初始化项目

BLV_Studio/Undo/CommandManager.vb

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+Public Class CommandManager
+    Protected UndoCommands As New Stack(Of ICommand)
+
+    Protected RedoCommands As New Stack(Of ICommand)
+
+    ''' <summary>
+    ''' 运行命令，并将命令添加至撤销堆栈
+    ''' </summary>
+    ''' <param name="command"></param>
+    Public Sub RunCommand(command As ICommand)
+        command.Redo()
+        AddUndoCommand(command)
+    End Sub
+
+    ''' <summary>
+    ''' 将命令添加至撤销堆栈
+    ''' </summary>
+    Public Sub AddUndoCommand(command As ICommand)
+        UndoCommands.Push(command)
+        If RedoCommands.Count > 0 Then
+            ClearRedoCommands()
+        End If
+    End Sub
+
+    ''' <summary>
+    ''' 清空撤销命令堆栈
+    ''' </summary>
+    Public Sub ClearUndoCommands()
+        UndoCommands.Clear()
+    End Sub
+
+    ''' <summary>
+    ''' 清空重做命令堆栈
+    ''' </summary>
+    Public Sub ClearRedoCommands()
+        RedoCommands.Clear()
+    End Sub
+
+    ''' <summary>
+    ''' 清空撤销与重做命令堆栈
+    ''' </summary>
+    Public Sub ClearCommands()
+        ClearUndoCommands()
+        ClearRedoCommands()
+    End Sub
+
+    ''' <summary>
+    ''' 执行撤销命令
+    ''' </summary>
+    Public Sub Undo()
+        If UndoCommands.Count <= 0 Then Return
+        Dim command As ICommand = UndoCommands.Pop()
+        command.Undo()
+        RedoCommands.Push(command)
+    End Sub
+
+
+    ''' <summary>
+    ''' 执行重做命令
+    ''' </summary>
+    Public Sub Redo()
+        If RedoCommands.Count <= 0 Then Return
+
+        Dim command As ICommand = RedoCommands.Pop()
+        command.Redo()
+
+        UndoCommands.Push(command)
+    End Sub
+End Class

BLV_Studio/Undo/ICommand.vb

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+Public Interface ICommand
+    ''' <summary>
+    ''' 重做命令
+    ''' </summary>
+    Sub Redo()
+
+    ''' <summary>
+    ''' 撤销命令
+    ''' </summary>
+    Sub Undo()
+End Interface