java - JFrame 与 JscrollPane

Question

我正在尝试向 JScrollpane 添加一些面板，然后再添加到框架，但我无法滚动。 这是代码。

first_panel =  new JPanel();
first_panel.setBackground(Color.red);
second_panel =  new JPanel();
second_panel.setBackground(Color.blue);
third_panel =  new JPanel();
third_panel.setBackground(Color.green);
fourth_panel =  new JPanel();
fourth_panel.setBackground(Color.red);
fifith_panel =  new JPanel();
fifith_panel.setBackground(Color.blue);
six_panel =  new JPanel();
six_panel.setBackground(Color.green);
final_panel =  new JPanel();
final_panel.setLayout(null);
final_panel.setBackground(Color.gray);
final_panel.add(first_panel);
final_panel.add(second_panel);
final_panel.add(third_panel);
final_panel.add(fourth_panel);
final_panel.add(fifith_panel);
final_panel.add(six_panel);

first_panel.setBounds(10,10,200,100);
second_panel.setBounds(10,10,200,200);
third_panel.setBounds(10,10,200,300);
fourth_panel.setBounds(10,10,200,400);
fifith_panel.setBounds(10,10,200,500);
six_panel.setBounds(10,10,200,600);
panel_scroll = new JScrollPane(final_panel);
panel_scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);    
final_panel.setBounds(0,0,400,400);
// scroll_panel =  new JPanel();
// scroll_panel.setLayout(null);
// scroll_panel.add(panel_scroll);
// panel_scroll.setBounds(0,0,400,400);
frame.getContentPane().add(panel_scroll);

有人可以帮我解决这个问题吗？提前致谢。

Answer 1

• 使用标准LayoutManagers而不是AbsoluteLayout ，那么 Swing GUI 将连续或按比例调整大小 JFrame

• 使用GridLayout()对于 final_panel在所有JPanels的情况下可以在屏幕上获得相同的尺寸

• 覆盖 getPreferredSize对于 JPanel ，初始且正确 PreferredSize在屏幕上(final_panel 的尺寸大于 JScrollPane 的尺寸)

需要

• 来覆盖 ScrollPanel.setPreferredScrollableViewportSize(new Dimension(int, int)); ，然后调用JFrame.pack()初始且正确 PreferredSize在屏幕上

需要

• 来覆盖 JScrollPane.getVerticalScrollBar().setUnitIncrement(int);用于自然滚动