❶ 用java实现一个简单的计算器。
说实在的，你写的这个计算器不怎么样。特别是布局。
我给你一个很简单的吧。你自己学习一下。。
import java.awt.*;
import java.awt.event.*;
/**
*
* @author zzj
*
*/
public class Jisuanqi extends WindowAdapter {
Panel p1 = new Panel();
Panel p2 = new Panel();
Panel p3 = new Panel();
TextField txt;
private Button[] b = new Button[17];
private String ss[] = { "7", "8", "9", "+", "4", "5", "6", "-", "1", "2",
"3", "*", "清空", "0", "=", "/", "关闭" };
static double a;
static String s, str;//定义变量 创建对像
public static void main(String args[]) {
(new Jisuanqi()).frame();
}
public void frame() {
Frame fm = new Frame("简单计算器");
for (int i = 0; i <= 16; i++) {
b[i] = new Button(ss[i]);
}
for (int i = 0; i <= 15; i++) {
p2.add(b[i]);
} //创建按钮 并添加到P2
b[16].setBackground(Color.yellow);
txt = new TextField(15);
txt.setEditable(false);
for (int i = 0; i <= 16; i++) {
b[i].addActionListener(new buttonlistener());//添加监听器
}
b[16].addActionListener(new close());
fm.addWindowListener(this);
fm.setBackground(Color.red);
p1.setLayout(new BorderLayout());
p1.add(txt, "North");
p2.setLayout(new GridLayout(4, 4));
p3.setLayout(new BorderLayout());
p3.add(b[16]);
fm.add(p1, "North");
fm.add(p2, "Center");
fm.add(p3, "South");
fm.pack();
fm.setVisible(true);//都是些窗中设置 添加相关组件和监听器
}
public void windowClosing(WindowEvent e) {
System.exit(0);//退出系统
}
class buttonlistener implements ActionListener {//编写监听器事件 通过按键得出给果
public void actionPerformed(ActionEvent e) {
Button btn = (Button) e.getSource();
if (btn.getLabel() == "=") {
jisuan();
str = String.valueOf(a);
txt.setText(str);
s = "";
} else if (btn.getLabel() == "+") {
jisuan();
txt.setText("");
s = "+";
} else if (btn.getLabel() == "-") {
jisuan();
txt.setText("");
s = "-";
} else if (btn.getLabel() == "/") {
jisuan();
txt.setText("");
s = "/";
} else if (btn.getLabel() == "*") {
jisuan();
txt.setText("");
s = "*";
} else {
txt.setText(txt.getText() + btn.getLabel());
if (btn.getLabel() == "清空")
txt.setText("");
}
}
public void jisuan() {//编写具体计算方法
if (s == "+")
a += Double.parseDouble(txt.getText());
else if (s == "-")
a -= Double.parseDouble(txt.getText());
else if (s == "*")
a *= Double.parseDouble(txt.getText());
else if (s == "/")
a /= Double.parseDouble(txt.getText());
else
a = Double.parseDouble(txt.getText());
}
}
}
class close implements ActionListener {//退出
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
❷ 用Java编写一个简单的计算器界面，并且可以实现加减乘除计算，很简单一个就可以了，还需要一个归零按
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.TextField;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
public class Calculator {
public static void main(String[] args) {
Frame f = new Frame("Calculator");
final TextField tf = new TextField();
Panel p = new Panel();
f.setLayout(new BorderLayout());
f.add(tf, BorderLayout.NORTH);
f.add(p, BorderLayout.CENTER);
p.setLayout(new GridLayout(4, 4));
Button one = new Button("1");
Button two = new Button("2");
Button three = new Button("3");
Button four = new Button("4");
Button five = new Button("5");
Button six = new Button("6");
Button seven = new Button("7");
Button eight = new Button("8");
Button nine = new Button("9");
Button zero = new Button("0");
Button add = new Button("+");
Button sub = new Button("-");
Button mul = new Button("*");
Button div = new Button("/");
Button decimal = new Button(".");
final Button equal = new Button("=");
p.add(one);
p.add(two);
p.add(three);
p.add(four);
p.add(five);
p.add(six);
p.add(seven);
p.add(eight);
p.add(nine);
p.add(zero);
