[界面说明] 下拉列表框,选谁谁显示.复选框与单选按钮,输出被选与否的状态.知识点主要代码为: int state = e.getStateChange(); ItemEvent.SELECTED ItemEvent.DESELECTED public class Demo extends JFrame { public Demo() { setBounds(100, 100, 300, 150); setDefaultCloseOperation(WindowConstants.EXIT_
var hiddenProperty ='hidden' in document ? 'hidden' :'webkitHidden' in document ? 'webkitHidden' : 'mozHidden' in document ? 'mozHidden' : null; var visibilityChangeEvent = hiddenProperty.replace(/hidden/i,'visibilitychange'); var onVisibilityChange