通过我刚刚在工作中创建的应用程序，我的老板正在向我施加压力，要求我添加一个简单的计算器工具，以便客户“获得更多钱”。我已经创建了计算器，但我无法弄清楚如何运行计算。这是我的代码：
package Interface;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class GUI {
public static void main(String[] args) {
JPanel Panel = new JPanel();
JFrame Frame = new JFrame("Calculator");
Font ButtonFont = new Font("Font",1,30);
final JTextArea Print = new JTextArea(1,27);
Panel.add(Print);
JButton Clear = new JButton("C");
Clear.setPreferredSize(new Dimension(70,70));
Clear.setFont(ButtonFont);
Panel.add(Clear);
Clear.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Print.setText("");
}
});
JButton PosNeg = new JButton("+/-");
PosNeg.setPreferredSize(new Dimension(70,70));
PosNeg.setFont(ButtonFont);
Panel.add(PosNeg);
JButton Percent = new JButton("%");
Percent.setPreferredSize(new Dimension(70,70));
Percent.setFont(ButtonFont);
Panel.add(Percent);
JButton Divide = new JButton("/");
Divide.setPreferredSize(new Dimension(70,70));
Divide.setFont(ButtonFont);
Panel.add(Divide);
JButton Seven = new JButton("7");
Seven.setPreferredSize(new Dimension(70,70));
Seven.setFont(ButtonFont);
Panel.add(Seven);
JButton Eight = new JButton("8");
Eight.setPreferredSize(new Dimension(70,70));
Eight.setFont(ButtonFont);
Panel.add(Eight);
JButton Nine = new JButton("9");
Nine.setPreferredSize(new Dimension(70,70));
Nine.setFont(ButtonFont);
Panel.add(Nine);
JButton Multiply = new JButton("X");
Multiply.setPreferredSize(new Dimension(70,70));
Multiply.setFont(ButtonFont);
Panel.add(Multiply);
JButton Four = new JButton("4");
Four.setPreferredSize(new Dimension(70,70));
Four.setFont(ButtonFont);
Panel.add(Four);
JButton Five = new JButton("5");
Five.setPreferredSize(new Dimension(70,70));
Five.setFont(ButtonFont);
Panel.add(Five);
JButton Six = new JButton("6");
Six.setPreferredSize(new Dimension(70,70));
Six.setFont(ButtonFont);
Panel.add(Six);
JButton Subtract = new JButton("-");
Subtract.setPreferredSize(new Dimension(70,70));
Subtract.setFont(ButtonFont);
Panel.add(Subtract);
JButton One = new JButton("1");
One.setPreferredSize(new Dimension(70,70));
One.setFont(ButtonFont);
Panel.add(One);
JButton Two = new JButton("2");
Two.setPreferredSize(new Dimension(70,70));
Two.setFont(ButtonFont);
Panel.add(Two);
JButton Three = new JButton("3");
Three.setPreferredSize(new Dimension(70,70));
Three.setFont(ButtonFont);
Panel.add(Three);
JButton Add = new JButton("+");
Add.setPreferredSize(new Dimension(70,70));
Add.setFont(ButtonFont);
Panel.add(Add);
JButton Dec = new JButton(".");
Dec.setPreferredSize(new Dimension(70,70));
Dec.setFont(ButtonFont);
Panel.add(Dec);
JButton Zero = new JButton("0");
Zero.setPreferredSize(new Dimension(70,70));
Zero.setFont(ButtonFont);
Panel.add(Zero);
JButton Root = new JButton("\\/");
Root.setPreferredSize(new Dimension(70,70));
Root.setFont(ButtonFont);
Panel.add(Root);
final JButton Equal = new JButton("=");
Equal.setPreferredSize(new Dimension(70,70));
Equal.setFont(ButtonFont);
Panel.add(Equal);
Frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Frame.getContentPane().add(Panel, BorderLayout.CENTER);
Frame.pack();
Frame.setVisible(true);
Frame.setLocationRelativeTo(null);
Frame.setResizable(false);
Frame.setSize(350,450);
}
}
答案 0 :(得分：0)
首先，我建议您使用JTextField代替JTextArea。
其次，要进行简单的计算，您需要为每个按钮添加ActionListener()。然后，您可以在JTextField的操作员按钮（+ / - / * //）上将结果添加到actionListener。
请看这个示例。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Carl extends JFrame{
JTextField text1= new JTextField ();
JLabel label1= new JLabel (" ");
JButton button1= new JButton ("1");
JButton button2= new JButton ("2");
JButton button3= new JButton ("3");
JButton button4= new JButton ("4");
JButton button5= new JButton ("5");
