给我一个语法错误"找不到MyKeyListener"。我正在尝试添加它，以便可以将播放器类实现到网格中。到目前为止，我已经创建了播放器和迷宫，但由于此语法错误，似乎无法将播放器添加到迷宫中。谁能指出我犯了什么错误。
import java.awt.*;
import javax.swing.*;
import java.awt.event.*; // Needed for ActionListener
import javax.swing.event.*; // Needed for ActionListener
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.ActionListener;
import javax.swing.JPanel;
import javax.swing.Timer;
public class www extends JFrame
{
static Maze maze = new Maze ();
static Timer t;
//======================================================== constructor
public www ()
{
// 1... Create/initialize components
// 2... Create content pane, set layout
JPanel content = new JPanel (); // Create a content pane
content.setLayout (new BorderLayout ()); // Use BorderLayout for panel
JPanel north = new JPanel ();
north.setLayout (new FlowLayout ()); // Use FlowLayout for input area
DrawArea board = new DrawArea (500, 500);
// 3... Add the components to the input area.
content.add (north, "North"); // Input area
content.add (board, "South"); // Output area
// 4... Set this window's attributes.
setContentPane (content);
pack ();
setTitle ("MAZE");
setSize (490, 500);
setKeyListener(new MyKeylistener());
setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo (null); // Center window.
}
public static void main (String[] args)
{
www window = new www ();
window.setVisible (true);
//jf.setTitle("Tutorial");
//jf.setSize(600,400);
}
class DrawArea extends JPanel
{
public DrawArea (int width, int height)
{
this.setPreferredSize (new Dimension (width, height)); // size
}
public void paintComponent (Graphics g)
{
maze.show (g); // display current state of colony
}
}
}
class Maze
{
private int grid [][];
public Maze ()
{
int [][] maze =
{ {1,0,1,1,1,1,1,1,1,1,1,1,1},
{1,0,1,0,1,0,1,0,0,0,0,0,1},
{1,0,1,0,0,0,1,0,1,1,1,0,1},
{1,0,0,0,1,1,1,0,0,0,0,0,1},
{1,0,1,0,0,0,0,0,1,1,1,0,1},
{1,0,1,0,1,1,1,0,1,0,0,0,1},
{1,0,1,0,1,0,0,0,1,1,1,0,1},
{1,0,1,0,1,1,1,0,1,0,1,0,1},
{1,0,0,0,0,0,0,0,0,0,1,0,1},
{1,1,1,1,1,1,1,1,1,1,1,0,1}};
grid = maze;
}
public void show (Graphics g)
{
for (int row = 0 ; row < grid.length ; row++)
for (int col = 0 ; col < grid [0].length ; col++)
{
if (grid [row] [col] == 1) // life
g.setColor (Color.black);
else
g.setColor (Color.white);
g.fillRect (col * 30 + 30, row * 30 + 30, 30, 30); // draw life form
}
//g.setColor(Color.RED);
//g.fillRect(60,30,30,50);
}
class MyKeyListener extends KeyAdapter {
int x = 0, y = 0,velX = 0, velY = 0;
public void keyPressed(KeyEvent e)
{
int c = e.getKeyCode();
if(c == KeyEvent.VK_LEFT)
{
velX = -1;
velY = 0;
}
if (c == KeyEvent.VK_UP)
{
velX = 0;
velY = -1;
}
if( c==KeyEvent.VK_RIGHT)
{
velX = 1;
velY = 0;
}
if(c==KeyEvent.VK_DOWN)
{
velX = 0;
velY = 1;
}
}
public MyKeyListener ()
{
tm.start ();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(Color.RED);
g.fillRect(x,y,50,30);
}
public void actionPerformed(ActionEvent e)
{
x = x+velX;
y = y +velY;
repaint();
}
}
// public void player ()
// {
//
// Timer tm = new Timer(5,this);
// int x = 0;
// int y = 0;
// int velX = 0 ;
// int velY = 0;tm.start();
// addKeyListener(this);
// setFocusable(true);
// setFocusTraversalKeysEnabled(false);
// }
// public void actionPerformed(ActionEvent e)
// {
// x = x+velX;
// y = y +velY;
// repaint();
// }
// public void keyPressed(KeyEvent e)
// {
// int c = e.getKeyCode();
// if(c == KeyEvent.VK_LEFT)
// {
// velX = -1;
// velY = 0;
// }
// if (c == KeyEvent.VK_UP)
// {
// velX = 0;
// velY = -1;
// }
// if( c==KeyEvent.VK_RIGHT)
// {
// velX = 1;
// velY = 0;
// }
// if(c==KeyEvent.VK_DOWN)
// {
// velX = 0;
// velY = 1;
// }
// }
//
// public void keyTyped(KeyEvent e){}
//
// public void keyReleased(KeyEvent e){}
}
MyKeyListener是Maze的内部类。您可以通过 Maze.MyKeyListener 引用它。
请注意，这似乎也不是一个好主意：www类是您的UI组件，应该是定义密钥侦听器的组件，而不是Maze模型。
你已经在Maze类中编写了MyKeyListener。 通常，如果要添加一个只引用一次的新侦听器，实际上可以在setKeyListener()方法的参数中编写侦听器。
新的setKeyListener()行如下所示，
setKeyListener(new Keylistener(){
int x = 0, y = 0,velX = 0, velY = 0;
public void keyPressed(KeyEvent e)
{
int c = e.getKeyCode();
if(c == KeyEvent.VK_LEFT)
{
velX = -1;
velY = 0;
}
if (c == KeyEvent.VK_UP)
{
velX = 0;
velY = -1;
}
if( c==KeyEvent.VK_RIGHT)
{
velX = 1;
velY = 0;
}
if(c==KeyEvent.VK_DOWN)
{
velX = 0;
velY = 1;
}
}
public MyKeyListener ()
{
tm.start ();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(Color.RED);
g.fillRect(x,y,50,30);
}
public void actionPerformed(ActionEvent e)
{
x = x+velX;
y = y +velY;
repaint();
}
});
然后可以删除MyKeyListener类。
值得注意的是，你通常希望在顶级 UI 对象（如窗格）中定义密钥侦听器，在本例中为Maze模型。现在，您正在子 UI 项中设置密钥侦听器，因此如果该项失焦，它可能不会触发。