按照这样写就行了。你按照这个改改。Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize = this.getSize();
if (frameSize.height > screenSize.height) {
frameSize.height = screenSize.height;
}
if (frameSize.width > screenSize.width) {
frameSize.width = screenSize.width;
}
this.setLocation((screenSize.width - frameSize.width) / 2,
(screenSize.height - frameSize.height) / 2);