Question

我一直在使用提供的代码中名为infoPanel的JPanel，我希望能够在其前面精确放置带有JLabel的JTextField。我尝试过添加一个JLabel而无法放置在我想要的地方。我想把它比它提供的代码低20个像素，在它前面我想添加JTextField。我也想让JTextField只读。

如何准确放置JTextField和JLabel？

最佳做法是什么？

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.*;
import java.util.List;

@SuppressWarnings("serial")
public class DrawPanelMain extends JPanel {

private static final int PREF_W = 1200;
private static final int PREF_H = 700;
private List<Point> POINT_LIST = Arrays.asList(new Point[] {
        new Point(40, 40),
        new Point(40, 100),
        new Point(40, 160),
        new Point(40, 220),
        new Point(40, 280),
        new Point(40, 340),
        new Point(40, 400),
        new Point(40, 460),
        new Point(40, 520),
        new Point(40, 580),
        new Point(100, 100),
        new Point(100, 160),
        new Point(100, 220),
        new Point(100, 280),
        new Point(100, 340),
        new Point(100, 400),
        new Point(100, 460),
        new Point(100, 520),
        new Point(100, 580),
        new Point(160, 160),
        new Point(160, 220),
        new Point(160, 280),
        new Point(160, 340),
        new Point(160, 400),
        new Point(160, 460),
        new Point(160, 520),
        new Point(160, 580),
        new Point(220, 220),
        new Point(220, 280),
        new Point(220, 340),
        new Point(220, 400),
        new Point(220, 460),
        new Point(220, 520),
        new Point(220, 580),
        new Point(280, 280),
        new Point(280, 340),
        new Point(280, 400),
        new Point(280, 460),
        new Point(280, 520),
        new Point(280, 580),
        new Point(340, 340),
        new Point(340, 400),
        new Point(340, 460),
        new Point(340, 520),
        new Point(340, 580),
        new Point(400, 400),
        new Point(400, 460),
        new Point(400, 520),
        new Point(400, 580),
        new Point(460, 460),
        new Point(460, 520),
        new Point(460, 580),
        new Point(520, 520),
        new Point(520, 580),
        new Point(580, 580)
});
private JTabbedPane tabbedPane = new JTabbedPane();
private int tabIndex = 0;

public DrawPanelMain() {
    JPanel btnPanel = new JPanel();
    JPanel infoPanel = new JPanel();
    btnPanel.add(new JButton(new AddSwitchAction("Add Switch Panel")));
    btnPanel.add(new JButton(new PushConfigAction("Push Config")));
    btnPanel.add(new JButton(new ActivateAllAction("Activate All")));  //Button I want to work with
    infoPanel.add(new JTextField(20));

    setLayout(new BorderLayout());
    add(tabbedPane, BorderLayout.CENTER);
    add(btnPanel, BorderLayout.PAGE_END);
    add(infoPanel, BorderLayout.EAST);
}

@Override
public Dimension getPreferredSize() {
    if (isPreferredSizeSet()) {
        return super.getPreferredSize();
    }
    return new Dimension(PREF_W, PREF_H);
}

private class AddSwitchAction extends AbstractAction {
        public AddSwitchAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(0);
            putValue(MNEMONIC_KEY, mnemonic);
        }

    @Override
    public void actionPerformed(ActionEvent e) {
        tabIndex++;
        String title = "Switch " + tabIndex;
        DrawPanel2 tabComponent = new DrawPanel2(POINT_LIST);
        tabbedPane.add(title, tabComponent);
    }
}

private class PushConfigAction extends AbstractAction {
    public PushConfigAction(String name) {
        super(name);
        int mnemonic = (int) name.charAt(0);
        putValue(MNEMONIC_KEY, mnemonic);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        /*Add code sending the configuration to the switch panel*/
        JOptionPane.showMessageDialog(DrawPanelMain.this, "Configuration    Pushed to Panel");
    }
}

private class ActivateAllAction extends AbstractAction {
    public ActivateAllAction(String name) {
        super(name);
        int mnemonic = (int) name.charAt(1);
        putValue(MNEMONIC_KEY, mnemonic);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        Component comp = tabbedPane.getSelectedComponent();
        if (comp instanceof DrawPanel2) {
            DrawPanel2 drawPanel = (DrawPanel2) comp;
            drawPanel.activateAll();
        }
    }
}

private static void createAndShowGui() {
    DrawPanelMain mainPanel = new DrawPanelMain();
    final double version = 0.1;
    JFrame frame = new JFrame("RF Connection Panel " + version);
    frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    frame.getContentPane().add(mainPanel);
    frame.pack();
    frame.setLocationByPlatform(true);
    frame.setVisible(true);
}

public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGui();
        }
    });
}

}

@SuppressWarnings("serial")
class DrawPanel2 extends JPanel {
private static final int OVAL_WIDTH = 40;
private static final Color INACTIVE_COLOR = Color.RED;
private static final Color ACTIVE_COLOR = Color.green;
private List<Point> points;
private List<Ellipse2D> ellipses = new ArrayList<>();
private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>();

public DrawPanel2(List<Point> points) {
    this.points = points;
    for (Point p : points) {
        int x = p.x - OVAL_WIDTH / 2;
        int y = p.y - OVAL_WIDTH / 2;
        int w = OVAL_WIDTH;
        int h = OVAL_WIDTH;
        Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h);
        ellipses.add(ellipse);
        ellipseColorMap.put(ellipse, INACTIVE_COLOR);
     }

    MyMouseAdapter mListener = new MyMouseAdapter();
    addMouseListener(mListener);
    addMouseMotionListener(mListener);
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);
    for (Ellipse2D ellipse : ellipses) {
        g2.setColor(ellipseColorMap.get(ellipse));
        g2.fill(ellipse);
    }
}

private class MyMouseAdapter extends MouseAdapter {
    @Override
    public void mousePressed(MouseEvent e) {
        for (Ellipse2D ellipse : ellipses) {
            if (ellipse.contains(e.getPoint())) {
                Color c = ellipseColorMap.get(ellipse);
                c = (c == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR;
                ellipseColorMap.put(ellipse, c);
            }
        }
        repaint();
    }
}

public void activateAll() {
    for (Ellipse2D ellipse : ellipses) {
        ellipseColorMap.put(ellipse, ACTIVE_COLOR);
    }
    repaint();
}
}

Answer 1

如何精确放置JTextField和JLabels？

不要专注于此，专注于使用户界面的流程变得有意义且易于用户使用。

最佳做法是什么？

使用一个或多个适当的布局管理器，Insets布局管理器支持它们和/或Border它们不支持

例如......

Label and field

JPanel fields = new JPanel();
fields.add(new JLabel("Hello: "));
fields.add(new JTextField(20));
fields.setBorder(new EmptyBorder(20, 2, 0, 2));

infoPanel.add(fields);

有关详细信息，请参阅Laying Out Components Within a Container和How to Use Borders

JTextField剪裁

1 个答案: