用java寫一個計算器
① 怎麼用java編程編寫一個計算器
打開IED：打開自己java編程的軟體，採用的是eclipse軟體。
建立java工程。
編寫類。
② 用java編寫一個小計算器(完整的)
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.text.DecimalFormat;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Calculator {
//計算器面板
private JFrame f = new JFrame("Calculator");
//輸入面扳
private JPanel inputPanel = new JPanel();
//加減乘除面板
private JPanel operationPanel = new JPanel();
//數字面板
private JPanel buttonsPanel = new JPanel();
//輸入數據文本框
private JTextField input = new JTextField(20);
//退格鍵
private JButton backspace = new JButton("BackSpace");
//清空
private JButton CE = new JButton("CE ");
//刪除
private JButton C = new JButton("C ");
//四則運算符號鍵
private JButton add = new JButton("+");
private JButton sub = new JButton("-");
private JButton mul = new JButton("*");
private JButton div = new JButton("/");
//小數點
private JButton decimal = new JButton(".");
//等號
private JButton equal = new JButton("=");
//數字鍵
private JButton zero = new JButton("0");
private JButton one = new JButton("1");
private JButton two = new JButton("2");
private JButton three = new JButton("3");
private JButton four = new JButton("4");
private JButton five = new JButton("5");
private JButton six = new JButton("6");
private JButton seven = new JButton("7");
private JButton eight = new JButton("8");
private JButton nine = new JButton("9");
private String num1 = "";//保存第一個運算數字
private String operator = "";//保存運算符號
public static void main(String[] args) {
new Calculator();//new計算器實例
}
public Calculator(){
//添加組件，布局
inputPanel.add(input);
f.add(inputPanel, BorderLayout.NORTH);
operationPanel.add(backspace);
operationPanel.add(CE);
operationPanel.add(C);
f.add(operationPanel, BorderLayout.CENTER);
buttonsPanel.add(add);
buttonsPanel.add(sub);
buttonsPanel.add(mul);
buttonsPanel.add(div);
buttonsPanel.add(one);
buttonsPanel.add(two);
buttonsPanel.add(three);
buttonsPanel.add(zero);
buttonsPanel.add(four);
buttonsPanel.add(five);
buttonsPanel.add(six);
buttonsPanel.add(decimal);
buttonsPanel.add(seven);
buttonsPanel.add(eight);
buttonsPanel.add(nine);
buttonsPanel.add(equal);
buttonsPanel.setLayout(new GridLayout(4, 4));
f.add(buttonsPanel, BorderLayout.SOUTH);
//注冊各個組件監聽事件
backspace.addMouseListener(new OperationMouseListener());
CE.addMouseListener(new OperationMouseListener());
C.addMouseListener(new OperationMouseListener());
decimal.addMouseListener(new OperationMouseListener());
equal.addMouseListener(new OperationMouseListener());
//注冊四則運算監聽
add.addMouseListener(new CalcMouseListener());
sub.addMouseListener(new CalcMouseListener());
mul.addMouseListener(new CalcMouseListener());
div.addMouseListener(new CalcMouseListener());
//注冊數字監聽事件
zero.addMouseListener(new NumberMouseListener());
one.addMouseListener(new NumberMouseListener());
two.addMouseListener(new NumberMouseListener());
three.addMouseListener(new NumberMouseListener());
four.addMouseListener(new NumberMouseListener());
five.addMouseListener(new NumberMouseListener());
six.addMouseListener(new NumberMouseListener());
seven.addMouseListener(new NumberMouseListener());
eight.addMouseListener(new NumberMouseListener());
nine.addMouseListener(new NumberMouseListener());
f.setVisible(true);
f.pack();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private class NumberMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
if(input.getText().trim().equals("0")){//如果文本框已經是0，結果還是0
input.setText(((JButton)e.getSource()).getText().trim());
}else{//否則的話，把0添加到後面，譬如文本框是1，結果就為10
input.setText(input.getText().concat(((JButton)e.getSource()).getText().trim()));
