Jisuanqi.rar_表达式计算器

import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Jisuanqi { static Button A[][]=new Button[4][5]; static Frame fra=new Frame("计算器"); static Label lab=new Label("0.0",Label.RIGHT); public static void main(String args[]) { fra.setResizable(false); Label my=new Label("作者：阿立"); my.setSize(260,24); my.setLocation(3,194); int i,j; for(i=0;i<4;i++) for(j=0;j<5;j++) { A[i][j]=new Button(); A[i][j].setSize(45,25); A[i][j].setLocation(j*53,62+33*i); } for(i=0;i<3;i++) for(j=0;j<3;j++) { String s = Integer.toString(j+1+i*3); A[i][j].setLabel(s); } for(i=0;i<4;i++) for(j=0;j<5;j++) A[i][j].addActionListener(new MyActLister()); A[0][3].setLabel("C"); A[0][4].setLabel("CE"); A[1][3].setLabel("+"); A[1][4].setLabel("-"); A[2][3].setLabel("*"); A[2][4].setLabel("/"); A[3][0].setLabel("0"); A[3][1].setLabel("."); A[3][2].setLabel("+-"); A[3][3].setLabel("1/x"); A[3][4].setLabel("="); fra.setLayout(null); fra.setSize(260,219); lab.setSize(255,24); lab.setLocation(3,30); lab.setBackground(Color.cyan); fra.add(lab); fra.add(my); for(i=0;i<4;i++) for(j=0;j<5;j++) fra.add(A[i][j]); fra.addWindowListener(new WindowClose()); fra.setVisible(true); } static class MyActLister implements ActionListener{ private static boolean a=true; private static String[] str=new String[2]; private static String[] str1=new String[2]; private static int t=0; public void actionPerformed(ActionEvent e) { Button but=(Button)e.getSource(); if(but==A[0][0]) Shuju("1"); else if(but==A[0][1]) Shuju("2"); else if(but==A[0][2]) Shuju("3"); else if(but==A[1][0]) Shuju("4"); else if(but==A[1][1]) Shuju("5"); else if(but==A[1][2]) Shuju("6"); else if(but==A[2][0]) Shuju("7"); else if(but==A[2][1]) Shuju("8"); else if(but==A[2][2]) Shuju("9"); else if(but==A[3][0]) { if(a) lab.setText("0"); else lab.setText(lab.getText()+"0"); } else if(but==A[0][3]) { int b=lab.getText().length()-1; lab.setText(lab.getText().substring(0,b)); } else if(but==A[0][4]) { lab.setText("0.0"); a=true; t=0; for(int p=0;p<2;p++) { str[p]=null; str[p]=null; } } else if(but==A[3][1]) { boolean c=true; if(lab.getText().charAt(0)=='0') a=false; for(int k=0;k<lab.getText().length();k++) if(lab.getText().charAt(k)=='.') c=false; if(c) lab.setText(lab.getText()+"."); } else if(but==A[3][2]) { double d; d=-Double.parseDouble(lab.getText()); lab.setText(Double.toString(d)); } else if(but==A[3][3]) { double d; d=1/Double.parseDouble(lab.getText()); lab.setText(Double.toString(d)); } else if(but==A[1][3]) { if(t==0) { str[0]=lab.getText(); lab.setText("0.0"); a=true; str1[0]=("+"); t=1; } else if(t==1) { if(str1[0].equals("+")) str[0]=Double.toString(Double.parseDouble(str[0])+Double.parseDouble(lab.getText())); else if(str1[0].equals("-")) str[0]=Double.toString(Double.parseDouble(str[0])-Double.parseDouble(lab.getText())); else if(str1[0].equals("x")) str[0]=Double.toString(Double.parseDouble(str[0])*Double.parseDouble(lab.getText())); else { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[0]=Double.toString(Double.parseDouble(str[0])/Double.parseDouble(lab.getText())); } lab.setText("0.0"); a=true; str1[0]=("+"); } else if(t==2) { if(str1[1].equals("/")) { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[1]=Double.toString(Double.parseDouble(str[1])/Double.parseDouble(lab.getText())); } else