GUI.rar_java gui

import java.awt.*; import java.awt.event.*; public class CalcAppDemo extends Frame{ private TextField t_result; private Panel p_main; //主面板 private Panel p_num; //数字面板 private Panel p_oper; //操作符面板 private Panel p_show; //显示面板 private Button b_num[]; //数字按钮 private Button b_oper[]; //操作符面板 public CalcAppDemo(String title){ setTitle(title); t_result = new TextField("0.0", 21); p_main = new Panel(); p_num = new Panel(); p_oper = new Panel(); p_show = new Panel(); p_main.setLayout(new BorderLayout()); p_num.setLayout(new GridLayout(4, 3, 1, 1)); p_oper.setLayout(new GridLayout(4, 2, 1, 1)); b_num = new Button[12]; for(int i=0; i<9; i++) { b_num[i] = new Button(new Integer(i+1).toString()); } b_num[9] = new Button("0"); b_num[10] = new Button("cls"); b_num[11] = new Button("."); for(int i=0; i<12; i++) { p_num.add(b_num[i]); } b_oper = new Button[8]; b_oper[0] = new Button("+"); b_oper[1] = new Button("-"); b_oper[2] = new Button("*"); b_oper[3] = new Button("/"); b_oper[4] = new Button("pow"); b_oper[5] = new Button("sqrt"); b_oper[6] = new Button("+/-"); b_oper[7] = new Button("="); for(int i=0; i<8; i++) // { p_oper.add(b_oper[i]); } t_result.setEditable(false); p_show.add(t_result, BorderLayout.NORTH); p_main.add(p_show, BorderLayout.NORTH); p_main.add(p_num, BorderLayout.WEST); p_main.add(p_oper, BorderLayout.EAST); this.add(p_main, BorderLayout.CENTER); setSize(1000, 800); //setResizable(false); pack(); this.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e) { System.exit(0); } }); ButtonListener b1 = new ButtonListener(); for(int i=0; i<12; i++) { b_num[i].addActionListener(b1); } for(int i=0; i<8; i++) { b_oper[i].addActionListener(b1); } } class ButtonListener implements ActionListener { private String lastOp; //存储上一此操作符 private String strVal; //存储数字对应的字符串 private double total; //总数 private double number; //存储新输入的数 private boolean firsttime; //判断是否第一次按下的是操作符按钮 private boolean operatorPressed;//判断是否已经按过操作符按钮 ButtonListener() { firsttime = true; strVal = ""; } //事件处理器 public void actionPerformed(ActionEvent e) { String s = ((Button)e.getSource()).getLabel().trim(); if(Character.isDigit(s.charAt(0))) {//判断是操作数还是操作符 handleNumber(s); } else { calculate(s); } } //判断是一元操作符还是二元操作符，并根据操作符类型做计算 void calculate(String op) { operatorPressed = true; if(firsttime&&! isUnary(op)) { total = getNumberOnDisplay(); firsttime = false; } if(isUnary(op)) { handleUnaryOp(op); } else if(lastOp != null) { handleBinaryOp(lastOp); } if(! isUnary(op)) { lastOp = op; } } //判断是否一元操作符 boolean isUnary(String s) { return s.equals("=") ||s.equals("cls")||s.equals("sqrt") ||s.equals("+/-")||s.equals("."); } //处理一元操作符 void handleUnaryOp(String op) { if(op.equals("+/-")) {// number = negate(getNumberOnDisplay() + ""); t_result.setText(""); t_result.setText(number + ""); return; }else if(op.equals(".")) { handleDecPoint(); return; }else if(op.equals("sqrt")) { number = Math.sqrt(getNumberOnDisplay()); t_result.setText(""); t_result.setText(number + ""); return; }else if(op.equals("=")) {// if(lastOp!= null && !isUnary(lastOp)) { handleBinaryOp(lastOp); } lastOp = null; firsttime = true; return; }else { clear(); } } //处理二元运算符 void handleBinaryOp(String op) { if(op.equals("+")) { total +=number; }else if(op.equals("-")) { total -=number; }else if(op.equals("*")) { total *=number; }else if(op.equals("/")) { try { total /=number; }catch(ArithmeticException ae){} }else if(op.equals("pow")) total = Math.pow(total, number); //t_result.setText(""); lastOp = null; // strVal = ""; number = 0; t_result.setText(total + ""); } //该方法用于处理数字按钮 void handleNumber(String s) { if(!operatorPressed) { strVal += s; }else { operatorPressed = false; strVal = s; } // number = new Double(strVal).doubleValue(); t_result.setText(""); t_result.setText(strVal); } //该方法用于按下"."按钮 void handleDecPoint() { operatorPressed = false; // if(strVal.indexOf(".")<0) { strVal += "."; } t_result.setText(""); t_result.setText(strVal); } //该方法用于将一个数求反 double negate(String s) { operatorPressed = false; //如果是一个整数，去掉小数点后面的0 if(number == (int)number) { s = s.substring(0,s.indexOf(".")); } //如果无"-"增加在该数的前面 if(s.indexOf("-")<0) { strVal = "-" + s; } else { strVal = s.substring(1); } return new Double(strVal).doubleValue(); } //将显示框中的值转换成Double double getNumberOnDisplay() { return new Double(t_result.getText()).doubleValue(); } //清除屏幕并设置所有的标识 void clear() { firsttime = true; lastOp = null; strVal = ""; total = 0; number = 0; t_result.setText("0"); } } public static void main(String[] args) { CalcAppDemo c = new CalcAppDemo("简单的计算器程序"); c.setVisible(true); } }