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
private class CalcMouseListener implements MouseListener{
//如果輸入的是運算符號，保存第一個結果和運算符號
public void mouseClicked(MouseEvent e) {
num1 = input.getText().trim();input.setText("");
operator = ((JButton)e.getSource()).getText().trim();
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
private class OperationMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
if(e.getSource() == backspace){//退格鍵，刪除一個直到沒有字元刪除
String inputText = input.getText();
if(inputText.length() > 0){
input.setText(inputText.substring(0, inputText.length() - 1));
}
}else if(e.getSource() == C){
input.setText("0");//C，清空所有運算數字和符號
num1 = "";
}else if(e.getSource() == CE){
input.setText("0");//CE-->將文本框置為0
}else if(e.getSource() == decimal){
String text = input.getText().trim();
//如果按了小數點，如果文本框已經有小數點，不做任何操作，否則在結果後面加上小數點
if(text.indexOf(".") == -1){
input.setText(text.concat("."));
}
}else if(e.getSource() == equal){
//如果是等號
if(!operator.trim().equals("")){
if(!input.getText().trim().equals("")){
double result = 0D;
if(operator.equals("+")){//執行加法運算
result = Double.parseDouble(num1) + Double.parseDouble(input.getText().trim());
}else if(operator.equals("-")){//減法運算
result = Double.parseDouble(num1) - Double.parseDouble(input.getText().trim());
}else if(operator.equals("*")){//乘法運算
result = Double.parseDouble(num1) * Double.parseDouble(input.getText().trim());
}else if(operator.equals("/")){//除法運算
result = Double.parseDouble(num1) / Double.parseDouble(input.getText().trim());
}
//格式化最終結果，保留兩位小數點
input.setText(new DecimalFormat("0.00").format(result));
}
}
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
}
③ 如何用java編程做一個計算器
有一個現成的參考一下吧
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() {
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");
}
}
}
④ 、使用JAVA語言編寫一個簡易的計算器
我寫了個整數可以使用的, 你可以研究一下, 添入小數部分
功能和自帶的那個一樣
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class Caculator extends JFrame {
private JLabel r1;
private JLabel r2;
private int tempResult;
boolean isResult;
private String lastOperator;
public Caculator() {
isResult = true;
tempResult = 0;
lastOperator = "+";
JPanel jp_main = new JPanel();
jp_main.setLayout(new BorderLayout());
JPanel jp_show = new JPanel();
jp_show.setBorder(new LineBorder(java.awt.Color.black));
jp_show.setLayout(new GridLayout(2, 1));
r1 = new JLabel("0", JLabel.RIGHT);
r2 = new JLabel("0", JLabel.RIGHT);
jp_show.add(r1);
jp_show.add(r2);
JPanel jp_button = new JPanel();
jp_button.setBorder(new LineBorder(java.awt.Color.black));
jp_button.setLayout(new GridLayout(4, 4));
JButton one = new JButton("1");
JButton two = new JButton("2");
JButton three = new JButton("3");
JButton four = new JButton("4");
JButton five = new JButton("5");
JButton six = new JButton("6");
JButton seven = new JButton("7");
JButton eight = new JButton("8");
JButton nine = new JButton("9");
JButton zero = new JButton("0");
JButton dot = new JButton(".");
JButton plus = new JButton("+");
JButton sub = new JButton("-");
JButton multi = new JButton("*");
JButton divide = new JButton("/");
JButton result = new JButton("=");
jp_button.add(one);
jp_button.add(two);
jp_button.add(three);
jp_button.add(sub);
jp_button.add(four);
jp_button.add(five);
jp_button.add(six);
jp_button.add(multi);
jp_button.add(seven);
jp_button.add(eight);
jp_button.add(nine);
jp_button.add(divide);
jp_button.add(zero);
jp_button.add(dot);
jp_button.add(plus);
jp_button.add(result);
JPanel reset = new JPanel();
reset.setBorder(new LineBorder(java.awt.Color.black));
