我正在使用Swing制作一个小型计算器。注意：代码不完整，无法进行计算。 ActionListener一切顺利，但KeyListener没有。 我为此目的使用了KeyAdapter。 我尝试将setfocusable（）方法添加到Text区域。但是，除了删除按钮之外，我仍然按下每个按键的消息对话框。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.io.PrintStream;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
public class Calculator{
JFrame frame;
JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16;
JPanel pane,pane1,pane2;
JSplitPane sp;
Font font1 = new Font("ALGERIAN", Font.PLAIN, 40);
Font font2 = new Font("Comic Sans MS", Font.PLAIN,20);
JTextArea txt,txt2;
double number1,number2,anumber,result;
double add, sub,mul,div;
int count=0,delete=0;
double[] allnos= new double[50];
public void run(){
frame=new JFrame("Split Pane");
frame.setSize(450,500);
frame.setLocation(600,200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setResizable(true);
//Panel designing
pane=new JPanel();
pane.setBackground(Color.darkGray);
pane.setLayout(new FlowLayout(FlowLayout.LEFT));
pane1=new JPanel();
pane1.setBackground(Color.darkGray);
sp=new JSplitPane(JSplitPane.VERTICAL_SPLIT,true,pane,pane1);
sp.setOneTouchExpandable(true);
//Console Writing to txtArea
txt=new JTextArea(2,29);
txt.setEditable(false);
txt.setFont(font2);
txt.setLineWrap(true);
txt.addKeyListener(new KeyHandler());
txt2=new JTextArea(1,29);
txt2.setEditable(false);
txt2.setFont(font2);
txt2.setLineWrap(true);
txt2.setBackground(Color.lightGray);
txt2.addKeyListener(new KeyHandler());
PrintStream out=new PrintStream(new Console(txt));
System.setOut(out);
//Adding Buttons And Listeners
b1=new JButton("1");
b1.addActionListener(new ActionHandler());
b1.setFont(font1);
b2=new JButton("2");
b2.addActionListener(new ActionHandler());
b2.setFont(font1);
b3=new JButton("3");
b3.addActionListener(new ActionHandler());
b3.setFont(font1);
b4=new JButton("4");
b4.addActionListener(new ActionHandler());
b4.setFont(font1);
b5=new JButton("5");
b5.addActionListener(new ActionHandler());
b5.setFont(font1);
b6=new JButton("6");
b6.addActionListener(new ActionHandler());
b6.setFont(font1);
b7=new JButton("7");
b7.addActionListener(new ActionHandler());
b7.setFont(font1);
b8=new JButton("8");
b8.addActionListener(new ActionHandler());
b8.setFont(font1);
b9=new JButton("9");
b9.addActionListener(new ActionHandler());
b9.setFont(font1);
b10=new JButton("*");
b10.addActionListener(new ActionHandler());
b10.setFont(font1);
b12=new JButton("0");
b12.addActionListener(new ActionHandler());
b12.setFont(font1);
b11=new JButton("/");
b11.addActionListener(new ActionHandler());
b11.setFont(font1);
b13=new JButton("+");
b13.addActionListener(new ActionHandler());
b13.setFont(font1);
b14=new JButton("-");
b14.addActionListener(new ActionHandler());
b14.setFont(font1);
b15=new JButton("=");
b15.addActionListener(new ActionHandler());
b15.setFont(font1);
b16=new JButton("DEL");
b16.addActionListener(new ActionHandler());
b16.setFont(font1);
//Adding To Panel
pane1.add(b1);
pane1.add(b2);
pane1.add(b3);
pane1.add(b4);
pane1.add(b5);
pane1.add(b6);
pane1.add(b7);
pane1.add(b8);
pane1.add(b9);
pane1.add(b10);
pane1.add(b11);
pane1.add(b12);
pane1.add(b13);
pane1.add(b14);
pane1.add(b15);
pane1.add(b16);
pane.add(txt);
pane.addKeyListener(new KeyHandler());
pane.add(txt2,BorderLayout.NORTH);
frame.add(sp);
//Set Layout to pane1
GridLayout grd=new GridLayout(4,3);
grd.setHgap(5);
grd.setVgap(5);
pane1.setLayout(grd);
}
//Adding Listeners to Buttons
class ActionHandler implements ActionListener{
public void actionPerformed(ActionEvent e) {
try{
if(e.getActionCommand().equals("1")){
txt.append(b1.getText());
txt2.append(b1.getText());
}else if(e.getActionCommand().equals("2")){
txt.append(b2.getText());
txt2.append(b2.getText());
}else if(e.getActionCommand().equals("3")){
txt.append(b3.getText());
txt2.append(b3.getText());
}else if(e.getActionCommand().equals("4")){
txt.append(b4.getText());
txt2.append(b4.getText());
}else if(e.getActionCommand().equals("5")){
txt.append(b5.getText());
txt2.append(b5.getText());
}else if(e.getActionCommand().equals("6")){
txt.append(b6.getText());
txt2.append(b6.getText());
}else if(e.getActionCommand().equals("7")){
txt.append(b7.getText());
txt2.append(b7.getText());
}else if(e.getActionCommand().equals("8")){
txt.append(b8.getText());
txt2.append(b8.getText());
}else if(e.getActionCommand().equals("9")){
