java - 当我在匿名类中尝试时，为什么会收到此错误？

Question

我收到一条错误消息:

no suitable method found for showMessageDialog(<anonymous Runnable>,String,String,int)当我尝试使用 JOptionPane.show...方法。这是为什么？

private void connectivityChecker() {

    Runnable r = new Runnable() {
        @Override
        public void run() {
            try {
                Thread.sleep(3000);
            }catch(Exception exc) {
                System.out.println("Thread Interrupted !");
            }

            boolean isConnected = Internet.isConnected();
            if(!isConnected) {
                JOptionPane.showMessageDialog(this, "You have lost connectivity to the server", "Connection Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    };
    new Thread(r,"Connectivity Checker - UserGUI").start();
}

Answer 1

当您引用 this 时，它指向内部类，而不是您正在考虑的外部类。

尝试将该点告诉外部类，而不是匿名内部类。

 JOptionPane.showMessageDialog(OuterClassName.this, <--------
              "You have lost connectivity to the server", 
                  "Connection Error", JOptionPane.ERROR_MESSAGE);