建立一個Spinner下拉選單

package test.swing.component;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.JTextField;
import javax.swing.SpinnerListModel;
import javax.swing.SpinnerModel;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;

public class TestJSpinner extends JFrame {

 public static void main(String[] args) {
  try{
   //設置系統預設的theme
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
      
      TestJSpinner frame = new TestJSpinner();
      frame.setVisible(true);
      
  }catch(Exception ex){
   ex.printStackTrace();
  }
 }

 public TestJSpinner(){  
  setTitle("Test JSpinner for version 1.0.1");
  //setIconImage(Toolkit.getDefaultToolkit().getImage(TestJTable.class.getResource("/deviantart_48x48.png")));
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  setBounds(100, 100, 450, 500);  //(左邊界,上邊界,宽度,長度)
  JPanel contentPane = new JPanel();
  contentPane.setBorder(new EmptyBorder(10, 10, 10, 10));  //(上,左,下,右)
  setContentPane(contentPane);
  
  //設置Layout的樣式來呈現component之間在Panel上的位置關係
  contentPane.setLayout(new BorderLayout());  
  
  JPanel jpane = new JPanel();
  
  // 加入資料到Spinner
        String[] portal = {"Google","Yahoo","PChome"};
        SpinnerModel portalSM = new SpinnerListModel(portal);
        
        JSpinner portalSP = new JSpinner(portalSM);
        
  // 設定Spinner的宽度和高度
  Dimension d1 = portalSP.getPreferredSize();      
     d1.width = 120;
     d1.height = 30;
     portalSP.setPreferredSize(d1);
     
     // 修改文字欄位的外觀  
   JSpinner.ListEditor editor = new JSpinner.ListEditor(portalSP);
   JTextField tf = editor.getTextField();  
   tf.setHorizontalAlignment(JTextField.CENTER);  
   tf.setFont(new Font("微軟正黑體", Font.PLAIN, 14));  
   portalSP.setEditor(editor);
   
   jpane.add(portalSP);
  
  contentPane.add(jpane, BorderLayout.CENTER);  
 }
}