使用java中的MVC设置KeyListeners

我试图用Java编写自己的计算器。 我认为最好为我的代码实现MVC（模型视图控制器）设计。 我有一些基础工作，计算器确实工作，问题是我无法弄清楚我在哪里听错键的实现。 目前，我可以使用动作侦听器单击按钮并使用数值更新字段，并使用按钮进行加，减，乘，除以及清除。 所以我现在真正想到的唯一一件事是试图允许用户（我自己）选择使用键盘上的数字键盘将值附加到字段中，无论如何这里是我的代码。

这个观点

package Calculator; import java.awt.Color; import java.awt.Dimension; import java.awt.event.ActionListener; import java.awt.event.KeyListener; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextArea; public class CalcFrame extends JFrame{ private Dimension d = new Dimension(300,300); JPanel panel1 = new JPanel(); JPanel panel2 = new JPanel(); JButton equals = new JButton("="); JButton addBtn = new JButton("+"); JButton subtractBtn = new JButton("-"); JButton multiplyBtn = new JButton("*"); JButton divideBtn = new JButton("/"); JTextArea field = new JTextArea(1,20); JButton numBtn[] = new JButton[11]; String numTxt[] = {"0","1","2","3","4","5","6","7","8","9","C"}; Color newColor = new Color(10,70,40); int x = 50, y = 0; public CalcFrame(){ this.setSize(d); this.setResizable(false); // frame.setVisible(true); this.setTitle("Marks Calculator"); this.setIconImage(new ImageIcon(this.getClass().getResource("emblem.png")).getImage()); for(int i = 0; i < numBtn.length; i++){ numBtn[i] = new JButton(numTxt[i]); numBtn[i].setSize(50, 30); } for(int i = 0; i <numBtn.length; i++){ numBtn[0].setLocation(10,180); numBtn[1].setLocation(10,140); numBtn[2].setLocation(65,140); numBtn[3].setLocation(120,140); numBtn[4].setLocation(175,140); numBtn[5].setLocation(10,100); numBtn[6].setLocation(65,100); numBtn[7].setLocation(120,100); numBtn[8].setLocation(175,100); numBtn[9].setLocation(10,60); numBtn[10].setLocation(175,20); panel2.add(numBtn[i]); } field.setLocation(10, 10); field.setSize(280,30); field.setEditable(false); field.setFocusable(true); panel1.setSize(300, 50); panel1.setLayout(null); this.add(panel1); panel2.setSize(300, 250); panel2.setBackground(newColor); panel2.setLocation(0, 51); panel2.setLayout(null); this.add(panel2); equals.setLocation(230,180); equals.setSize(50, 30); panel2.add(equals); addBtn.setLocation(230, 140); addBtn.setSize(50,30); panel2.add(addBtn); subtractBtn.setLocation(230, 100); subtractBtn.setSize(50,30); panel2.add(subtractBtn); multiplyBtn.setLocation(230, 60); multiplyBtn.setSize(50,30); panel2.add(multiplyBtn); divideBtn.setLocation(230, 20); divideBtn.setSize(50,30); panel2.add(divideBtn); panel1.add(field); this.setLocationRelativeTo(rootPane); this.setLayout(null); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public void addKeyL(KeyListener keyp){ addKeyListener(keyp); } public void addListener(ActionListener listener){ addBtn.addActionListener(listener); subtractBtn.addActionListener(listener); equals.addActionListener(listener); multiplyBtn.addActionListener(listener); divideBtn.addActionListener(listener); for(int i = 0; i < numBtn.length; i++){ numBtn[i].addActionListener(listener); } } public int getFieldText(){ return Integer.parseInt(field.getText()); } public void setFieldText(){ field.setText(""); } public void setAnswer(int solution){ field.setText(Integer.toString(solution)); } } 

这是模型

 package Calculator; public class Calculations { private int total; public void addNumbers(int a, int b){ total = a + b; } public void subtractNumbers(int a, int b){ total = a - b; } public void multiplyNumbers(int a, int b){ total = a * b; } public void divideNumbers(int a, int b){ total = a / b; } public int getTotal(){ return total; } } 

