stuframe.add(this,BorderLayout.WEST);为什么不加这句面板中所添加的按钮就显示不出来？？？这个this代表什么？？ 本人初学者，对JAVA ...

Developers often need to create graphical user interfaces (GUIs) that have a matrix-type layout with columns of different widths or rows of different heights. Those layout cells are unequal in order ...