用戶有時候想要將一組撤銷和重做來作為一個單一的操作，FlowChart.NET提供了CompositeCmd類來幫助用戶實(shí)現(xiàn)這樣的需求。CompositeCmd對象作為其他派生命令對象的一個容器，當(dāng)撤銷或是重做包含在一個復(fù)合命令中時，所有的子命令就將會表現(xiàn)出撤銷或是重做。

    要添加一個命令老調(diào)用AddSubCmd方法，調(diào)用執(zhí)行方法來執(zhí)行包含在復(fù)合中的所有的子命令，子命令會被按照原來的被添加到容器中的順序執(zhí)行或是重做，并會被以相反的順序被撤銷。

    通常FlowChart.NET會隱式的產(chǎn)生命令對象以便于用戶響應(yīng)或是方法調(diào)用，并且在歷史隊列中自動的記錄。你不能直接的訪問這些命令，以及通過AddSubCmd添加它們到一個復(fù)合中。

C#

// Implicitly created undo records will be saved here
CompositeCmd composite = diagram.UndoManager.StartComposite("Create group");

// Call methods that create undo records
ShapeNode node1 = diagram.Factory.CreateShapeNode(0, 0, 30, 30);
ShapeNode node2 = diagram.Factory.CreateShapeNode (0, 0, 15, 15);
Group g = diagram.Factory.CreateGroup(node1);
g.AttachToCorner(node2, 0);

// This goes to the active composite too
ChangeItemCmd change = new ChangeItemCmd(node2, "");
node2.Locked = true;
change.Execute();

// Save the active composite in history
composite.Execute();

Visual Basic

' Implicitly created undo records will be saved here
Dim composite As CompositeCmd = Diagram.UndoManager.StartComposite("Create group")

' Call methods that create undo records
Dim node1 As ShapeNode = Diagram.Factory.CreateShapeNode(0, 0, 30, 30)
Dim node2 As ShapeNode = Diagram.Factory.CreateShapeNode(0, 0, 15, 15)
Dim g As Group = Diagram.Factory.CreateGroup(node1)
g.AttachToCorner(node2, 0)

' This goes to the active composite too
Dim change As New ChangeItemCmd(node2, "")
node2.Locked = True
change.Execute()

' Save the active composite in history
composite.Execute()