事件处理的原则
 
 

It is important to remember that events simply provide information on the state or activities taking place within AutoCAD. Although event handlers can be written to respond to those events, AutoCAD might be in the middle of an operation when the event handler is triggered. Event handlers, therefore, have some restrictions on what they can do if they are to provide safe operations in conjunction with AutoCAD and its database.

需要记住的是,事件只是提供了 AutoCAD 内部发生的状态或动作信息。虽然事件处理程序可以响应这些事件,但触发事件处理程序时,AutoCAD 通常都是正处在处理命令的执行过程中。因此,如果要使事件处理程序在涉及 AutoCAD 及其数据库时提供安全的操作,则需要对事件处理程序进行一些限制。