JButton rb = new JButton("重置");
rb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
r1.setText("0");
r2.setText("0");
isResult = true;
tempResult = 0;
lastOperator = "+";
}
});
reset.add(rb);
jp_main.add(jp_show, BorderLayout.NORTH);
jp_main.add(jp_button, BorderLayout.CENTER);
jp_main.add(reset, BorderLayout.SOUTH);
this.add(jp_main);
one.addActionListener(new NumberButtonListener());
two.addActionListener(new NumberButtonListener());
three.addActionListener(new NumberButtonListener());
four.addActionListener(new NumberButtonListener());
five.addActionListener(new NumberButtonListener());
six.addActionListener(new NumberButtonListener());
seven.addActionListener(new NumberButtonListener());
eight.addActionListener(new NumberButtonListener());
nine.addActionListener(new NumberButtonListener());
zero.addActionListener(new NumberButtonListener());
// dot.addActionListener(new NumberButtonListener());
plus.addActionListener(new OperatorButtonListener());
sub.addActionListener(new OperatorButtonListener());
multi.addActionListener(new OperatorButtonListener());
divide.addActionListener(new OperatorButtonListener());
result.addActionListener(new ResultButtonListener());
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.setSize(370, 280);
this.setResizable(false);
this.setLocationRelativeTo(null);
}
private class NumberButtonListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
JButton jb = (JButton) arg0.getSource();
String temp = r2.getText();
if (!isResult) {
if (temp.equals("0")) {
r2.setText(jb.getText());
} else {
r2.setText(temp + jb.getText());
}
} else {
r2.setText(jb.getText());
}
isResult = false;
}
}
private class ResultButtonListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
r1.setText("0");
new OperatorButtonListener().caculate(new JButton("+"));
r2.setText(String.valueOf(tempResult));
isResult = true;
tempResult = 0;
lastOperator = "+";
}
}
private class OperatorButtonListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
JButton jb = (JButton) arg0.getSource();
String temp1 = r1.getText();
if (temp1.equals("0")) {
r1.setText(r2.getText() + " " + jb.getText());
caculate(jb);
} else {
r1.setText(temp1 + " " + r2.getText() + " " + jb.getText());
caculate(jb);
r2.setText(String.valueOf(tempResult));
}
isResult = true;
}
public void caculate(JButton jb){
if(lastOperator.equals("+")){
tempResult += Integer.valueOf(r2.getText());
}else if(lastOperator.equals("-")){
tempResult -= Integer.valueOf(r2.getText());
}else if(lastOperator.equals("*")){
tempResult *= Integer.valueOf(r2.getText());
}else if(lastOperator.equals("/")){
tempResult /= Integer.valueOf(r2.getText());
}
lastOperator = jb.getText();
}
}
}
下面是main函數
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Caculator c = new Caculator();
}
}
你運行就可以看到效果
⑤ 用JAVA編寫一個計算器
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class Jisuanqi extends JFrame implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
Result result = new Result(); // 定義text的面板
Number_Key number_key = new Number_Key(); // 定義按鈕面板
// 當點擊按鈕+、-、*、/時， = true
boolean com = false;
// 當i=0時說明是我們第一次輸入，字元串text不會累加
int i = 0;
// 存放text的內容
String text = "";
// 存放點擊按鈕+、-、*、/之前的數值
double defbutton = 0;
// +、-、*、/的代號分別為1，2，3，4
int symbol = 0;
// 構造函數
Jisuanqi() {
super("計算器"); // 設定標題
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 設定關閉窗體時退出程序
JPanel pane = new JPanel(); // 定義主面板
pane.setLayout(new BorderLayout());
setBounds(380, 220, 30, 80); // 前兩個參數是在屏幕上顯示的坐標，後兩個是大小
// 替換圖標
ImageIcon icon = new ImageIcon("F:1.GIF");
