appletkeyadapterdemo.java

来自「JAVA编程思想源代码 值得一下 很难找的」· Java 代码 · 共 50 行

package chapter12;

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class AppletKeyAdapterDemo extends Applet {
	String str = "请按a键";

	public void init() {
		this.addKeyListener(new KeyListener());
	}

	public void start() {
	}

	public void stop() {
	}

	public void destroy() {
	}

	public void paint(Graphics g) {
		g.setColor(Color.red);
		g.drawString(str, 20, 60);
	}

	class KeyListener extends KeyAdapter {

		public void keyPressed(KeyEvent e) { //
			char key = e.getKeyChar();
			if (key == 'a') {
				str = "a键按下";
				repaint();
			}
		}

		public void keyReleased(KeyEvent e) {
			char key = e.getKeyChar();
			if (key == 'a') {
				str = "a键释放";
				repaint();
			}
		}
	}

}