JButton button6= new JButton ("6");
JButton button7= new JButton ("7");
JButton button8= new JButton ("8");
JButton button9= new JButton ("9");
JButton button10= new JButton ("0");
JButton button11= new JButton ("+");
JButton button12= new JButton ("-");
JButton button13= new JButton ("*");
JButton button14= new JButton ("/");
JButton button15= new JButton ("=");
JButton button16= new JButton ("C");
JLabel blank1 = new JLabel("");
JLabel blank2 = new JLabel("");
JLabel blank3 = new JLabel("");
JLabel blank4 = new JLabel("");
Font times= new Font ("Times New Roman", Font.BOLD, 14);
int operation1;
int operation2;
int operation3;
int operation4;
String n1,n2;
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
public Carl(){
setResizable(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("Calculator");
setSize(600,600);
button1.setForeground(Color.BLACK);
button2.setForeground(Color.BLACK);
button3.setForeground(Color.BLACK);
button4.setForeground(Color.BLACK);
button5.setForeground(Color.BLACK);
button6.setForeground(Color.BLACK);
button7.setForeground(Color.BLACK);
button8.setForeground(Color.BLACK);
button9.setForeground(Color.BLACK);
button10.setForeground(Color.BLACK);
button11.setForeground(Color.BLACK);
button12.setForeground(Color.BLACK);
button13.setForeground(Color.BLACK);
button14.setForeground(Color.BLACK);
button15.setForeground(Color.BLACK);
button16.setForeground(Color.BLACK);
button1.setBackground(Color.YELLOW);
button2.setBackground(Color.YELLOW);
button3.setBackground(Color.YELLOW);
button4.setBackground(Color.YELLOW);
button5.setBackground(Color.YELLOW);
button6.setBackground(Color.YELLOW);
button7.setBackground(Color.YELLOW);
button8.setBackground(Color.YELLOW);
button9.setBackground(Color.YELLOW);
button10.setBackground(Color.YELLOW);
button11.setBackground(Color.YELLOW);
button12.setBackground(Color.YELLOW);
button13.setBackground(Color.YELLOW);
button14.setBackground(Color.YELLOW);
button15.setBackground(Color.YELLOW);
button16.setBackground(Color.YELLOW);
button1.setToolTipText ("one");
button2.setToolTipText ("two");
button3.setToolTipText ("three");
button4.setToolTipText ("four");
button5.setToolTipText ("five");
button6.setToolTipText ("six");
button7.setToolTipText ("seven");
button8.setToolTipText ("eight");
button9.setToolTipText ("nine");
button10.setToolTipText ("zero");
button11.setToolTipText ("addition");
button12.setToolTipText ("subtraction");
button13.setToolTipText ("multiplication");
button14.setToolTipText ("division");
button15.setToolTipText ("equal");
button16.setToolTipText ("clear");
button1.setFont(times);
button2.setFont(times);
button3.setFont(times);
button4.setFont(times);
button5.setFont(times);
button6.setFont(times);
button7.setFont(times);
button8.setFont(times);
button9.setFont(times);
button10.setFont(times);
button11.setFont(times);
button12.setFont(times);
button13.setFont(times);
button14.setFont(times);
button15.setFont(times);
button16.setFont(times);
label1.setFont(times);
setLayout(new BorderLayout());
p1.setLayout(new GridLayout(6,3,2,2));
p1.add(p2,BorderLayout.CENTER);
p1.add(label1);
p1.add(text1);
p1.add(blank3);
p1.add(button7);
p1.add(button8);
p1.add(button9);
p1.add(button11);
p1.add(button4);
p1.add(button5);
p1.add(button6);
p1.add(button12);
p1.add(button1);
p1.add(button2);
p1.add(button3);
p1.add(button13);
p1.add(button10);
p1.add(button16);
p1.add(button15);
p1.add(button14);
add(p1,BorderLayout.CENTER);
button1.addActionListener(new Listener1());
button2.addActionListener(new Listener2());
button3.addActionListener(new Listener3());
button4.addActionListener(new Listener4());
button5.addActionListener(new Listener5());