// Jisuanqi.class.getResource("APPLE.GIF")
// );
setIconImage(icon.getImage());
pane.add(result, BorderLayout.NORTH);
pane.add(number_key, BorderLayout.CENTER);
pane.add(number_key.equal, BorderLayout.SOUTH);
number_key.one.addActionListener(this); // 對1按鈕添加監聽事件
number_key.two.addActionListener(this); // 對2按鈕添加監聽事件
number_key.three.addActionListener(this); // 對3按鈕添加監聽事件
number_key.four.addActionListener(this); // 對4按鈕添加監聽事件
number_key.five.addActionListener(this); // 對5按鈕添加監聽事件
number_key.six.addActionListener(this); // 對6按鈕添加監聽事件
number_key.seven.addActionListener(this); // 對7按鈕添加監聽事件
number_key.eight.addActionListener(this); // 對8按鈕添加監聽事件
number_key.nine.addActionListener(this); // 對9按鈕添加監聽事件
number_key.zero.addActionListener(this); // 對0按鈕添加監聽事件
number_key.ce.addActionListener(this); // 對置零按鈕添加監聽事件
number_key.plus.addActionListener(this); // 對+按鈕添加監聽事件
number_key.equal.addActionListener(this); // 對=按鈕添加監聽事件
number_key.sub.addActionListener(this); // 對-按鈕添加監聽事件
number_key.mul.addActionListener(this); // 對*按鈕添加監聽事件
number_key.div.addActionListener(this); // 對/按鈕添加監聽事件
number_key.point.addActionListener(this); // 對.按鈕添加監聽事件
setContentPane(pane);
pack(); // 初始化窗體大小為正好盛放所有按鈕
}
// 各個按鈕觸發的事件
public void actionPerformed(ActionEvent e) {
/*
* 如果是點擊數字按鈕那麼先要判斷是否在此之前點擊了+、-、*、/、=，如果是那麼com=true 如果沒有com=
* false;或者是否點擊數字鍵，如果是i = 1,如果沒有 i = 0;
*/
if (e.getSource() == number_key.one) {
if (com || i == 0) {
result.text.setText("1");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "1");
}
} else if (e.getSource() == number_key.two) {
if (com || i == 0) {
result.text.setText("2");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "2");
}
} else if (e.getSource() == number_key.three) {
if (com || i == 0) {
result.text.setText("3");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "3");
}
} else if (e.getSource() == number_key.four) {
if (com || i == 0) {
result.text.setText("4");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "4");
}
} else if (e.getSource() == number_key.five) {
if (com || i == 0) {
result.text.setText("5");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "5");
}
} else if (e.getSource() == number_key.six) {
if (com || i == 0) {
result.text.setText("6");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "6");
}
} else if (e.getSource() == number_key.seven) {
if (com || i == 0) {
result.text.setText("7");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "7");
}
} else if (e.getSource() == number_key.eight) {
if (com || i == 0) {
result.text.setText("8");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "8");
}
} else if (e.getSource() == number_key.nine) {
if (com || i == 0) {
result.text.setText("9");
com = false;
i = 1;
} else {
text = result.text.getText();
result.text.setText(text + "9");
}
}
/*
* 對於0這個按鈕有一定的說法，在程序里不會出現如00000這樣的情況，加了判斷條件就是
* 如果text中的數值=0就要判斷在這個數值中是否有.存在?如果有那麼就在原來數值基礎之上添 加0;否則保持原來的數值不變
*/
else if (e.getSource() == number_key.zero) { // result.text.getText()是得到text里內容的意思
if (com || i == 0) {
result.text.setText("0");
com = false;
i = 1;
} else {
text = result.text.getText();
if (Float.parseFloat(text) > 0 || Float.parseFloat(text) < 0) { // Float.parseFloat(text)就是類型轉換了，下面都是一樣
result.text.setText(text + "0");
} else {
if (text.trim().indexOf(".") == -1) {
result.text.setText(text);
} else {
result.text.setText(text + "0");
}
}
}
} else if (e.getSource() == number_key.ce) {
result.text.setText("0");
i = 0;
com = true;
// text = "";
defbutton = 0;
}
/*
* 本程序不會讓一個數值中出現2個以上的小數點.具體做法是:判斷是否已經存在.存在就不添加, 不存在就添加.
