java - JOptionPane.showInputDialog 显示两次

Question

当我按下投诉框时，每个输入对话框都显示两次...我尝试删除 boxComplain.setSelected(true) 并且它有效(只显示一次)但是这使得复选框在我输入输入后消失.

    class CheckBoxListener implements ItemListener {  

    public void itemStateChanged(ItemEvent event) {  
    if(boxComplain.isSelected())

      {
          ab=JOptionPane.showInputDialog("Enter Reason of Complain: ");
          ac=JOptionPane.showInputDialog("Enter What The Complain is About: ");
          label4.setText("Complain request");
          boxComplain.setSelected(true);
      }
      }
      }

Answer 1

ItemListener 被调用两次——一次是在原始选择被更改时，第二次是在新选择被注册时。考虑改用 ActionListener。

另一个技巧是删除和添加 ItemListener:

     public void itemStateChanged(ItemEvent event) {
        if(boxComplain.isSelected()) {
           ab=JOptionPane.showInputDialog("Enter Reason of Complain: ");
           ac=JOptionPane.showInputDialog("Enter What The Complain is About: ");
           label4.setText("Complain request");
           boxComplain.removeItemListener(this);
           boxComplain.setSelected(true);
           boxComplain.addItemListener(this);
         }
     }