txt.append(b9.getText());
txt2.append(b9.getText());
}else if(e.getActionCommand().equals("*")){
txt2.append(b10.getText());
number1=numberread();
add=0;
sub=0;
mul=1;
div=0;
txt.setText("");
}else if(e.getActionCommand().equals("/")){
txt2.append(b11.getText());
number1=numberread();
add=0;
sub=0;
mul=0;
div=1;
txt.setText("");
}else if(e.getActionCommand().equals("0")){
txt.append(b12.getText());
txt2.append(b12.getText());
}else if(e.getActionCommand().equals("+")){
number1=numberread();
count++;
allnos[count]=number1;
anumber=allnos[count]+anumber;
txt2.append(b13.getText());
add=1;
sub=0;
mul=0;
div=0;
txt.setText("");
}else if(e.getActionCommand().equals("-")){
txt2.append(b14.getText());
number1=numberread();
add=0;
sub=1;
txt.setText("");
}
if(e.getActionCommand().equals("=")){
number2=numberread();
if(add>0){
result=anumber+number2;
txt.setText(Double.toString(result));
}
if(sub>0){
result=number1-number2;
txt.setText(number1+"-"+number2+"="+Double.toString(result));
}
if(mul>0){
result=number1*number2;
txt.setText(number1+"*"+number2+"="+Double.toString(result));
}
if(div>0){
if(number2!=0){
result=number1/number2;
txt.setText(number1+"/"+number2+"="+Double.toString(result));
}else if(number2==0){
System.out.println("Can't divide from 0");
}
}
}else if(e.getActionCommand().equals("DEL")){
txt.setText("");
txt2.setText("");
count=0;
anumber=0;
}
}catch(NumberFormatException Ee){
txt.setText("Error!");
int o=JOptionPane.showConfirmDialog(frame,"Note: The Calculator is not multitasking\n"+"Click Help Button if you are getting an error.","May I Help you", JOptionPane.OK_OPTION);
if(o==JOptionPane.OK_OPTION){
txt.setText("");
txt2.setText("");
}else{
txt.setText("");
txt2.setText("");
}
}
}
}
class KeyHandler extends KeyAdapter{
public void keyPressed(KeyEvent e){
if(e.getKeyChar()==KeyEvent.VK_NUMPAD1){
txt.append(b1.getText());
txt2.append(b1.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD2){
txt.append(b2.getText());
txt2.append(b2.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD3){
txt.append(b3.getText());
txt2.append(b3.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD4){
txt.append(b4.getText());
txt2.append(b4.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD5){
txt.append(b5.getText());
txt2.append(b5.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD6){
txt.append(b6.getText());
txt2.append(b6.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD7){
txt.append(b7.getText());
txt2.append(b7.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD8){
txt.append(b8.getText());
txt2.append(b8.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD9){
txt.append(b9.getText());
txt2.append(b9.getText());
}else if(e.getKeyChar()==KeyEvent.VK_NUMPAD0){
txt.append(b12.getText());
txt2.append(b12.getText());
}else if(e.getKeyChar()==KeyEvent.VK_ASTERISK){
txt2.append(b10.getText());
number1=numberread();
add=0;
sub=0;
mul=1;
div=0;
txt.setText("");
}else if(e.getKeyChar()==KeyEvent.VK_DIVIDE){
txt2.append(b11.getText());
number1=numberread();
add=0;
sub=0;
mul=0;
div=1;
txt.setText("");
}else if(e.getKeyChar()==KeyEvent.VK_ADD){
number1=numberread();
count++;
allnos[count]=number1;
anumber=allnos[count]+anumber;
txt2.append(b13.getText());
add=1;
sub=0;
mul=0;
div=0;
txt.setText("");
}else if(e.getKeyChar()==KeyEvent.VK_SUBTRACT){
txt2.append(b14.getText());
number1=numberread();
add=0;
sub=1;
txt.setText("");
}
if(e.getKeyChar()==KeyEvent.VK_ENTER){
number2=numberread();
if(add>0){
result=anumber+number2;
txt.setText(Double.toString(result));
}
if(sub>0){
result=number1-number2;
txt.setText(number1+"-"+number2+"="+Double.toString(result));
}
if(mul>0){
result=number1*number2;
txt.setText(number1+"*"+number2+"="+Double.toString(result));
}
if(div>0){
if(number2!=0){
result=number1/number2;
txt.setText(number1+"/"+number2+"="+Double.toString(result));
}else if(number2==0){
System.out.println("Can't divide from 0");
}
}
}else if(e.getKeyChar()==KeyEvent.VK_DELETE){
txt.setText("");
txt2.setText("");
count=0;
anumber=0;
}else{
JOptionPane.showMessageDialog(frame, "Enter a Valid Key");
}
}
}
public double numberread(){
double num1;
String s=txt.getText();
num1=Integer.valueOf(s);
return num1;
}
public static void main(String[] args) {
Calculator pan=new Calculator();
pan.run();
}
}