CommandTest_UndoRedo
....................\CommandTest_UndoRedo
....................\....................\App.config
....................\....................\App.xaml
....................\....................\App.xaml.cs
....................\....................\CommandHistoryItem.cs
....................\....................\CommandTest_UndoRedo.csproj
....................\....................\DrawingCanvas.cs
....................\....................\LoopOperation
....................\....................\.............\DrawDemo.cs
....................\....................\.............\IUndoRedo.cs
....................\....................\.............\StoreHistoryCollection.cs
....................\....................\MainWindow.xaml
....................\....................\MainWindow.xaml.cs
....................\....................\Properties
....................\....................\..........\AssemblyInfo.cs
....................\....................\..........\Resources.Designer.cs
....................\....................\..........\Resources.resx
....................\....................\..........\Settings.Designer.cs
....................\....................\..........\Settings.settings
....................\CommandTest_UndoRedo.sln
....................\CommandTest_UndoRedo.v12.suo
....................\Illustration.txt