p.add(add);
p.add(sub);
p.add(mul);
p.add(div);
p.add(decimal);
p.add(equal);
final String[] ary = {"", null, ""};
class NumMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
String num = ((Button)e.getSource()).getLabel().trim();
if(ary[1] == null){
ary[0] = ary[0] + "" + num;
}else{
ary[2] = ary[2] + "" + num;
}
tf.setText(tf.getText() + "" + num);
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
one.addMouseListener(new NumMouseListener());
two.addMouseListener(new NumMouseListener());
three.addMouseListener(new NumMouseListener());
four.addMouseListener(new NumMouseListener());
five.addMouseListener(new NumMouseListener());
six.addMouseListener(new NumMouseListener());
seven.addMouseListener(new NumMouseListener());
eight.addMouseListener(new NumMouseListener());
nine.addMouseListener(new NumMouseListener());
zero.addMouseListener(new NumMouseListener());
class OperatotrMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
if(e.getSource() == equal){
try {
long result = calculate(Integer.parseInt(ary[0]), Integer.parseInt(ary[2]), ary[1]);
tf.setText(String.valueOf(result));
ary[0] = tf.getText();
ary[1] = null;
ary[2] = "";
} catch (Exception e1) {
e1.printStackTrace();
}
}else{
ary[1] = ((Button) e.getSource()).getLabel();
if(ary[0].length() > 0){
ary[2] = "";
}else{
ary[0] = String.valueOf(tf.getText());
}
tf.setText("");
}
}
private long calculate(int i, int j, String operator) throws Exception {
if(operator.equals("+")){
return i + j;
}else if(operator.equals("-")){
return i - j;
}else if(operator.equals("*")){
return i * j;
}else if(operator.equals("/")){
return i / j;
}else{
throw new Exception("Invalid operator.(Only +-/* accepted");
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
add.addMouseListener(new OperatotrMouseListener());
mul.addMouseListener(new OperatotrMouseListener());
div.addMouseListener(new OperatotrMouseListener());
sub.addMouseListener(new OperatotrMouseListener());
equal.addMouseListener(new OperatotrMouseListener());
f.addWindowListener(new WindowListener(){
public void windowClosing(WindowEvent e) {
System.exit(0);
}
public void windowActivated(WindowEvent e) {}
public void windowClosed(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}
public void windowDeiconified(WindowEvent e) {}
public void windowIconified(WindowEvent e) {}
public void windowOpened(WindowEvent e) {}
});
f.setVisible(true);
f.setBounds(200, 200, 250, 250);
f.validate();
}
}
❸ 如何用java编程做一个计算器
有一个现成的参考一下吧
import java.awt.event.ActionEvent;
public class Application extends JFrame {
protected String str = "";
protected boolean isChar = true;
protected boolean isEqual = false;
protected JTextField textField;
public Application() {
Listener listerner = new Listener(this);
getContentPane().setLayout(null);
JButton button = new JButton("7");
button.addActionListener(listerner);
button.setBounds(12, 69, 43, 27);
getContentPane().add(button);
textField = new JTextField();
textField.setText("0");
textField.setEditable(false);
textField.setHorizontalAlignment(JTextField.RIGHT);
textField.setBounds(12, 22, 377, 27);
getContentPane().add(textField);
textField.setColumns(10);
JButton button_1 = new JButton("8");
button_1.addActionListener(listerner);
button_1.setBounds(103, 69, 43, 27);
getContentPane().add(button_1);
JButton button_2 = new JButton("9");
button_2.addActionListener(listerner);
button_2.setBounds(182, 69, 43, 27);
getContentPane().add(button_2);
