src

src/com/sheep/view/Game.java

@@ -36,7 +36,7 @@ public class Game extends JFrame {
         this.setTitle("java羊了个羊");//标题
         this.setSize(425,800);//窗口大小
 
-        //this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭java界面退出程序
+        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭java界面退出程序
         this.setLocationRelativeTo(null);//窗体剧中
 
         this.setLayout(null);//设置绝对布局

src/com/sheep/view/Start.java

@@ -47,6 +47,7 @@ public class Start extends JFrame {
             @Override
             public void actionPerformed(ActionEvent e) {
                 new Game();
+                Start.super.dispose();
             }
         });
     }