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使用Java实现的简单的计算器
package calculate;/** * @author Wayne; * @time 2014年7月14日; * @project java计算器2.0; */import java.awt.*;import java.awt.event.*;import java.text.DecimalFormat;import javax.swing.*;import javax.swing.JOptionPane;import javax.script.*;public class Calcul extends JFrame implements ActionListener,KeyListener{ private static final long serialVersionUID = 6256855493544342895L; //一些全局初始化 JPanel buttonPanel = new JPanel(new GridLayout(5,4,3,3));//定义5*4网格，横向竖向间距为3px JTextField dataspace = new JTextField("");//显示输入的文本 JTextField message = new JTextField("就绪");//标题用户显示提示信息 String str[] = {"清除(C)","←","（","）","7","8","9","÷","4","5","6","×","1","2","3","-",".","0","等于(R)","+"};//按钮文字 private JButton btn[] = new JButton[str.length];//新建按钮 //字体和颜色 Font font = new Font("微软雅黑",Font.BOLD,22);//字体初始化 Color wordcolor = new Color(255,255,255);//字体设置为白色 Color textboxcolor = new Color(124,97,76);//消息框颜色为灰色 Color textboxcolor1 = new Color(125,125,125);//文本框颜色为灰色 public Calcul() { //一些初始化 setTitle("计算器"); setSize(WIDTH,HEIGHT); setResizable(false); setIconImage(Toolkit.getDefaultToolkit().getImage("icon.png")); //增加按钮并设置监听颜色等 for(int i = 0;i<str.length;i++) { btn[i] = new JButton(str[i]); btn[i].setFont(font); btn[i].addActionListener(this); btn[i].addKeyListener(this); // if((i>3 && i<7 ) || (i>7 && i<11) || ( i>11 && i<15) || i == 17) btn[i].setBackground(new Color(104,152,104)); //else // btn[i].setBackground(new Color(99,154,157)); btn[i].setForeground(wordcolor); buttonPanel.add(btn[i]); } btn[0].setBackground(new Color(204,88,56)); btn[7].setBackground(new Color(67,160,193)); btn[11].setBackground(new Color(67,160,193)); btn[15].setBackground(new Color(67,160,193)); btn[19].setBackground(new Color(67,160,193)); message.addKeyListener(this); //增加文本面板 JPanel textPanel = new JPanel(new GridLayout(2,1)); //将文本框加入到文本面板中 //提示框 message.setFont(font); message.setPreferredSize(new Dimension(30,50)); message.setBackground(textboxcolor); message.setForeground(wordcolor); message.setEditable(false); textPanel.add(message); //缓冲区 dataspace.setFont(font); dataspace.setPreferredSize(new Dimension(30,60)); dataspace.setBackground(textboxcolor1); dataspace.setForeground(wordcolor); dataspace.setEditable(false); textPanel.add(dataspace); //将组件加入到容器中 Container contentPane = getContentPane(); contentPane.add(buttonPanel,BorderLayout.CENTER); contentPane.add(textPanel,BorderLayout.NORTH); } public static final int WIDTH = 500; public static final int HEIGHT = 500; public static void main(String[] args) { Calcul frame = new Calcul(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Dimension dim = Toolkit.getDefaultToolkit().getScreenSize(); frame.setLocation((dim.width - 350)/2,(dim.height - 500)/2); frame.setVisible(true); } //判断输入是否为+-*/.的函数 public boolean NotSymbol(String str) { char strc = str.charAt(0); if(strc == ‘*‘ || strc == ‘/‘ || strc == ‘+‘ || strc == ‘-‘ || strc == ‘.‘) { return false; } else { return true; } } //判断前一个是否为+-*/.的函数 public boolean PreNotSym(String str) { String pre = str.substring(str.length()-1, str.length()); if(NotSymbol(pre)) return true; else return false; } //追加函数 public String addnum(String add) { String addbefore=dataspace.getText().trim(); String addafter = null; message.setText("输入的为："); if(addbefore.length() == 0 ) { if(NotSymbol(add)) addafter=addbefore+add; else if( !NotSymbol(add)) addafter = addbefore; } else if(addbefore.length() >= 2 ) { if(PreNotSym(addbefore)) { addafter=addbefore+add; } else { if(NotSymbol(add)) addafter = addbefore + add; else if( !NotSymbol(add)) addafter = addbefore; } } else if(addbefore.length() == 1) { addafter = addbefore + add; } return addafter; } @Override public void actionPerformed(ActionEvent e) { //清空 if (e.getSource() == btn[0] ) { message.setText("就绪"); dataspace.setText(""); } //退格 else if (e.getSource() == btn[1]) { message.setText("就绪"); String data = dataspace.getText().trim(); if(data.length()>0) { if(data.charAt(0) != ‘-‘) { if(data.length() >1) { if(data.charAt(data.length() - 2) == ‘.‘) { data = data.substring(0,data.length() -1); dataspace.setText(data); } data = data.substring(0,data.length() - 1); dataspace.setText(data); } else if(data.length() == 1) { dataspace.setText(""); } } else if(data.charAt(0) == ‘-‘) { if(data.length() >2) { if(data.charAt(data.length() - 2) == ‘.‘) { data = data.substring(0,data.length() -1); dataspace.setText(data); } data = data.substring(0,data.length() - 1); dataspace.setText(data); } else if(data.length() == 2) { dataspace.setText("0"); } } else if(data =http://www.mamicode.com/="0") { dataspace.setText(""); } } else {} } //左括号 else if(e.getSource() == btn[2]) { String key = "("; dataspace.setText(addnum(key)); } //右括号 else if(e.getSource() == btn[3]) { String key = ")"; dataspace.setText(addnum(key)); } //等号 else if(e.getSource() == btn[18]) { message.setText("计算得到的结果为："); ScriptEngineManager sem = new ScriptEngineManager(); ScriptEngine se = sem.getEngineByName("js"); try { int leng = dataspace.getText().length(); if(leng==0) { message.setText("你好像没输入数据哦~！"); } else { DecimalFormat df = new DecimalFormat("#.##"); //设置数据格式 Object result = se.eval(dataspace.getText()); double value =http://www.mamicode.com/ Double.parseDouble(df.format(result)); String valuestr = String.valueOf(value); dataspace.setText(valuestr); } } catch (ScriptException evt) { message.setText("表达式似乎有错呢!请重新编辑"); } catch(NumberFormatException evt) { message.setText("除数不能为0哦,请重新编辑"); } } //加点 else if(e.getSource() == btn[16]) { String key = "."; dataspace.setText(addnum(key)); } //加号 else if(e.getSource() == btn[19]) { String key = "+"; dataspace.setText(addnum(key)); } //减号 else if(e.getSource() == btn[15]) { String key = "-"; dataspace.setText(addnum(key)); } //乘号 else if(e.getSource() == btn[11]) { String key = "*"; dataspace.setText(addnum(key)); } //除号 else if(e.getSource() == btn[7]) { String key = "/"; dataspace.setText(addnum(key)); } //数字7 else if(e.getSource() == btn[4]) { String key = "7"; dataspace.setText(addnum(key)); } //数字8 else if(e.getSource() == btn[5]) { String key = "8"; dataspace.setText(addnum(key)); } //数字9 else if(e.getSource() == btn[6]) { String key = "9"; dataspace.setText(addnum(key)); } //数字4 else if(e.getSource() == btn[8]) { String key = "4"; dataspace.setText(addnum(key)); } //数字5 else if(e.getSource() == btn[9]) { String key = "5"; dataspace.setText(addnum(key)); } //数字6 else if(e.getSource() == btn[10]) { String key = "6"; dataspace.setText(addnum(key)); } //数字1 else if(e.getSource() == btn[12]) { String key = "1"; dataspace.setText(addnum(key)); } //数字2 else if(e.getSource() == btn[13]) { String key = "2"; dataspace.setText(addnum(key)); } //数字3 else if(e.getSource() == btn[14]) { String key = "3"; dataspace.setText(addnum(key)); } //数字0 else if(e.getSource() == btn[17]) { String key = "0"; dataspace.setText(addnum(key)); } } @Override public void keyTyped(KeyEvent e) { // TODO 自动生成的方法存根 } @Override //按下按钮 public void keyReleased(KeyEvent e) { int keycode = e.getKeyCode(); //退出 if(keycode == 81) { int i = JOptionPane.showConfirmDialog(null, "是否退出？","提示:", JOptionPane.YES_NO_OPTION); if(i == JOptionPane.OK_OPTION) { System.exit(0); } else{ } } //清空 if (keycode == 67 ) { message.setText("就绪"); dataspace.setText(""); } //点 else if(keycode == 110) { String key = "."; dataspace.setText(addnum(key)); } //加号 else if(keycode == 107) { String key = "+"; dataspace.setText(addnum(key)); } //减号 else if(keycode == 109) { String key = "-"; dataspace.setText(addnum(key)); } //乘号 else if(keycode == 106) { String key = "*"; dataspace.setText(addnum(key)); } //除号 else if(keycode == 111) { String key = "/"; dataspace.setText(addnum(key)); } //数字7 else if(keycode == 103 || keycode == 55) { String key = "7"; dataspace.setText(addnum(key)); } //数字8 else if(keycode == 104 || keycode == 56) { String key = "8"; dataspace.setText(addnum(key)); } //数字9 else if(keycode == 105 || (keycode == 57 && !e.isShiftDown())) { String key = "9"; dataspace.setText(addnum(key)); } //数字4 else if(keycode == 100 || keycode == 52) { String key = "4"; dataspace.setText(addnum(key)); } //数字5 else if(keycode == 101 || keycode == 53) { String key = "5"; dataspace.setText(addnum(key)); } //数字6 else if(keycode == 102 || keycode == 54) { String key = "6"; dataspace.setText(addnum(key)); } //数字1 else if(keycode == 97 || keycode == 49) { String key = "1"; dataspace.setText(addnum(key)); } //数字2 else if(keycode == 98 || keycode == 50) { String key = "2"; dataspace.setText(addnum(key)); } //数字3 else if(keycode == 99 || keycode == 51) { String key = "3"; dataspace.setText(addnum(key)); } //数字0 else if(keycode == 96 || (keycode == 48 && !e.isShiftDown())) { String key = "0"; dataspace.setText(addnum(key)); } //按下R else if(keycode == 82) { message.setText("计算得到的结果为："); ScriptEngineManager sem = new ScriptEngineManager(); ScriptEngine se = sem.getEngineByName("js"); try { int leng = dataspace.getText().length(); if(leng==0) { message.setText("你好像没输入数据哦!"); } else { DecimalFormat df = new DecimalFormat("#.##"); //设置数据格式 Object result = se.eval(dataspace.getText()); double value =http://www.mamicode.com/ Double.parseDouble(df.format(result)); String valuestr = String.valueOf(value); dataspace.setText(valuestr); } } catch (ScriptException evt) { message.setText("表达式似乎有错呢!请重新编辑"); } catch(NumberFormatException evt) { message.setText("除数不能为0哦,请重新编辑"); } } //按下Backspace else if (keycode == 8) { message.setText("就绪"); String data = dataspace.getText().trim(); if(data.length()>0) { if(data.charAt(0) != ‘-‘) { if(data.length() >1) { if(data.charAt(data.length() - 2) == ‘.‘) { data = data.substring(0,data.length() -1); dataspace.setText(data); } data = data.substring(0,data.length() - 1); dataspace.setText(data); } else if(data.length() == 1) { dataspace.setText(""); } } else if(data.charAt(0) == ‘-‘) { if(data.length() >2) { if(data.charAt(data.length() - 2) == ‘.‘) { data = data.substring(0,data.length() -1); dataspace.setText(data); } data = data.substring(0,data.length() - 1); dataspace.setText(data); } else if(data.length() == 2) { dataspace.setText("0"); } } else if(data =http://www.mamicode.com/="0") { dataspace.setText(""); } } else {} } //左括号 else if(keycode == 57 && e.isShiftDown()) { String key = "("; dataspace.setText(addnum(key)); } //右括号 else if(keycode == 48 && e.isShiftDown()) { String key = ")"; dataspace.setText(addnum(key)); } } @Override public void keyPressed(KeyEvent e) { // TODO 自动生成的方法存根 }}
小学期自己写的一个程序，功能简单。没有bug
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