一个简单问题！！！

[applezh]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ButtonTest
{
public static void main(String[] args)
{
ButtonFrame frame = new ButtonFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
}
}

/**
A frame with a button panel
*/
class ButtonFrame extends JFrame
{
public ButtonFrame()
{
setTitle("ButtonTest");
setSize(WIDTH, HEIGHT);

// add panel to frame

ButtonPanel panel = new ButtonPanel();
Container contentPane = getContentPane();
contentPane.add(panel);
}

public static final int WIDTH = 300;
public static final int HEIGHT = 200;
}

/**
A panel with three buttons.
*/
class ButtonPanel extends JPanel
{
public ButtonPanel()
{
// create buttons

JButton yellowButton = new JButton("Yellow");
JButton blueButton = new JButton("Blue");
JButton redButton = new JButton("Red");

// add buttons to panel

add(yellowButton);
add(blueButton);
add(redButton);

// create button actions

ColorAction yellowAction = new ColorAction(Color.yellow);
ColorAction blueAction = new ColorAction(Color.blue);
ColorAction redAction = new ColorAction(Color.red);

// associate actions with buttons

yellowButton.addActionListener(yellowAction);
blueButton.addActionListener(blueAction);
redButton.addActionListener(redAction);
}

/**
An action listener that sets the panel's background color.
*/
private class ColorAction implements ActionListener
{
public ColorAction(Color c)
{
backgroundColor = c;
}

public void actionPerformed(ActionEvent event)
{
setBackground(backgroundColor);
repaint();
}

private Color backgroundColor;
}
}

上面的这段程序中的ColorAction类是内部类
如果我想把ColorAction类改成外部类 这段程序该怎么改写？？？

[maqinglong_2000]

放到外面就可以了

[applezh]

那下面这段程序那？？？他的内部类引用了外部类的方法！！！
这该怎么办？？？

import java.awt.*;
import java.awt.geom.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;

public class Sketch
{
public static void main(String[] args)
{
SketchFrame frame = new SketchFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
}
}

/**
A frame with a panel for sketching a figure
*/
class SketchFrame extends JFrame
{
public SketchFrame()
{
setTitle("Sketch");
setSize(WIDTH, HEIGHT);

// add panel to frame

SketchPanel panel = new SketchPanel();
Container contentPane = getContentPane();
contentPane.add(panel);
}

public static final int WIDTH = 300;
public static final int HEIGHT = 200;
}

/**
A panel for sketching with the keyboard.
*/
class SketchPanel extends JPanel
{
public SketchPanel()
{
last = new Point2D.Double(100, 100);
lines = new ArrayList();
KeyHandler listener = new KeyHandler();
addKeyListener(listener);
}

public boolean isFocusTraversable()
{
return true; // allow panel to get input focus
}

/**
Add a new line segment to the sketch.
@param dx the movement in x direction
@param dy the movement in y direction
*/
public void add(int dx, int dy)
{
// compute new end point
Point2D end = new Point2D.Double(last.getX() + dx,
last.getY() + dy);

// add line segment
Line2D line = new Line2D.Double(last, end);
lines.add(line);
repaint();

// remember new end point
last = end;
}

public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;

// draw all lines
for (int i = 0; i < lines.size(); i++)
g2.draw((Line2D)lines.get(i));
}

private Point2D last;
private ArrayList lines;

private static final int SMALL_INCREMENT = 1;
private static final int LARGE_INCREMENT = 5;

private class KeyHandler implements KeyListener
{
public void keyPressed(KeyEvent event)
{
int keyCode = event.getKeyCode();

// set distance
int d;
if (event.isShiftDown())
d = LARGE_INCREMENT;
else
d = SMALL_INCREMENT;

// add line segment
if (keyCode == KeyEvent.VK_LEFT) add(-d, 0);
else if (keyCode == KeyEvent.VK_RIGHT) add(d, 0);
else if (keyCode == KeyEvent.VK_UP) add(0, -d);
else if (keyCode == KeyEvent.VK_DOWN) add(0, d);
}

public void keyReleased(KeyEvent event) {}

public void keyTyped(KeyEvent event)
{
char keyChar = event.getKeyChar();

// set distance
int d;
if (Character.isUpperCase(keyChar))
{
d = LARGE_INCREMENT;
keyChar = Character.toLowerCase(keyChar);
}
else
d = SMALL_INCREMENT;

// add line segment
if (keyChar == 'h') add(-d, 0);
else if (keyChar == 'l') add(d, 0);
else if (keyChar == 'k') add(0, -d);
else if (keyChar == 'j') add(0, d);
}
}
}

[JavaBoyCaoJi]

up

[applezh]

HELP!!!