JAVA学习笔记之二控件消息原理之源代码

JAVA学习笔记之二控件消息原理 的源代码如下

//test4.java

package Packet4;

public class Test4 {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
UIDemo d;
d = new UIDemo();
d.show();
}

}

//UIDemo.java

package Packet4;
import java.awt.*;
import java.awt.event.*;
public class UIDemo {
Frame f;
Button b1, b2, b3;
Label lb;
Panel pn;
List ls;
void init()
{
f = new Frame("Hello");
f.setSize(200, 200);
pn = new Panel(new FlowLayout());
// pn.setLayout(LayoutManager);
b1 = new Button("Button 1");
b2 = new Button("Button 2");
b3 = new Button("Button 3");
lb = new Label("Please click the button");
ls = new List();
b1.addActionListener(new Buttaction());
b2.addActionListener(new Buttaction());
b3.addActionListener(new Buttaction());
for(int i = 0; i< 10; i++)
{
ls.add("Item " + i);
}
ls.addActionListener(new Listactions());
pn.add(b1);
pn.add(b2);
pn.add(b3);
pn.add(lb);
pn.add(ls);
f.add(pn);
f.show();
}
class Buttaction implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
Button bb = (Button)e.getSource();
lb.setText(bb.getLabel());
}
}
class Listactions implements ItemListener, ActionListener
{
public void itemStateChanged(ItemEvent e)//单击
{
int i = 0;
i++;
}
public void actionPerformed(ActionEvent e)
{
int i = 0;
i++;
}
}

void show()
{
init();
}
}