java - JCombobox Listener如何在选择项目时启用它？

Question

我有一个 JComboBox，显示来自数据库患者_详细信息的名称

public void ComboItem() {

chooser.removeAllItems();
chooser.addItem("Please Select...");
try {   
         String sql="select * from Patients_Details";
         pst = conn.prepareStatement(sql);
         rs=pst.executeQuery();
        while (rs.next()) {
            String id = rs.getString("Patient_ID"); // Get the Id
            String name = rs.getString("Name"); // Get the Name 

            ComboItem comboItem = new ComboItem(id, name); // Create a new ComboItem
            chooser.addItem(comboItem); // Put it into the ComboBox
            String tmp=comboItem.getid();
        }
    } catch (SQLException sqle) {
        System.out.println(sqle);
    }
}

这是来自组合项类，仅返回名称而不返回 ID

  public String toString() {
    return this.name  ;
   }

我的问题是如何获取所选项目以便可以执行此操作我不知道如何执行此操作我已经尝试了所有一堆代码近 2 个小时任何帮助将不胜感激

注意我是 Java 初学者

  private void chooserPopupMenuWillBecomeInvisible(javax.swing.event.PopupMenuEvent evt) {

    try{
      String sql="select * from Patients_Details where Patient_ID=? ";
      pst=conn.prepareStatement(sql);
      rs=pst.executeQuery();
      if(rs.next()){
      String add1=rs.getString("Patient_ID");
      txtpatientid.setText(add1);
      String add2=rs.getString("Name");
      txtname.setText(add2);
      String add3=rs.getString("Age");
      txtage.setText(add3);
      String add4=rs.getString("Gender");
      txtgender.setText(add4);
      String add5=rs.getString("Date");
      txtdate.setText(add5);
       }
  }
  catch(Exception e) {
    JOptionPane.showMessageDialog(null,e ); 
  }
}  

Answer 1

只需将 ActionListener 添加到组合框即可。当调用 actionPerformed 时，您可以查找所选值并调用您需要的任何方法。

例如:

chooser.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        Object selectedValue = chooser.getSelectedValue();
        // carry on with what ever you need
    }
});

看看...

• How to write action listeners
• How to use combo boxes

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