mouseandkeydemo.java

一个GUI编程的例子 一个GUI编程的例子

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MouseAndKeyDemo extends JApplet {
protected int lastX = 0, lastY = 0;
public void init() {
setBackground(Color.white);
setForeground(Color.blue);
addMouseListener(new PositionRecorder());
addMouseMotionListener(new LineDrawer());
addKeyListener(new CharDrawer());
}
protected void record(int x, int y) {
lastX = x;
lastY = y;
}
private class PositionRecorder extends MouseAdapter {
public void mouseEntered(MouseEvent e) {
requestFocus();
record(e.getX(), e.getY());
}
public void mousePressed(MouseEvent e) {
record(e.getX(), e.getY());
}
}
private class LineDrawer extends MouseMotionAdapter {
public void mouseDragged(MouseEvent e) {
int x = e.getX();
int y = e.getY();
Graphics g = getGraphics();
g.drawLine(lastX, lastY, x, y);
record(x, y);
}
}
private class CharDrawer extends KeyAdapter {
public void keyTyped(KeyEvent event) {
String s = String.valueOf(event.getKeyChar());
getGraphics().drawString(s, lastX, lastY);
record(lastX + 11, lastY);
}
}
}