class1.java

矩阵乘法的计算程序

import java.awt.*;
import java.awt.event.*;
class Handler implements ItemListener{
	public void itemStateChanged(ItemEvent ev){
		String state="deselected";
		if (ev.getStateChange()==ItemEvent.SELECTED)
			state="selected";
		System.out.println(ev.getItem()+" "+state+" on "+ev.getItem());
	}
}
public class Class1
{
	public static void main (String[] args)
	{
		Frame f=new Frame();
		Choice color=new Choice();
		color.add("Green");
		color.add("Red");
		color.add("Blue");
		Handler handler=new Handler(); 
		//f.setLayout(new GridLayout(3,1));
		f.add(color);
		color.addItemListener(handler); 
		f.setSize(100,100);
		f.show();

	
	}
}