下拉列表框

public class MyImageIcon extends JFrame{ 
JComboBox jc=new JComboBox(new MyComboBox());
JLabel jl=new JLabel("请选择证件");
public MyImageIcon(){
Container c=getContentPane();//创建容器
c.setLayout(new FlowLayout());//流布局
c.add(jl);//将标签添加到容器
c.add(jc);//下拉列表框
 
setSize(350,150);
setVisible(true);

}
 


 
public static void main(String[] args) {
// TODO Auto-generated method stub
new MyImageIcon().setVisible(true);
}


}
class MyComboBox extends AbstractListModel implements ComboBoxModel{
String selecteditem=null;
String[] test={"身份证","军人证","学生证","工作证"};
public Object getElementAt(int index){//根据索引返回值
return test[index];

}
public int getSize(){//返回下拉列表框中项目的数目
return test.length;
}
public void setSelectedItem(Object item){//设置下拉列表框项目
selecteditem=(String)item;

}
public void setSelecteditem(Object item){
selecteditem=(String)item;
}
 
@Override
public Object getSelectedItem() {
// TODO Auto-generated method stub
return selecteditem;
}
}