这是控制器

 package Calculator; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import javax.swing.JFrame; import javax.swing.JOptionPane; public class KeyEvents{ private boolean isAdd = false; private boolean isSubtract = false; private boolean isDivide = false; private boolean isMultiply = false; private CalcFrame view = new CalcFrame(); private Calculations model = new Calculations(); int a = 0, b = 0, answer; int counter = 0; public KeyEvents(CalcFrame view, Calculations model){ this.view = view; this.model = model; this.view.addListener(new CalcListener()); this.view.addKeyL(new CalcListener()); } class CalcListener implements ActionListener, KeyListener{ @Override public void actionPerformed(ActionEvent e) { if(e.getSource().equals(view.addBtn)){ a = view.getFieldText(); view.field.setText(""); isAdd = true; isSubtract = false; isDivide = false; isMultiply = false; } if(e.getSource().equals(view.numBtn[0])){ view.field.append("0"); } if(e.getSource().equals(view.numBtn[1])){ view.field.append("1"); } if(e.getSource().equals(view.numBtn[2])){ view.field.append("2"); } if(e.getSource().equals(view.numBtn[3])){ view.field.append("3"); } if(e.getSource().equals(view.numBtn[4])){ view.field.append("4"); } if(e.getSource().equals(view.numBtn[5])){ view.field.append("5"); } if(e.getSource().equals(view.numBtn[6])){ view.field.append("6");; } if(e.getSource().equals(view.numBtn[7])){ view.field.append("7"); } if(e.getSource().equals(view.numBtn[8])){ view.field.append("8"); } if(e.getSource().equals(view.numBtn[9])){ view.field.append("9"); } if(e.getSource().equals(view.numBtn[10])){ view.field.setText(""); } if(e.getSource().equals(view.subtractBtn)){ a = view.getFieldText(); view.field.setText(""); isAdd = false; isSubtract = true; isDivide = false; isMultiply = false; } if(e.getSource().equals(view.multiplyBtn)){ a = view.getFieldText(); view.field.setText(""); isAdd = false; isSubtract = false; isDivide = false; isMultiply = true; } if(e.getSource().equals(view.divideBtn)){ a = view.getFieldText(); view.field.setText(""); isAdd = false; isSubtract = false; isDivide = true; isMultiply = false; } if(e.getSource().equals(view.equals)){ b = view.getFieldText(); if(isAdd == true){ view.setFieldText(); model.addNumbers(a, b); view.setAnswer(model.getTotal()); } if(isSubtract == true){ view.setFieldText(); model.subtractNumbers(a, b); view.setAnswer(model.getTotal()); } if(isMultiply == true){ view.setFieldText(); model.multiplyNumbers(a, b); view.setAnswer(model.getTotal()); } if(isDivide == true){ view.setFieldText(); model.divideNumbers(a, b); view.setAnswer(model.getTotal()); } } } @Override public void keyTyped(KeyEvent e) { if(e.getSource().equals(KeyEvent.VK_0)){ System.out.println("sjkdhlkj"); } if(e.getSource().equals(KeyEvent.VK_1)){ view.field.append("1"); } if(e.getSource().equals(KeyEvent.VK_2)){ view.field.append("2"); } if(e.getSource().equals(KeyEvent.VK_3)){ view.field.append("3"); } if(e.getSource().equals(KeyEvent.VK_4)){ view.field.append("4"); } if(e.getSource().equals(KeyEvent.VK_5)){ view.field.append("5"); } if(e.getSource().equals(KeyEvent.VK_6)){ view.field.append("6"); } if(e.getSource().equals(KeyEvent.VK_7)){ view.field.append("7"); } if(e.getSource().equals(KeyEvent.VK_8)){ view.field.append("8"); } if(e.getSource().equals(KeyEvent.VK_9)){ view.field.append("9"); } } @Override public void keyPressed(KeyEvent e) { if(e.getSource().equals(KeyEvent.VK_0)){ System.out.println("sjkdhlkj"); } if(e.getSource().equals(KeyEvent.VK_1)){ view.field.append("1"); } if(e.getSource().equals(KeyEvent.VK_2)){ view.field.append("2"); } if(e.getSource().equals(KeyEvent.VK_3)){ view.field.append("3"); } if(e.getSource().equals(KeyEvent.VK_4)){ view.field.append("4"); } if(e.getSource().equals(KeyEvent.VK_5)){ view.field.append("5"); } if(e.getSource().equals(KeyEvent.VK_6)){ view.field.append("6"); } if(e.getSource().equals(KeyEvent.VK_7)){ view.field.append("7"); } if(e.getSource().equals(KeyEvent.VK_8)){ view.field.append("8"); } if(e.getSource().equals(KeyEvent.VK_9)){ view.field.append("9"); } } @Override public void keyReleased(KeyEvent e) { if(e.getSource().equals(KeyEvent.VK_0)){ System.out.println("sjkdhlkj"); } if(e.getSource().equals(KeyEvent.VK_1)){ view.field.append("1"); } if(e.getSource().equals(KeyEvent.VK_2)){ view.field.append("2"); } if(e.getSource().equals(KeyEvent.VK_3)){ view.field.append("3"); } if(e.getSource().equals(KeyEvent.VK_4)){ view.field.append("4"); } if(e.getSource().equals(KeyEvent.VK_5)){ view.field.append("5"); } if(e.getSource().equals(KeyEvent.VK_6)){ view.field.append("6"); } if(e.getSource().equals(KeyEvent.VK_7)){ view.field.append("7"); } if(e.getSource().equals(KeyEvent.VK_8)){ view.field.append("8"); } if(e.getSource().equals(KeyEvent.VK_9)){ view.field.append("9"); } } } } 