str[1]=Double.toString(Double.parseDouble(str[1])*Double.parseDouble(lab.getText())); lab.setText("0.0"); a=true; if(str1[0].equals("+")) str[0]=Double.toString(Double.parseDouble(str[0])+Double.parseDouble(str[1])); else if(str1[0].equals("-")) str[0]=Double.toString(Double.parseDouble(str[0])-Double.parseDouble(str[1])); else if(str1[0].equals("x")) str[0]=Double.toString(Double.parseDouble(str[0])*Double.parseDouble(str[1])); else { if(Double.parseDouble(str[1])==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[0]=Double.toString(Double.parseDouble(str[0])/Double.parseDouble(str[1])); } t=1; str1[0]="+"; } } else if(but==A[1][4]) { if(t==0) { str[0]=lab.getText(); lab.setText("0.0"); a=true; str1[0]=("-"); t=1; } else if(t==1) { if(str1[0].equals("+")) str[0]=Double.toString(Double.parseDouble(str[0])+Double.parseDouble(lab.getText())); else if(str1[0].equals("-")) str[0]=Double.toString(Double.parseDouble(str[0])-Double.parseDouble(lab.getText())); else if(str1[0].equals("x")) str[0]=Double.toString(Double.parseDouble(str[0])*Double.parseDouble(lab.getText())); else { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[0]=Double.toString(Double.parseDouble(str[0])/Double.parseDouble(lab.getText())); } lab.setText("0.0"); a=true; str1[0]=("-"); } else if(t==2) { if(str1[1].equals("/")) { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[1]=Double.toString(Double.parseDouble(str[1])/Double.parseDouble(lab.getText())); } else str[1]=Double.toString(Double.parseDouble(str[1])*Double.parseDouble(lab.getText())); lab.setText("0.0"); a=true; if(str1[0].equals("+")) str[0]=Double.toString(Double.parseDouble(str[0])+Double.parseDouble(str[1])); else if(str1[0].equals("-")) str[0]=Double.toString(Double.parseDouble(str[0])-Double.parseDouble(str[1])); else if(str1[0].equals("x")) str[0]=Double.toString(Double.parseDouble(str[0])*Double.parseDouble(str[1])); else { if(Double.parseDouble(str[1])==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[0]=Double.toString(Double.parseDouble(str[0])/Double.parseDouble(str[1])); } t=1; str1[0]="-"; } } else if(but==A[2][3]) { if(t==0) { str[0]=lab.getText(); lab.setText("0.0"); a=true; str1[0]=("x"); t++; } else if(t==1) { str[1]=lab.getText(); lab.setText("0.0"); a=true; str1[1]=("x"); t=2; } else if(t==2) { if(str1[1].equals("x")) str[1]=Double.toString(Double.parseDouble(str[1])*Double.parseDouble(lab.getText())); else { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[1]=Double.toString(Double.parseDouble(str[1])/Double.parseDouble(lab.getText())); } lab.setText("0.0"); a=true; str1[1]=("x"); } } else if(but==A[2][4]) { if(t==0) { str[0]=lab.getText(); lab.setText("0.0"); a=true; str1[0]=("/"); t++; } else if(t==1) { str[1]=lab.getText(); lab.setText("0.0"); a=true; str1[1]=("/"); t=2; } else if(t==2) { if(str1[1].equals("x")) str[1]=Double.toString(Double.parseDouble(str[1])*Double.parseDouble(lab.getText())); else { if(Double.parseDouble(lab.getText())==0.0) JOptionPane.showMessageDialog(null,"除数不能为0！！！请按CE后重新输入！"); else str[1]=Double.toString(Double.parseDouble(str[1])/Double.parseDouble(lab.getText())); } a=true; lab.setText("0.0"); str1[1]=("/"); } } else { if(t==1) { if(str1[0].equals("+")) str[0]=Double.toString(Double.parseDouble(str[0])+Double.parseDouble(lab.getText())); else if(str1[0].equals("-")) str[0]=Double.t