java - 消息对话框错误

Question

我收到此错误:

cannot find symbol
symbol: method showMessageDialog(<anonymous javax.swing.AbstractAction>,java.lang.String,java.lang.String,int)

有人可以帮助我吗？ 谢谢

 exitAction = new
 AbstractAction("Esci") {

             public void actionPerformed(ActionEvent e) {

             if (rcStatus ==1) {

    JOptionPane.showMessageDialog(this,
 "Thread running. Choose STOP before
 exit",
                     "Error", JOptionPane.ERROR_MESSAGE);


         }
          else {

                 System.exit(0);}

             }
         };
         exitAction.putValue(Action.NAME,
         "Exit");

         exitAction.putValue(Action.SHORT_DESCRIPTION,"Close");

Answer 1

JOptionPane 中没有具有该签名的方法。您确定您传入的 this 是 AbstractAction，而不是 Component。对于 showMessageDialog()，these are your options .

我想你想要JOptionPane.showMessageDialog(Component parentComponent, Object message, String title, int messageType) 。如果您没有合适的父组件可传入，请传递 null 而不是 this:

JOptionPane.showMessageDialog(null, "Thread running. Choose STOP before exit", "Error", JOptionPane.ERROR_MESSAGE);