Java程序设计“简单计算器”

Java程序设计“简单计算器”一、程序代码import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Calculator{private static JTextField tf;private static String x[]=new String[2],op;private static double result=0;private static String[] s={"0","1","2","3","4","5","6","7","8","9",".","+","-","*","/","="};private static String[] sb={"backspace","clear"};private static boolean lock;public static void clearXOp(){x[0]=new String();x[1]=new String();op=new String();lock=true;}public static void clear(){clearXOp();result=0;tf.setText("0");}public static void delete(int i){int k=x[i].length()-1;StringBuffer sbr=new StringBuffer(x[i]);sbr.deleteCharAt(k);x[i]=new String(sbr);if(x[i].equals(s[10]))x[i]=new String();}public static void cancel(){int i=1;if(op.equals(""))i=0;if(x[i].equals("")){tf.setText("0");return;}delete(i);if(!x[i].equals(""))tf.setText(x[i]);elsetf.setText("0");}public static void comput(){double a,b;if(x[0].equals(""))a=result;elsea=Double.parseDouble(x[0]);b=Double.parseDouble(x[1]);if(op.equals(s[11]))result=a+b;else if(op.equals(s[12]))result=a-b;else if(op.equals(s[13]))result=a*b;else if(op.equals(s[14]))result=a/b;elseresult=a;x[0]=new String(""+result);x[1]=new String();}public static void putResult(){comput();int k=x[0].length();if(x[0].substring(k-2,k).equals(".0")){StringBuffer str=new StringBuffer(x[0]);str.delete(k-2,k);x[0]=new String(str);}tf.setText(x[0]);}public static void getX(int i,int j){if(x[j].lastIndexOf(s[10])!=-1&&s[i].equals(s[10]))return;if(x[j].equals(s[0])&&!s[i].equals(s[10])){x[j]=new String(s[i]);}else if(x[j].equals("")&&s[i].equals(s[10]))x[j]=s[0]+s[10];elsex[j]+=s[i];tf.setText(x[j]);}public static void main(String[] args){JFrame f=new JFrame("计算器");Container c=f.getContentPane();c.setLayout(new BorderLayout());Font ft = new Font("隶书",Font.PLAIN,20);clearXOp();JPanel p1,p2;p1=new JPanel(new GridLayout(2,0));tf=new JTextField();tf.setFont(ft);tf.setHorizontalAlignment(JTextField.RIGHT);tf.setText("0");tf.setEditable(false);p1.add(tf);JButton bc[]=new JButton[sb.length];JPanel p11=new JPanel(new FlowLayout());for (int i=0;i<sb.length;i++){bc[i]=new JButton(sb[i]);bc[i].setActionCommand(sb[i]);bc[i].addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){String str=e.getActionCommand();if(lock&&str.equals(sb[0])&&!op.equals(tf.getText()))cancel();else if(str.equals(sb[1]))clear();}});p11.add(bc[i]);}p1.add(p11);JButton[] b=new JButton[s.length];for(int i=0;i<s.length;i++){b[i]=new JButton(s[i]);b[i].setActionCommand(s[i]);b[i].addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){String str=e.getActionCommand();for(int i=0;i<11;i++){if(lock){if(str.equals(s[i])){if(op.equals(""))getX(i,0);else getX(i,1);}}}for(int i=11;i<s.length-1;i++){if(lock){if(str.equals(s[i])){if(op.equals("")){op=s[i];tf.setText(op);}else if(!x[1].equals("")){if(op.equals(s[14])&&Double.parseDouble(x[1])==0)lock=false;else{comput();op=s[i];}tf.setText(op);}}}}if(lock&&str.equals(s[15])){if(x[1].equals(""))x[1]="0";if(op.equals(s[14])&&Double.parseDouble(x[1])==0)lock=false;else{putResult();clearXOp();}}}});b[i].setFont(ft);}p2=new JPanel(new GridLayout(4,4,6,6));for(int i=0;i<s.length;i++){p2.add(b[i]);}c.add(p1,BorderLayout.NORTH);c.add(p2,BorderLayout.CENTER);f.setBounds(200,200,300,330);f.setV isible(true);f.setResizable(false);f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);}}二、程序截图。