组合键的使用就是只要在键盘上按下一定的键就能触发相应的事件-bond portfolio as long as the use is the keyboard by pressing a button will trigger corresponding events

创建Dictionary对象, 用来保存数据键和项目对，它实际上是一个比较开放的数组-create Dictionary object, used to store data and projects on the bond, it is actually a relatively open array