用swing做的一个gui，可以用键盘和按钮控制一个小球上下左右移动 但是用按钮控制以后，键盘就不能再控制了

Question

代码如下import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ScollBall extends JFrame { /**
 * @param args
 */
BallPanel canvas=new BallPanel();
JPanel p2= new JPanel();
JButton left = new JButton("left");
JButton right = new JButton("right");
JButton up = new JButton("up");
JButton down = new JButton("down");

public ScollBall()
{
ButtonListener listener = new ButtonListener();
left.addActionListener(listener);
right.addActionListener(listener);
up.addActionListener(listener);
down.addActionListener(listener);

p2.add(left);
p2.add(right);
p2.add(up);
p2.add(down);

this.add(canvas,BorderLayout.CENTER);
canvas.setFocusable(true);
this.add(p2,BorderLayout.SOUTH);



}
public static void main(String[] args) {
// TODO Auto-generated method stub
ScollBall frame= new ScollBall();
frame.setSize(500, 300);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }
class ButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==left)
{
canvas.TurnLeft();

}
else if(e.getSource()==right)
{
canvas.TurnRight();

}
else if(e.getSource()==up)
{
canvas.turnup();
}
else if(e.getSource()==down)
{
canvas.TurnDown();
}

}

}
static class BallPanel extends JPanel
{
static int x=200;
static int y=100;
public BallPanel()
{
addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
switch(e.getKeyCode())
{
case KeyEvent.VK_UP:
turnup();
break;
case KeyEvent.VK_DOWN:
TurnDown();
break;
case KeyEvent.VK_LEFT:
TurnLeft();
break;
case KeyEvent.VK_RIGHT:
TurnRight();

}


}

});
}


public void TurnLeft()
{
x=x-5;
repaint();

}
public void TurnRight()
{
x=x+5;
repaint();
}
public void turnup()
{
y=y-5;
repaint();
}
public void TurnDown()
{
y=y+5;
repaint();
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawOval(x, y, 30, 30);




}
}
}

Answer 1

改变思路，给jbutton绑定加速键。

Answer 2

总体的错误我先跟你说下：
你点canvas的时候事件有在监听，但是点击button后。光标已经回不到canvas哪里了，所以事件监听会失败。具体的解决方案还想不出来。你自己先思考下把canvas改成其他的看可不可以成功。

Answer 3

说到点在上去了 .............大神！！膜拜您说的把canvas改成其他的什么呢？  谢谢了

Answer 4

啥也不说了，眼泪哗哗的
贴代码：
package a;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ScollBall extends JFrame { /**
 * @param args
 */
BallPanel canvas=new BallPanel();
JPanel p2= new JPanel();
JButton left = new JButton("left");
JButton right = new JButton("right");
JButton up = new JButton("up");
JButton down = new JButton("down");

public ScollBall()
{
ButtonListener listener = new ButtonListener();
left.addActionListener(listener);
right.addActionListener(listener);
up.addActionListener(listener);
down.addActionListener(listener);

p2.add(left);
p2.add(right);
p2.add(up);
p2.add(down);

this.add(canvas,BorderLayout.CENTER);
canvas.setFocusable(true);
this.add(p2,BorderLayout.SOUTH);



}
public static void main(String[] args) {
// TODO Auto-generated method stub
ScollBall frame= new ScollBall();
frame.setSize(500, 300);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }
class ButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==left)
{
canvas.TurnLeft();
remove(p2);
add(p2);

}
else if(e.getSource()==right)
{
canvas.TurnRight();
remove(p2);
add(p2);

}
else if(e.getSource()==up)
{
canvas.turnup();
remove(p2);
add(p2);
}
else if(e.getSource()==down)
{
canvas.TurnDown();
remove(p2);
add(p2);
}

}

}
static class BallPanel extends JPanel
{
static int x=200;
static int y=100;
public BallPanel()
{
addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
switch(e.getKeyCode())
{
case KeyEvent.VK_UP:
turnup();
break;
case KeyEvent.VK_DOWN:
TurnDown();
break;
case KeyEvent.VK_LEFT:
TurnLeft();
break;
case KeyEvent.VK_RIGHT:
TurnRight();

}


}

});
}


public void TurnLeft()
{
x=x-5;
repaint();

}
public void TurnRight()
{
x=x+5;
repaint();
}
public void turnup()
{
y=y-5;
repaint();
}
public void TurnDown()
{
y=y+5;
repaint();
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawOval(x, y, 30, 30);




}
}
}
代码基本没改就在按钮监听那边多加了两行：
if(e.getSource()==left)
{
canvas.TurnLeft();
remove(p2);
add(p2);

}

Answer 5

焦点不在canvas上了，要不按钮事件最后给canvas还回去？另外可不可以把listener加在frame上

Answer 6

哥们 你学的真好啊  向你学习了 [/quot]能解释一下那两行代码吗？