关键词: Undo/Redo, 事务, 触发器, 一致性维护, 关联操作

Abstract: In CAX system, for complex operation and related operation, existing Undo/Redo mechanism is difficult to ensure the Undo/Redo operation semantic consistency, avoid the destruction of graphic data, thus it leads to realize specific methods of Undo/Redo and further development difficultly. This paper analyzes the characteristics of complex and related operation in CAX systems, discusses the atomicity and consistency of transaction and the reactor mechanism, introduces the transaction-based to ensure the Undo/Redo operation semantic consistency and the reactor mechanism to reduce the relationship and complexity of operations as the resolution method, and describes the concrete implementation process and main algorithms. A case analysis in large-scale CAD software shows the effectiveness of the strategy．

Key words: Undo/Redo, transaction, reactor, consistency maintenance, related operations