*/
else if (e.getSource() == number_key.point) {
if (com || i == 0) {
result.text.setText("0.");
com = false;
i = 1;
} else {
text = result.text.getText();
if (text.trim().indexOf(".") == -1) {
result.text.setText(text + ".");
} else {
result.text.setText(text);
}
}
} // 獲得點擊+之前的數值
else if (e.getSource() == number_key.plus) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 1;
} // 獲得點擊-之前的數值
else if (e.getSource() == number_key.sub) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 2;
} // 獲得點擊*之前的數值
else if (e.getSource() == number_key.mul) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
System.out.println(defbutton);
symbol = 3;
} // 獲得點擊/之前的數值
else if (e.getSource() == number_key.div) {
com = true;
i = 0;
defbutton = Double.parseDouble(result.text.getText());
symbol = 4;
} else if (e.getSource() == number_key.equal) {
switch (symbol) {
case 1: { // 計算加法
double ad = defbutton
+ Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
case 2: { // 計算減法
double ad = defbutton
- Double.parseDouble(result.text.getText());
result.text.setText(String.valueOf(ad));
i = 0;
text = "";
break;
}
case 3: { // 計算乘法
double ad = defbutton
* Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
case 4: { // 計算除法
double ad = defbutton
/ Double.parseDouble(result.text.getText());
result.text.setText(ad + "");
i = 0;
text = "";
break;
}
}
System.out.println(com);
}
System.out.println(result.text.getText());
}
@SuppressWarnings("deprecation")
public static void main(String[] args) {
Jisuanqi loveyou = new Jisuanqi();
loveyou.show();
}
}
// 計算器數字按鈕定義面板
class Number_Key extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
JButton zero = new JButton("0"); // 數字鍵0
JButton one = new JButton("1"); // 數字鍵1
JButton two = new JButton("2"); // 數字鍵2
JButton three = new JButton("3"); // 數字鍵3
JButton four = new JButton("4"); // 數字鍵4
JButton five = new JButton("5"); // 數字鍵5
JButton six = new JButton("6"); // 數字鍵6
JButton seven = new JButton("7"); // 數字鍵7
JButton eight = new JButton("8"); // 數字鍵8
JButton nine = new JButton("9"); // 數字鍵9
JButton plus = new JButton("+");
JButton sub = new JButton("-");
JButton mul = new JButton("*");
JButton div = new JButton("/");
JButton equal = new JButton("=");
JButton ce = new JButton("清零"); // 置零鍵
JButton point = new JButton(".");
Number_Key() {
setLayout(new GridLayout(4, 4, 1, 1)); // 定義布局管理器為網格布局
setBackground(Color.blue); // 設置背景顏色
// 添加按鈕
add(one);
add(two);
add(three);
add(four);
add(five);
add(six);
add(seven);
add(eight);
add(nine);
add(zero);
add(plus);
add(sub);
add(mul);
add(div);
add(point);
add(equal);
add(ce);
}
}
// 計算器顯示結果的窗體
class Result extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
// text先是輸入和結果
JTextField text = new JTextField("0");
@SuppressWarnings("deprecation")
Result() { // 講輸入的數字或得到的結果在text的右邊顯示
text.setHorizontalAlignment(SwingConstants.RIGHT);
text.enable(false); // 文本框不能編輯
setLayout(new BorderLayout()); // 設定布局管理器邊框布局
add(text, BorderLayout.CENTER); // text放置在窗體的中間
}
}
⑥ 用JAVA編寫一個簡單計算器界面做出來了。
