JAVA语言程序设计源代码 清华大学版

1.import java.applet.Applet; 2.import java.awt.*; 3.import java.awt.event.*; 4.public class Use6 extends Applet implements ActionListener 5.{Button a=new Button("+"),sub=new Button("-"), 6. plus=new Button("×"),div=new Button("÷"); 7.TextField t1=new TextField(12),t2=new TextField(12),t3=new TextField(12); 8.Label l1=new Label("操作数"),l2=new Label("操作数"),l3=new Label("结果"); 9.String s1,s2;double t; 10.Panel p1=new Panel(),p2=new Panel(); 11.public void init() 12.{a.addActionListener(this); sub.addActionListener(this); 13. plus.addActionListener(this);div.addActionListener(this); 14. //setLayout(new FlowLayout()); //总体布局 15.p1.setLayout(new GridLayout(3,2)); 16. p1.add(l1); p1.add(t1); p1.add(l2); p1.add(t2); p1.add(l3); p1.add(t3); 17. p2.setLayout(new GridLayout(4,1)); 18. p2.add(a);p2.add(sub); p2.add(plus); p2.add(div); 19. add(p1);add(p2);} 20.public void actionPerformed(ActionEvent e) 21.{s1=t1.getText();s2=t2.getText(); 22. if(e.getSource()==a) 23. {t=Double.parseDouble(s1)+Double.parseDouble(s2); 24. t3.setText("");t3.setText(Double.toString(t));} 25. if(e.getSource()==sub) 26. {t=Double.parseDouble(s1)-Double.parseDouble(s2); 27. t3.setText("");t3.setText(Double.toString(t));} 28. if(e.getSource()==plus) 29. {t=Double.parseDouble(s1)*Double.parseDouble(s2); 30. t3.setText("");t3.setText(Double.toString(t));} 31. if(e.getSource()==div) 32. {t=Double.parseDouble(s1)/Double.parseDouble(s2); 33. t3.setText("");t3.setText(Double.toString(t));} }} 34.//6．设计一个简单计算器，如下图所示。在“操作数”标签右侧的两个文本框输入操作数，当单击操作符＋，－，×，÷按钮时， 35.//对两个操作数进行运算并将结果填入到“结果”标签右侧的文本框中。