Exception in thread "AWT-EventQueue-1" java.lang.NoSuchMethodError: Mycanvas.setL(I)V at Example5.actionPerformed(Example5.java:88) at java.awt.Button.processActionEvent(Unknown Source) at java.awt.Button.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source)   
请问这是什么意思 就是Button 不能被监听 后