试图使用按键监听器，但形状不会移动

Question

我已添加keylistener尝试并获得形状向右移动，当我按下右箭头键时。但它不起作用。我真的不知道如何使用keylistner。有人能帮我吗。

这是代码：

package walkingman; 
import java.awt.Graphics; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import java.awt.Color; 
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener; 

public class WalkingMan extends JPanel implements KeyListener{ 
    int x = 0; 
    int y = 0; 

    @Override 
    public void paint(Graphics g){ 
     super.paint(g); 
     g.fillOval(x, y, 150, 150); 
    } 

    public static void main(String[] args) throws InterruptedException { 
     JFrame frame = new JFrame ("Walking Man"); 
     frame.setSize(1080,720); 
     frame.setVisible(true); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     WalkingMan game = new WalkingMan(); 
     frame.add(game); 

     while (true){ 
      game.repaint(); 
      game.keyPressed(e); 
     } 
    } 

    @Override 
    public void keyPressed(KeyEvent e) { 
     if (e.getKeyCode() == KeyEvent.VK_RIGHT){ 
      x++; 
     } 
     repaint(); 
    } 

    @Override 
    public void keyReleased(KeyEvent e) { 
    } 

    @Override 
    public void keyTyped(KeyEvent e) { 
    } 
} 

Answer 1

有你的代码

1. 的几个问题你永远不添加KeyListener到面板上。
2. A KeyListener对于JPanel只有在它是可重点的&也将集中。
3. 覆盖paintComponent而不是paint。
4. 在方法结束时调用setVisible。
5. 摆脱整个while循环，它只会导致问题。使用KeyBindings代替KeyListener s。

---

固定码无键绑定：

import java.awt.Graphics; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import java.awt.Color; 
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener; 

public class WalkingMan extends JPanel implements KeyListener { 
    int x = 0; 
    int y = 0; 

    @Override 
    public void paintComponent(Graphics g) { // Overide paintComponent, not paint 
     super.paintComponent(g); 
     g.fillOval(x, y, 150, 150); 
    } 

    public WalkingMan() { // Class Constructor 
     setFocusable(true); // KeyListeners only work if the component is focusable 
     addKeyListener(this); // Add the KeyListener implemented by this class to the instance 
    } 

    public void createAndShowGUI() { 
     JFrame frame = new JFrame("Walking Man"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     WalkingMan game = new WalkingMan(); 
     frame.add(game); 

     frame.setSize(1080, 720); 
     frame.setVisible(true); // Call setVisible after adding the components 

     game.requestFocusInWindow(); // Request focus for the panel 
    } 

    public static void main(String[] args) throws InterruptedException { 
     new WalkingMan().createAndShowGUI(); 
    } 

    @Override 
    public void keyPressed(KeyEvent e) { 
     if (e.getKeyCode() == KeyEvent.VK_RIGHT) { 
      x++; 
     } 
     repaint(); 
    } 

    @Override 
    public void keyReleased(KeyEvent e) { 

    } 

    @Override 
    public void keyTyped(KeyEvent e) { 

    } 

} 

Answer 2

设置框显示和删除while循环，其仍然在运行之前好了。

public static void main(String[] args) throws InterruptedException { 
     JFrame frame = new JFrame ("Walking Man"); 
     frame.setSize(1080,720); 

     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     WalkingMan game = new WalkingMan(); 
     frame.add(game); 

     frame.setVisible(true);//Call visible method here 

    } 

Answer 3

为什么不调整你的代码在这样

import javax.swing.*; 
import java.awt.*; 
import javax.swing.border.LineBorder; 
import java.awt.Color; 
import java.awt.event.KeyAdapter; 
import java.awt.event.KeyEvent; 

public class WalkingMan extends JFrame{ 
    EmilsKeyClass keyBoard = new EmilsKeyClass(); 

    public WalkingMan(){ 
     add(keyBoard,BorderLayout.CENTER); 

     keyBoard.addKeyListener(new KeyAdapter(){ 
       @Override 
       public void keyPressed(KeyEvent e){ 

        if(e.getKeyCode()== KeyEvent.VK_ENTER){ 
         x++; 
         repaint(); 
        } 
       } 
      }); 
     keyBoard.setFocusable(true); 
    } 
    public static void main(String [] args){ 
     WalkingMan frame = new WalkingMan(); 

     frame.setTitle("Walking Man"); 
     frame.setSize(1080,720); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setLocationRelativeTo(null); 
     frame.setVisible(true); 
    } 
    public class EmilsKeyClass extends JPanel{ 
     int x = 0; 
     int y = 0; 

     public EmilsKeyClass(){    
     } 

     @Override 
     public void paintComponent(Graphics g){ 
      super.paintComponent(g); 
      super.paint(g); 
      g.fillOval(x, y, 150, 150); 
      //your code 
     } 
    } 

}