java swing 组合框问题

Question

两个组合框，改变其中一个组合框的值，另一个组合框的值也会相应改变。请问各位，在Swing中如何实现？

Answer 1

public class Demo extends JFrame implements ActionListener{

private static final long serialVersionUID = -6336187772824409988L;
private JPanel rootPanel = new JPanel();
private JComboBox box1 = new JComboBox(new String[]{"1","2","3","4"});
private JComboBox box2 = new JComboBox(new String[]{"one","two","three","four"});
public Demo(){
init();
}

public void init(){
this.setSize(300,300);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setContentPane(rootPanel);

rootPanel.add(box1);
rootPanel.add(box2);

box1.addActionListener(this);
box2.addActionListener(this);
} public void actionPerformed(ActionEvent e) {
if(e.getSource() == box1){
int selectedIndex = box1.getSelectedIndex();
if(selectedIndex > -1 && selectedIndex < box1.getItemCount()){
box2.setSelectedIndex(selectedIndex);
}
}else if(e.getSource() == box2){
int selectedIndex = box2.getSelectedIndex();
if(selectedIndex > -1 && selectedIndex < box2.getItemCount()){
box1.setSelectedIndex(selectedIndex);
}
}

}

public static void main(String[] args){
Demo d = new Demo();
d.setVisible(true);
}
}

Answer 2

这里只是简单的写死的item Object,实际的数据加载同样