@凯泽
我想我知道发生了什么事。如果将main（）方法放在 另一个类中 ，则一切正常。因此，您需要类似：
public class RootGUILauncher { public static void main(String[] args) { try { System.setProperty("apple.laf.useScreenMenuBar", "true"); System.setProperty("com.apple.mrj.application.apple.menu.about.name", "Test"); UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch(ClassNotFoundException e) { System.out.println("ClassNotFoundException: " + e.getMessage()); } catch(InstantiationException e) { System.out.println("InstantiationException: " + e.getMessage()); } catch(IllegalAccessException e) { System.out.println("IllegalAccessException: " + e.getMessage()); } catch(UnsupportedLookAndFeelException e) { System.out.println("UnsupportedLookAndFeelException: " + e.getMessage()); } javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { new RootGUI(); } });}然后将您的RootGUI类放在另一个文件中。
