如何從combobox值傳遞到

Question

不知何故，我設法使該ID不顯示在組合框中，但那麼當我按下按鈕時如何做到這一點，我可以得到ID值？按下按鈕時使用String from = (String) jComboBox1.getSelectedItem();不起作用。我得到String code = (String) item.getValue();我需要的id，但是如何將它傳遞給下一個查詢？

public void select() { 

     try { 
      String sql = "select * from category"; 
      pst = con.prepareStatement(sql); 
      rs = pst.executeQuery(); 

      while (rs.next()) { 

     jComboBox1.addItem(new Item<String>(rs.getString("mkid"), rs.getString("name"))); 

      } 

     } catch (Exception e) { 
      JOptionPane.showMessageDialog(null, e); 
     } 

     jComboBox1.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       JComboBox jComboBox1 = (JComboBox) e.getSource(); 
       Item item = (Item) jComboBox1.getSelectedItem(); 
       String code = (String) item.getValue(); 
       System.out.println(code); 
      } 
     }); 


    } 


    The item 

    public class Item<V> implements Comparable<Item> 
    { 
    private V value; 
    private String description; 


    public Item(V value, String description) 
    { 
     this.value = value; 
     this.description = description; 
    } 


    public V getValue() 
    { 
     return value; 
    } 

    public String getDescription() 
    { 
     return description; 
    } 

    public int compareTo(Item item) 
    { 
     return getDescription().compareTo(item.getDescription()); 
    } 

    @Override 
    public boolean equals(Object object) 
    { 
     Item item = (Item)object; 
     return value.equals(item.getValue()); 
    } 

    @Override 
    public int hashCode() 
    { 
     return value.hashCode(); 
    } 


    @Override 
    public String toString() 
    { 
     return description; 
    } 

Answer 1

將一個監聽器添加到您的按鈕，然後添加代碼以獲取您的組合框值爲一個字符串。

 JButton okButton = new JButton("OK"); 
     okButton.addActionListener(new ActionListener() { 
     public void actionPerformed(ActionEvent e) { 
      JComboBox jComboBox1 = (JComboBox) e.getSource(); 
      Item item = (Item) jComboBox1.getSelectedItem(); 
      String code = (String) item.getValue(); 
      System.out.println(code); 
     }   
     });