class myclass extends frame 窗口 Panel MyPanel p=new Mypanelo; add(p); Button b=new Button(exit) add(b); ok boolean action ●·。 exit class MyPanel extends Panel class MyBtn extends Button My Btn b= new Mybtn(“o”){ add(b) boolean action boolean action return true11 class MyPanel extends Panel { MyBtn b=new MyBtn(“ok”); add(b); boolean action() {…….;} } class MyClass extends Frame { MyPanel p=new Mypanel(); add(p); Button b=new Button(exit); add(b); boolean action() {…….;} } 窗口 exit class MyBtn extends Button { boolean action() { …….; return true;} } ok Panel