我尝试使用Jxlayer和PBar扩展(使用来自here的MadProgrammer的响应)来将缩放功能添加到包含在JScrollPanel中的JPanel。 缩放本身工作正常,但当缩放的面板变得比包含JFrame大时,滚动条不会调整并保持不活动状态。 这是我的代码:
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
JPanel topPanel = new JPanel();
Integer[] zoomList = {50, 75, 100, 125, 150, 200};
JComboBox<Integer> zoomBox = new JComboBox<>(zoomList);
zoomBox.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
int value = (int) zoomBox.getSelectedItem();
double scale = value / 100d;
transformModel.setScale(scale);
}
});
topPanel.add(zoomBox);
Panel centerPanel = new TestPane();
JScrollPane scrollPane = new JScrollPane(synopticPanel);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.getViewport().setOpaque(false);
scrollPane.setOpaque(false);
frame.add(topPanel, BorderLayout.NORTH);
frame.add(synopticPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
并在Testpane类中
public class TestPane extends JPanel {
private JLayer<JComponent> layer;
private JPanel content;
public TestPane() {
content = new JPanel();
content.setLayout(null);
//Adding some components
transformModel = new DefaultTransformModel();
transformModel.setScaleToPreferredSize(true);
layer = TransformUtils.createTransformJLayer(content, transformModel, null);
setLayout(new BorderLayout());
add(layer);
}
感谢您的帮助