java jtabbedpane not firing changelistener

我有一個jtabbedpane，我試圖記錄標籤更改時。我已經使用一個變化監聽嘗試，但它似乎並沒有被解僱java jtabbedpane not firing changelistener

 import javax.swing.event.ChangeListener; 
     import javax.swing.event.ChangeEvent; 

     tabbedPane.addChangeListener(new ChangeListener() { 
      public void stateChanged(ChangeEvent e) { 
       JTabbedPane sourceTabbedPane = (JTabbedPane) e.getSource(); 
       int index = sourceTabbedPane.getSelectedIndex(); 
       System.out.println("Tab changed to: " + index); 
      } 
     });

代碼不會似乎被稱爲印刷沒有出現

來源

2017-10-20 Ceri Turner

可能重複的[JTabbedPane ChangeListener]（https://stackoverflow.com/questions/6799731/jtabbedpane-changelistener） – Colonder

那一個是要求它是否被多次解僱，礦山不是被解僱了 –