用于学习Java图形界面编程的简易计算器

package mypackage; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class Mycalculator extends WindowAdapter implements ActionListener{ /** * @param args */ JFrame frame; JTextField dataplay; JButton jia,jian,cheng,chu,tuige,fuwei,qingling,guanyu,kaifang,baifen,daoshu,dengyu,fuhao,dian; JButton num[]=new JButton[10]; JDialog dialog; double result,getResult;//用于存放计算结果和计算过程 int i=0,k=0,m,n,jisuan;//i用于对输入数据进行计数，jisuan用于保留上次的运算符号，其他控制循环 final int length=32; boolean flag,shouci=true;//flag用于防止没有输入数据而连续点击运算按钮,用于容错，shouci用于第一次运算，给getResult赋值 public void calcultor(){//设置面板和响应 frame=new JFrame("计算器"); frame.setSize(360, 230); frame.setBackground(Color.LIGHT_GRAY); frame.setLocation(380,260); frame.setLayout(new FlowLayout(FlowLayout.CENTER));//?????? frame.setResizable(false); dataplay=new JTextField(32); dataplay.setText("0"); dataplay.setHorizontalAlignment(SwingConstants.RIGHT); dataplay.setEditable(false); frame.add(dataplay); Panel toppanel=new Panel(); frame.add(toppanel); toppanel.setLayout(new GridLayout(1,4,3,3));//?????? tuige=new JButton("Back←"); tuige.setForeground(Color.RED); toppanel.add(tuige); tuige.addActionListener(this); fuwei=new JButton("CE"); fuwei.setForeground(Color.RED); toppanel.add(fuwei); fuwei.addActionListener(this); qingling=new JButton("C"); qingling.setForeground(Color.RED); toppanel.add(qingling); qingling.addActionListener(this); guanyu=new JButton("Aboutme"); guanyu.setForeground(Color.RED); toppanel.add(guanyu); guanyu.addActionListener(this); dialog=new JDialog(frame,"Mycalculator",true); dialog.setSize(230, 110); dialog.setLocation(500, 300); Label lable=new Label("欢迎交流! hello_chenjin@sina.com",1); lable.setForeground(Color.RED); dialog.add(lable,"Center"); dialog.addWindowListener(this); Panel mainpanel=new Panel(); mainpanel.setLayout(new GridLayout(1,2,8,5)); frame.add(mainpanel); Panel numpanel=new Panel(); numpanel.setLayout(new GridLayout(4,3,4,3)); mainpanel.add(numpanel); Panel calpanel=new Panel(); calpanel.setLayout(new GridLayout(4,2,4,3)); mainpanel.add(calpanel); for(m=9;m>=0;m--){ num[m]=new JButton(String.valueOf(m)); numpanel.add(num[m]); num[m].addActionListener(this); } chu=new JButton(" / "); chu.setForeground(Color.RED); calpanel.add(chu); chu.addActionListener(this); kaifang=new JButton("sqrt"); calpanel.add(kaifang); kaifang.addActionListener(this); cheng=new JButton("*"); cheng.setForeground(Color.RED); calpanel.add(cheng); cheng.addActionListener(this); baifen=new JButton("%"); calpanel.add(baifen); baifen.addActionListener(this); jian=new JButton("-"); jian.setForeground(Color.RED); calpanel.add(jian); jian.addActionListener(this); daoshu=new JButton("1/X"); calpanel.add(daoshu); daoshu.addActionListener(this); jia=new JButton("+"); jia.setForeground(Color.RED); calpanel.add(jia); jia.addActionListener(this); dengyu=new JButton("="); dengyu.setForeground(Color.RED); calpanel.add(dengyu); dengyu.addActionListener(this); fuhao=new JButton(" +/- "); numpanel.add(fuhao); fuhao.addActionListener(this); dian=new JButton("."); numpanel.add(dian); dian.addActionListener(this); Toolkit tk=Toolkit.getDefaultToolkit(); Image image=tk.createImage("jsq.gif"); frame.setIconImage(image); frame.addWindowListener(this); frame.setVisible(true); } public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub getResult=Double.valueOf(dataplay.getText()).doubleValue();//string转换为double for(k=0;k<10;k++){//数字响应，控制有效的数字输入 if(e.getSource()==num[k]){ flag=true; if(i==0) dataplay.setText(""); String s=dataplay.getText(); if(s.length()<length&&(getResult!=0||s.contains("."))) dataplay.setText(dataplay.getText()+e.getActionCommand()); if(e.getSource()==num[0]&&getResult==0&&!s.contains(".")) dataplay.setText("0"); if(e.getSource()!=num[0]&&getResult==0&&!s.contains(".")) dataplay.setText(e.getActionCommand());//?????? i++; } } if(e.getSource()==jia){ calculate();//调用计算函数 jisuan=1;}//记录此次运算符号，在下次输入运算符或等号时计算此次运算结果 if(e.getSource()==jian){ calculate(); jisuan=2; } if(e.getSource()==cheng){ calculate(); jisuan=3; } if(e.getSource()==chu){ calculate(); jisuan=4; } if(e.getSource()==dengyu){ calculate(); jisuan=0; } if(e.getSource()==fuhao){ String s=dataplay.getText(); if(s.charAt(0)=='-'){ dataplay.setText("");//重新进行赋值，去掉负号 for(i=1;i<s.length();i++){ dataplay.setText(dataplay.getText()+s.charAt(i)); } } else if(s.charAt(0)!='0'){ dataplay.setText('-'+s); } } if(e.getSource()==dian){ String s=dataplay.getText(); if(!s.contains("."))//防止出现两个点 dataplay.setText(dataplay.getText()+e.getActionCommand()); } if(e.getSource()==kaifang){ result=Math.sqrt(getResult); setResult(); } if(e.getSource()==baifen){ result=getResult/100; setResult(); } if(e.getSource()==daoshu){ result=1/getResult; setResult(); } if(e.getSource()==tuige){ String s=dataplay.getText(); if(s.length()>1){ dataplay.setText("");//重新赋值，去掉s.length()-1即最后一位 for(n=0;n<s.length()-1;n++) dataplay.setText(dataplay.getText()+s.charAt(n)); } else dataplay.setText("0"); } if(e.getSource()==fuwei||e.getSource()==qingling){ i=0;jisuan=0;flag=false;shouci=true;//初始化 dataplay.setText("0"); } if(e.getSource()==guanyu){ dialog.setVisible(true); } } public void setResult(){ dataplay.setText(String.valueOf(result)); String s=dataplay.getText(); char a=s.charAt(s.length()-1);//保留有效位 char b=s.charAt(s.length()-2); if(a=='0'&&b=='.') dataplay.setText(String.valueOf(Math.round(result))); } public void windowClosing(WindowEvent e){ if(e.getSource()==dialog)//关闭对话框 dialog.setVisible(false); else if(e.getSource()==frame)//关闭计算器 System.exit(0); } public void calculate(){//按钮按下后进行计算 if(shouci) result=getResult;//首次运算后进行赋值 else { if(jisuan==1&&flag){//计算出上次运算结果，且不是连续点击按钮，输入容错 result+=getResult; flag=false; } if(jisuan==2&&flag){ result-=getResult; flag=false; } if(jisuan==3&&flag){ result*=getResult; flag=false; } if(jisuan==4&&flag){ result/=getResult; flag=false; } } setResult(); shouci=false;i=0; } public static void main(String[] args) { // TODO Auto-generated method stub Mycalculator mycalcultor=new Mycalculator(); mycalcultor.calcultor(); } }