actionlisteneruse.java

来自「JAVA编程思想源代码 值得一下 很难找的」· Java 代码 · 共 40 行

package chapter11;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.List;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.applet.*;

public class ActionListenerUse extends Applet implements ActionListener {
	List list = new List(3, false);

	public void init() {
		list.add("RED");
		list.add("GREEN");
		list.add("BLUE");
		list.add("YELLOW");
		list.select(0);
		add(list);
		list.addActionListener(this);
	}

	public void actionPerformed(ActionEvent e) {
		Graphics g = getGraphics();
		String s = list.getSelectedItem();
		if (s == "RED")
			g.setColor(Color.red);
		else if (s == "GREEN")
			g.setColor(Color.green);
		else if (s == "BLUE")
			g.setColor(Color.blue);
		else if (s == "YELLOW")
			g.setColor(Color.yellow);
		else
			g.setColor(Color.BLACK);
		g.fillRect(50, 80, 80, 80);
	}

}