import sun.plugin.security.Broken11ClassFixer;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JFrame;
import java.awt.FlowLayout;
import javax.swing.JButton;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Scanner;
public class Test extends JFrame{
private JTextField t1;
private JTextField t2;
private JTextField t3;
private JButton b1;
public Test(){
JPanel p1=new JPanel();
JPanel p2=new JPanel();
p1.setLayout(new FlowLayout(FlowLayout.LEFT,4,3));
t1 = new JTextField("0",4);
t2 = new JTextField("0",4);
t3 = new JTextField(8);
b1 = new JButton("=");
p1.add(t1);
p1.add(new JTextField(" + "));
p1.add(t2);
p1.add(new JLabel("="));
p1.add(t3);
p2.add(b1,BorderLayout.CENTER);
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
t3.setText(Integer.toString(Integer.parseInt(t1.getText())+Integer.parseInt(t2.getText())));
}
});
add(p1,BorderLayout.NORTH);
add(p2,BorderLayout.SOUTH);
}
public static void main(String[] args){
Test frame=new Test();
frame.setTitle("計算器");
frame.setSize(300,100);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
幫你完善了下，其他來不及寫了都是一樣的，稍微改一下就行
⑦ 用Java編寫一個簡單的計算器程序
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; //數字面板
private Panel p_oper; //操作符面板
private Panel p_show; //顯示面板
private Button b_num[]; //數字按鈕
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(400, 400);
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; //存儲上一此操作符
private String strVal; //存儲數字對應的字元串
private double total; //總數
private double number; //存儲新輸入的數
private boolean firsttime; //判斷是否第一次按下的是操作符按鈕
private boolean operatorPressed;//判斷是否已經按過操作符按鈕
ButtonListener()
{
firsttime = true;
strVal = "";
}
//事件處理器
public void actionPerformed(ActionEvent e)
{
String s = ((Button)e.getSource()).getLabel().trim();
if(Character.isDigit(s.charAt(0)))
{//判斷是操作數還是操作符
handleNumber(s);
}
else
{
calculate(s);
}
}
//判斷是一元操作符還是二元操作符，並根據操作符類型做計算
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;
}
}
//判斷是否一元操作符
boolean isUnary(String s)
{
return s.equals("=")
||s.equals("cls")||s.equals("sqrt")
||s.equals("+/-")||s.equals(".");
}
//處理一元操作符
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();
}
}
//處理二元運算符
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 + "");
}
//該方法用於處理數字按鈕
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);
}
//該方法用於按下"."按鈕
void handleDecPoint()
{
operatorPressed = false;
//
if(strVal.indexOf(".")<0)
{
strVal += ".";
}
t_result.setText("");
t_result.setText(strVal);
}
//該方法用於將一個數求反
double negate(String s)
{
operatorPressed = false;
//如果是一個整數，去掉小數點後面的0
if(number == (int)number)
{
s = s.substring(0,s.indexOf("."));
}
//如果無"-"增加在該數的前面
if(s.indexOf("-")<0)
{
strVal = "-" + s;
}
else
{
strVal = s.substring(1);
}
return new Double(strVal).doubleValue();
}
//將顯示框中的值轉換成Double
double getNumberOnDisplay()
{
return new Double(t_result.getText()).doubleValue();
}
//清除屏幕並設置所有的標識
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("簡單的計算器程序");
c.setVisible(true);
}
}
⑧ 用JAVA編寫一個簡單的計算器，要求如下
太麻煩了 說個思路, 過去字元串後 先獲取+-*%的下標.然後然後分割,獲取到一個數組或list
然後循環獲取() 按照數學運算順序拼起來,
然後把公式拆分一步一步操作就得出結果啦