData/UserCopyOperationsSupporter.cs b/CS/ViewModel/EFCore/LocalData/UserCopyOperationsSupporter.cs
@@ -0,0 +1,32 @@
+using EFCoreIssues.Issues;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EFCoreIssues {
+    public class UserCopyOperationsSupporter : IDataItemCopyOperationsSupporter {
+        public object Clone(object item) {
+            var userItem = GetUser(item);
+            return new User() { FirstName = userItem.FirstName, Id = userItem.Id, Issues = userItem.Issues, LastName = userItem.LastName };
+        }
+
+        public void CopyTo(object source, object target) {
+            var userSource = GetUser(source);
+            var userTarget = GetUser(target);
+            userTarget.FirstName = userSource.FirstName;
+            userTarget.Id = userSource.Id;
+            userTarget.Issues = userSource.Issues;
+            userTarget.LastName = userSource.LastName;
+        }
+
+        User GetUser(object item) {
+            var result = item as User;
+            if(result == null) {
+                throw new InvalidOperationException();
+            }
+            return result;
+        }
+    }
+}
diff --git a/README.md b/README.md
@@ -1,5 +1,4 @@
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