canvastest.java

来自「针对越来越多的用户喜欢JAVA」· Java 代码 · 共 35 行

import java.awt.*;
import java.awt.event.*; 
import java.util.*; 
public class CanvasTest extends Canvas implements KeyListener
{ 
  int index; 
  Color colors[] = {Color.red, Color.green, Color.blue }; 
  public void paint(Graphics g)
  { 
    g.setColor(colors[index]); 
    g.fillRect(0,0,getSize().width,getSize().height); 
  } 
  public static void main(String args[])
  { 
    Frame f = new Frame("Canvas"); 
    CanvasTest mc = new CanvasTest(); 
    f.add(mc,BorderLayout.CENTER); 
    f.setSize(150, 150); 
    mc.requestFocus(); 
    mc.addKeyListener(mc); 
    f.setVisible(true); 
  } 
  public void keyTyped(KeyEvent ev)
  { 
    index++; 
    if (index == colors.length)
    { 
      index =0; 
    } 
    repaint(); 
  } 
  public void keyPressed(KeyEvent ev) {} 
  public void keyReleased(KeyEvent ev) {} 
}