button6.addActionListener(new Listener6());
button7.addActionListener(new Listener7());
button8.addActionListener(new Listener8());
button9.addActionListener(new Listener9());
button10.addActionListener(new Listener0());
button11.addActionListener(new ListenerAdd());
button12.addActionListener(new ListenerSub());
button13.addActionListener(new ListenerMul());
button14.addActionListener(new ListenerDiv());
button15.addActionListener(new ListenerEqual());
button16.addActionListener(new ListenerClear());
setVisible(true);
}
private class Listener1 implements ActionListener{
public void actionPerformed (ActionEvent a){
n1= text1.getText ();
text1.setText (n1+"1");
}
}
private class Listener2 implements ActionListener{
public void actionPerformed (ActionEvent b){
n1= text1.getText ();
text1.setText (n1+"2");
}
}
private class Listener3 implements ActionListener{
public void actionPerformed (ActionEvent c){
n1= text1.getText ();
text1.setText (n1+"3");
}
}
private class Listener4 implements ActionListener{
public void actionPerformed (ActionEvent d){
n1= text1.getText ();
text1.setText (n1+"4");
}
}
private class Listener5 implements ActionListener{
public void actionPerformed (ActionEvent e){
n1= text1.getText ();
text1.setText (n1+"5");
}
}
private class Listener6 implements ActionListener{
public void actionPerformed (ActionEvent f){
n1= text1.getText ();
text1.setText (n1+"6");
}
}
private class Listener7 implements ActionListener{
public void actionPerformed (ActionEvent g){
n1= text1.getText ();
text1.setText (n1+"7");
}
}
private class Listener8 implements ActionListener{
public void actionPerformed (ActionEvent h){
n1= text1.getText ();
text1.setText (n1+"8");
}
}
private class Listener9 implements ActionListener{
public void actionPerformed (ActionEvent i){
n1= text1.getText ();
text1.setText (n1+"9");
}
}
private class Listener0 implements ActionListener{
public void actionPerformed (ActionEvent j){
n1= text1.getText ();
text1.setText (n1+"0");
}
}
private class ListenerAdd implements ActionListener{
public void actionPerformed (ActionEvent k){
n2= text1.getText ();
operation1=1;
text1.setText ("");
}
}
private class ListenerSub implements ActionListener{
public void actionPerformed (ActionEvent l){
n2= text1.getText ();
operation2=2;
text1.setText ("");
}
}
private class ListenerMul implements ActionListener{
public void actionPerformed (ActionEvent m){
n2= text1.getText ();
operation3=3;
text1.setText ("");
}
}
private class ListenerDiv implements ActionListener{
public void actionPerformed (ActionEvent n){
n2= text1.getText ();
operation4=4;
text1.setText ("");
}
}
private class ListenerEqual implements ActionListener{
public void actionPerformed (ActionEvent o){
if(operation1==1){
int a=Integer.parseInt(n2);
int b=Integer.parseInt(text1.getText());
int sum = (a + b);
String sum1 = Integer.toString(sum);
text1.setText(sum1);
}
else{
text1.getText();
}
if(operation2==2){
int a=Integer.parseInt(n2);
int b=Integer.parseInt(text1.getText());
int dif = (a - b);
String dif1 = Integer.toString(dif);
text1.setText(dif1);
}
else{
text1.getText();
}
if(operation3==3){
int a=Integer.parseInt(n2);
int b=Integer.parseInt(text1.getText());
int product = (a * b);
String product1 = Integer.toString(product);
text1.setText(product1);
}
else{
text1.getText();
}
if(operation4==4){
double a=Double.parseDouble(n2);
double b=Double.parseDouble(text1.getText());
double quo = (a/b);
String quo1 = Double.toString(quo);
text1.setText(quo1);
}
else{
text1.getText();
}
}
}
private class ListenerClear implements ActionListener{
public void actionPerformed (ActionEvent p){
text1.setText("");
}
}
public static void main(String[]args){
Carl frame= new Carl();
}
}