JButton button_3 = new JButton("4");
button_3.addActionListener(listerner);
button_3.setBounds(12, 106, 43, 27);
getContentPane().add(button_3);
JButton button_4 = new JButton("5");
button_4.addActionListener(listerner);
button_4.setBounds(103, 106, 43, 27);
getContentPane().add(button_4);
JButton button_5 = new JButton("6");
button_5.addActionListener(listerner);
button_5.setBounds(182, 106, 43, 27);
getContentPane().add(button_5);
JButton button_6 = new JButton("1");
button_6.addActionListener(listerner);
button_6.setBounds(12, 143, 43, 27);
getContentPane().add(button_6);
JButton button_7 = new JButton("2");
button_7.addActionListener(listerner);
button_7.setBounds(103, 143, 43, 27);
getContentPane().add(button_7);
JButton button_8 = new JButton("3");
button_8.addActionListener(listerner);
button_8.setBounds(182, 143, 43, 27);
getContentPane().add(button_8);
JButton button_9 = new JButton("+");
button_9.addActionListener(listerner);
button_9.setBounds(269, 72, 43, 27);
getContentPane().add(button_9);
JButton button_10 = new JButton("-");
button_10.addActionListener(listerner);
button_10.setBounds(346, 72, 43, 27);
getContentPane().add(button_10);
JButton button_11 = new JButton("*");
button_11.addActionListener(listerner);
button_11.setBounds(269, 109, 43, 27);
getContentPane().add(button_11);
JButton button_12 = new JButton("/");
button_12.addActionListener(listerner);
button_12.setBounds(346, 109, 43, 27);
getContentPane().add(button_12);
JButton button_13 = new JButton("=");
button_13.addActionListener(listerner);
button_13.setBounds(346, 143, 43, 27);
getContentPane().add(button_13);
JButton button_14 = new JButton("0");
button_14.addActionListener(listerner);
button_14.setBounds(103, 180, 43, 27);
getContentPane().add(button_14);
JButton btnReset = new JButton("reset");
btnReset.addActionListener(listerner);
btnReset.setBounds(269, 180, 118, 27);
getContentPane().add(btnReset);
JButton button_15 = new JButton(".");
button_15.addActionListener(listerner);
button_15.setBounds(269, 146, 43, 27);
getContentPane().add(button_15);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
this.setSize(442, 260);
this.setLocationRelativeTo(null);
this.setVisible(true);
}
public static void main(String[] args) {
new Application();
}
}
class Listener implements ActionListener {
private Application app = null;
public Listener(Application app) {
this.app = app;
}
public void actionPerformed(ActionEvent e) {
String value = e.getActionCommand();
if (value.matches("[0-9.]")) {
if (app.isChar) {
app.textField.setText("");
app.isChar = false;
}
if (app.isEqual && app.str.matches("[0-9.]*")) {
app.str = "";
app.isEqual = false;
}
app.str += value;
app.textField.setText(app.textField.getText() + value);
} else if (value.matches("[\\+\\-\\*/]")) {
if (!app.str.substring(app.str.length() - 1)
.matches("[\\+\\-\\*/]")) {
app.str += value;
app.isChar = true;
}
} else if ("=".equals(value)) {
app.isEqual = true;
if (app.str.substring(app.str.length() - 1).matches("[\\+\\-]")) {
app.str += "0";
} else if (app.str.substring(app.str.length() - 1)
.matches("[\\*/]")) {
app.str += "1";
}
Interpreter bsh = new Interpreter();
String obj = null;
try {
obj = bsh.eval(app.str).toString();
} catch (Exception exception) {
System.out.println(exception.getMessage());
}
System.out.println(app.str);
app.textField.setText(obj);
app.str = obj;
app.isChar = true;
} else {
app.str = "";
app.textField.setText("0");
}
}
}