tl;博士是这样的，我无法让keyListener正常工作，我已经尝试将keyListener分配给字段，panel1，panel2和this。 seperately。 一如既往地赞赏援助。

〜更新〜我决定试试GitHub，然后把我的代码放到它上面。 我希望它能让我的代码更容易理解，甚至可以分叉，这样一个人就可以搞砸了。 https://github.com/niroshido/TestCalculator/tree/master/Calculator

Answer 1

使用键绑定 。 一个简单的例子：

 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; public class CalculatorPanel extends JPanel { private JTextField display; public CalculatorPanel() { Action numberAction = new AbstractAction() { @Override public void actionPerformed(ActionEvent e) { display.setCaretPosition( display.getDocument().getLength() ); display.replaceSelection(e.getActionCommand()); } }; setLayout( new BorderLayout() ); display = new JTextField(); display.setEditable( false ); display.setHorizontalAlignment(JTextField.RIGHT); add(display, BorderLayout.NORTH); JPanel buttonPanel = new JPanel(); buttonPanel.setLayout( new GridLayout(0, 5) ); add(buttonPanel, BorderLayout.CENTER); for (int i = 0; i < 10; i++) { String text = String.valueOf(i); JButton button = new JButton( text ); button.addActionListener( numberAction ); button.setBorder( new LineBorder(Color.BLACK) ); button.setPreferredSize( new Dimension(50, 50) ); buttonPanel.add( button ); KeyStroke pressed = KeyStroke.getKeyStroke(text); InputMap inputMap = button.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW); inputMap.put(pressed, text); button.getActionMap().put(text, numberAction); } } private static void createAndShowUI() { // UIManager.put("Button.margin", new Insets(10, 10, 10, 10) ); JFrame frame = new JFrame("Calculator Panel"); frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); frame.add( new CalculatorPanel() ); frame.pack(); frame.setLocationRelativeTo( null ); frame.setVisible(true); } public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { createAndShowUI(); } }); } } 

Answer 2

您需要确保要添加KeyListener的任何组件都具有焦点，或者您应该使用键绑定。