我将您的Layout更改
JPanel为GridLayout，因此它的大小仅由Layoutmanager处理，取决于面板上的组件。
Jframe f = new Jframe(); f.setLayout(new BorderLayout()); f.setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE); JPanel p = new JPanel(new GridLayout(0, 5)); JScrollPane jsp = new JScrollPane(p); jsp.setPreferredSize(new Dimension(300,300)); jsp.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED); jsp.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED); for (int i = 0; i < 100; i++) { JButton b = new JButton("Button " + i); p.add(b); } f.add(jsp, BorderLayout.CENTER); f.setLocation(300, 300); f.setVisible(true); f.pack();
