我已经使用GroupLayout创建了一个JPanel。我已将其作为选项卡添加到选项卡式窗格中，如下所示。
panel= new panel(this);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewportView(panel);
scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setPreferredSize(new Dimension(screenSize.width,screenSize.height));
tabbedPane.addTab("panel", null, scrollPane, null);
setLayout(groupLayout);
我可以看到滚动条，它在我的系统中滚动得很好，在屏幕尺寸大于/小于此滚动条的其他系统中，滚动条没有出现。
小组I已创建为
import java.awt.Color;
public class panel extends JPanel {
private static final long serialVersionUID = 1L;
private JTextField date = new JTextField();
private JTextArea reason = new JTextArea();
private JRadioButton yes = new JRadioButton("Yes");
private JRadioButton no = new JRadioButton("No");
private final JLabel by = new JLabel("Followup By");
private final JComboBox fo = new JComboBox();
private final JPanel panel_1 = new JPanel();
private JButton save;
private final JPanel panel = new JPanel();
private final JScrollPane scrollPane = new JScrollPane();
private final JTextArea textArea = new JTextArea();
/**
* Create the panel.
*/
public panel() {
setBackground(Color.WHITE);
ButtonGroup ButtonGroup = new ButtonGroup();
GroupLayout groupLayout = new GroupLayout(this);
groupLayout.setHorizontalGroup(
groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addComponent(panel_1, GroupLayout.PREFERRED_SIZE, 777, GroupLayout.PREFERRED_SIZE)
.addContainerGap(61, Short.MAX_VALUE))
);
groupLayout.setVerticalGroup(
groupLayout.createParallelGroup(Alignment.TRAILING)
.addGroup(Alignment.LEADING, groupLayout.createSequentialGroup()
.addContainerGap()
.addComponent(panel_1, GroupLayout.DEFAULT_SIZE, 414, Short.MAX_VALUE)
.addGap(142))
);
panel_1.setBorder(new TitledBorder(UIManager.getBorder("TitledBorder.border"), "Fo", TitledBorder.LEADING, TitledBorder.TOP, null, SystemColor.textHighlight));
panel_1.setLayout(null);
JLabel lblIsAFURequired = new JLabel("");
JLabel lblProposedDateOfFU = new JLabel("");
JLabel reason = new JLabel("");
lblIsAFURequired.setBounds(10, 169, 132, 14);
panel_1.add(lblIsAFURequired);
ButtonGroup.add(yes);
yes.setBounds(155, 165, 54, 23);
panel_1.add(yes);
ButtonGroup.add(no);
no.setBounds(211, 165, 60, 23);
panel_1.add(no);
no.setSelected(true);
lblProposedDateOfFU.setBounds(10, 194, 156, 14);
panel_1.add(lblProposedDateOfFU);
date.setBounds(161, 191, 86, 20);
panel_1.add(date);
date.setColumns(10);
date.setEnabled(false);
date.setEditable(false);
by.setBounds(10, 219, 86, 14);
panel_1.add(by);
fo.setEnabled(false);
fo.setBounds(161, 216, 67, 20);
panel_1.add(fo);
fo.setModel(new DefaultComboBoxModel(new String[] {"Doctor A", "Doctor B"}));
reason.setBounds(10, 244, 132, 14);
panel_1.add(reason);
/* reason.setEditable(false);
reason.setEnabled(false)*/;
reason.setBounds(10, 266, 735, 59);
panel_1.add(reason);
reason.setBackground(UIManager.getColor("Button.background"));
reason.setBorder(new LineBorder(new Color(0, 0, 0)));
reason.setLineWrap(true);
reason.setWrapStyleWord(true);
save = new JButton("Save ");
save.setBounds(310, 363, 186, 25);
panel_1.add(save);
save.setForeground(new Color(0, 0, 128));
save.setBackground(new Color(245, 245, 220));
panel.setBounds(10, 25, 748, 133);
panel_1.add(panel);
panel.setBorder(new TitledBorder(UIManager.getBorder("TitledBorder.border"), "Consultation Summary", TitledBorder.LEADING, TitledBorder.TOP, null, new Color(51, 153, 255)));
GroupLayout gl_panel = new GroupLayout(panel);
gl_panel.setHorizontalGroup(
gl_panel.createParallelGroup(Alignment.LEADING)
.addGap(0, 692, Short.MAX_VALUE)
.addGroup(gl_panel.createSequentialGroup()
.addContainerGap()
.addComponent(scrollPane, GroupLayout.DEFAULT_SIZE, 660, Short.MAX_VALUE)
.addContainerGap())
);
gl_panel.setVerticalGroup(
gl_panel.createParallelGroup(Alignment.LEADING)
.addGap(0, 133, Short.MAX_VALUE)
.addGroup(gl_panel.createSequentialGroup()
.addGap(2)
.addComponent(scrollPane, GroupLayout.DEFAULT_SIZE, 93, Short.MAX_VALUE)
.addContainerGap())
);
textArea.setWrapStyleWord(true);
textArea.setLineWrap(true);
textArea.setBorder(null);
textArea.setBackground(Color.WHITE);
scrollPane.setViewportView(textArea);
panel.setLayout(gl_panel);
no.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(no.isSelected()){
date.setEnabled(false);
date.setEditable(false);
date.setText("");
fo.setEditable(false);
fo.setEnabled(false);
reason.setEnabled(false);
reason.setEnabled(false);
reason.setBackground(SystemColor.menu);
}
}
});
yes.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(yes.isSelected()){
date.setEnabled(true);
date.setEditable(true);
fo.setEditable(true);
fo.setEnabled(true);
reason.setEnabled(true);
reason.setEnabled(true);
reason.setBackground(SystemColor.white);
}
}
});
setLayout(groupLayout);
}
}
任何帮助都会很棒
答案 0 :(得分：2)
您的布局代码太混乱了。有些代码似乎使用布局管理器而某些代码则没有。 Swing旨在与布局管理器一起使用。
如果您希望滚动窗格占据整个屏幕，则只需将滚动窗格添加到框架即可。默认情况下，JFrame使用BorderLayout，滚动窗格将放在CENTER中，这意味着滚动窗格将自动调整大小以填充整个框架。
不要在代码中的任何位置使用setBounds（）或setPreferredSize（）。当面板的首选大小大于滚动窗格的大小时，滚动窗格的滚动条将自动出现。布局管理器将为您计算首选大小，但如果您使用上述任一方法，它将无法正常工作。
我还建议您不要使用IDE来布局组件。
答案 1 :(得分：1)
尝试
JScrollPane scrollPane = new JScrollPane(panel);
或
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewport(panel);
或
JScrollPane scrollPane = new JScrollPane();
scrollPane.getViewport().add(panel);
而不是使用
scrollPane.setViewportView(panel);
请勿使用null布局，而应使用适当的布局，这就是它们的设计原因。
覆盖JComponent#getPreferredSize()而非使用setPreferredSize()
了解更多Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?