用java编写一个简易的计算器代码

1、import java.awt.BorderLayout;import java.awt.Color;import java.awt.GridLayout;import java.awt.eve nt.Act ion Eve nt;import java.awt.eve nt.Act ion Liste ner;import java.awt.eve nt.KeyEve nt;import java.awt.eve nt.KeyListe ner;import javax.swi ng.JButt on;import javax.swi ng.JFrame;import javax.swi n

2、g.JPa nel;import javax.swi ng.JTextField;/* 使用 java 语言开发一个简易计算器*/public class TestJsq exte nds JFrame impleme nts Actio nListe ner, KeyListe ner private JTextField jtf;private JButt on jb_bk, jb_ce, jb_c;private String xs =;private double sum = 0;private int fh;public static void main( Stri ng args)

3、 new TestJsq().creatCUI();public void creatCUI() JFrame jf = new JFrame();jf.setTitle( 计算器 );jtf = new JTextField(0.);jtf.setHorizo ntalAlig nmen t(JTextField.RIGHT);jf.add(jtf, BorderLayout.NORTH);JPa nel jp_ma in = new JPa nel( new BorderLayout(); jf.add(jp_ma in);JPa nel jp1 = new JPanel(new Grid

4、Layout(1,3, 1, 1); jb_bk = new JButto n( Backspace);jb_bk.setForegrou nd(Color.RED); jb_bk.addAct ion Liste ner(this); jb_ce = new JButto n( CE);jb_ce.setForegro un d(Color.RED);jb_ce.addAct ion Liste ner(this);jb_c = new JButto n( C);jb_c.setForegro un d(Color.RED); jb_c.addActi on Liste n er(this)

5、; jp1.add(jb_bk);jp1.add(jb_ce);jp1.add(jb_c);jp_mai n.add(jp1, BorderLayout.NORTH);JPa nel jp2 = new JPa nel( new GridLayout(4, 5,1,1);1 2 3 1/x 0 +/ + 一 String str 一 7, 8, 9, /, sqrt, 4, 5, 6, *, %,for (i nt i=:0; i 20; i+) JButton jb = new JButt on (stri);jb.addAct ion Liste n er(this);jb.setFore

6、gro un d(Color.blue);if (i 一一 3 | i 一一 8 | i 一一 13 | i 一一 18 | i 一一 19) jb.setForegro un d(Color.RED);jp2.add(jb);jp_mai n.add(jp2, BorderLayout.CENTER);jf.setResizable(false);jf.setBou nds(50, 50, 350, 350);jf.setVisible(true);Overridepublic void acti on Performed(Acti on Eve nt e) Stri ng s 一 e.ge

7、tAct ion Comma n d(); if (s.equals(CE) | s.equals(C) jtf.setText(0.); else if (s.equals(Backspace) Stri ng str 一 xs.substri n g(0, xsen gth() - 1); xs 一 str; jtf.setText(xs); else if (s.equals(7) | s.equals(8) | s.equals(9)| s.equals(4) | s.equals(5) | s.equals(6)| s.equals(1) | s.equals(2) | s.equa

8、ls(3)| s.equals(0) | s.equals(.) xs 一 xs + s;jtf.setText(xs); else if (s.equals(+/-) double x = Double.parseDouble(xs); xs= + (-x); jtf.setText(xs); else if (s.equals(/) fh = 4;int point = xs.i ndexOf(.);if (poi nt != -1) String strt = xs.substri ng(0, poin t);String z = xs.substri ng(po int + 1, xs

9、.len gth(); int z_num = z.len gth();sum = In teger.decode(strt) + (double) (In teger.decode(z) / (10 * z_n um); else sum = In teger.decode(xs); xs =; jtf.setText( null); else if (s.equals(*) fh = 3;int point = xs.i ndexOf(.);if (poi nt != -1) String strt = xs.substri ng(0, poin t);String z = xs.subs

10、tri ng(po int + 1, xs.len gth(); int z_num = z.len gth();sum = In teger.decode(strt) + (double) (In teger.decode(z) / (10 * z_nu m); else sum = In teger.decode(xs); xs =; jtf.setText( null); else if (s.equals(-) fh = 2;int point = xs.i ndexOf(.);if (poi nt != -1) String strt = xs.substri ng(0, poin

11、t);String z = xs.substri ng(po int + 1, xs.len gth(); int z_num = z.len gth();sum = In teger.decode(strt) + (double) (In teger.decode(z) / (10 * z_nu m); else sum = In teger.decode(xs);xs =; jtf.setText( null); else if (s.equals(+) fh = 1;int point = xs.i ndexOf(.);if (poi nt != -1) String strt = xs

12、.substri ng(0, poin t);String z = xs.substri ng(po int + 1, xs.len gth(); int z_num = z.len gth();sum = In teger.decode(strt) + (double) (In teger.decode(z) / (10 * z_nu m); else sum = In teger.decode(xs);xs =; jtf.setText( null); else if (s.equals(sqrt) double x = Double.parseDouble(xs);double x1 =

13、 Math.sqrt(x);xs = x1 + ;jtf.setText(xs); else if (s.equals(%) double x = Double.parseDouble(xs); x=0.01 * x*x;xs=x+; jtf.setText(xs); else if (s.equals(1/x) if (xs = 0) jtf.setText ( ”除数不能为 0); else double x = Double.parseDouble(xs);double x1 = 1 / x;xs = x1 + ;jtf.setText(Stri ng.valueOf(xs); else

14、 if (s.equals(=) if (fh != 0) switch (fh) case 1:in t poi nt1 = xs.i ndexOf(.);if (poi nt1 != -1) String s1 = xs.substri ng(0, poin t1);String z1 = xs.substri ng(po int1 + 1, xs.len gth();int z1_num = z1.len gth();xs =;double ss1 = In teger.decode(s1)+ (double) In teger.decode(z1) / (10 * z1_nu m);

15、sum = sum + ss1; else sum = sum + In teger.decode(xs); xs =;fh = 0;break;case 2:in t poi nt2 = xs.i ndexOf(.);if (poi nt2 != -1) String s2 = xs.substri ng(0, poin t2);String z2 = xs.substri ng(po int2 + 1, xs.len gth();int z2_num = z2.len gth();xs =;double ss2 = In teger.decode(s2)+ (double) In tege

16、r.decode(z2) / (10 * z2_num); sum = sum - ss2; else sum = sum - In teger.decode(xs); xs =;fh = 0;break;case 3:in t poi nt3 = xs.i ndexOf(.);if (poi nt3 != -1) String s3 = xs.substri ng(0, poin t3);String z3 = xs.substri ng(po int3 + 1, xs.len gth(); int z1_num = z3.len gth();xs =;double s4 = In tege

17、r.decode(s3)+ (double) In teger.decode(z3) / (10 * z1_num); sum = sum * s4; else sum = sum * In teger.decode(xs); xs =; fh = 0; break;case 4:in t poi nt4 = xs.i ndexOf(.);if (poi nt4 != -1) String s4 = xs.substri n g(0, poin t4);String z4 = xs.substri n g(po int4 + 1, xsen gth(); i nt z4_num = z4en gth();xs =;double s5 =ln teger.decode(s4)+ (double) In teger.decode(z4) / (10 * z4_nu m); sum = sum / s5; else sum = sum / In teger.decode(xs); xs =;fh = 0;break;default:break;xs = Stri n g.valueOf(sum); jtf.se