keyeventuse.java

JAVA编程思想源代码 值得一下 很难找的

package chapter11;

import java.applet.Applet;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class KeyEventUse extends Applet {
	Color c;

	Label lb = new Label("可以使用R、G、B、Y键改变背景颜色");

	TextField tf = new TextField();

	public void init() {
		setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
		add(lb);
		add(tf);
		tf.addKeyListener(new myListener());
	}

	class myListener extends KeyAdapter {
		public void keyTyped(KeyEvent e) {
		}

		public void keyPressed(KeyEvent e) {
			c = Color.WHITE;
			if (e.getKeyChar() == 'r' || e.getKeyChar() == 'R')
				c = Color.red;
			else if (e.getKeyChar() == 'g' || e.getKeyChar() == 'G')
				c = Color.green;
			else if (e.getKeyChar() == 'b' || e.getKeyChar() == 'B')
				c = Color.blue;
			else if (e.getKeyChar() == 'y' || e.getKeyChar() == 'Y')
				c = Color.yellow;
			setBackground(c);
		}

		public void keyReleased(KeyEvent e) {
		}
	}

}