JSeparator虚线样式

Question

我正在我的java swing应用程序中使用JSeparator。正常的实现使分隔符正常行；但是我需要的是分隔符应该是虚线(就像我们创建虚线边框一样)。我们有办法做到吗？

谢谢

Answer 1

您可以使用以下代码片段创建虚线。

import java.awt.Container;
import java.awt.Graphics;
import java.awt.GridLayout;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JSeparator;

public class SeparatorSample {
    public static void main(String args[]) {
        JFrame f = new JFrame("JSeparator Sample");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container content = f.getContentPane();
        content.setLayout(new GridLayout(0, 1));
        JLabel above = new JLabel("Above Separator");
        content.add(above);
        JSeparator separator = new JSeparator() {
            private static final long serialVersionUID = 1L;

            public void paintComponent(Graphics g) {
                for (int x = 0; x < 300; x += 15)
                    g.drawLine(x, 0, x + 10, 0);
            }
        };
        content.add(separator);
        JLabel below = new JLabel("Below Separator");
        content.add(below);
        f.setSize(300, 100);
        f.setVisible(true);
    }
}

Answer 2

要创建自定义JSeparator，您可以重写BasicSeparatorUI的paint()方法，讨论这里，并使用虚线Stroke (如图这里 )绘制直线。

增编:一种更熟悉的方法覆盖paintComponent()，如已接受的回答中所示，并方便地封装在此StrokedSeparator中。下面的变体用drawLine()替换为draw()，使用Line2D，它利用了笔画的几何形状。

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import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Stroke;
import java.awt.geom.Line2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import static javax.swing.JSeparator.*;

/**
 * @see https://stackoverflow.com/a/74657060/230513
 */
public class StrokeSepTest {

    private static final int N = 10;

    private void display() {
        var f = new JFrame("StrokeSepTest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        var stroke = new BasicStroke(8.0f, BasicStroke.CAP_BUTT,
            BasicStroke.JOIN_MITER, 10.0f, new float[]{5.0f}, 0.0f);
        var panel = new JPanel(new GridLayout(0, 1)) {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(320, 240);
            }
        };
        panel.setBackground(Color.white);
        for (int i = 0; i < N; i++) {
            Color color = Color.getHSBColor((float) i / N, 1, 1);
            panel.add(new StrokedSeparator(stroke, HORIZONTAL, color));
        }
        f.add(panel);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    // @see https://stackoverflow.com/a/74657060/230513 */
    private static class StrokedSeparator extends JSeparator {

        private Stroke stroke;

        public StrokedSeparator() {
            this(new BasicStroke(1F), HORIZONTAL);
        }

        public StrokedSeparator(int orientation) {
            this(new BasicStroke(1F), orientation);
        }

        public StrokedSeparator(Stroke stroke) {
            this(stroke, HORIZONTAL);
        }

        public StrokedSeparator(Stroke stroke, int orientation) {
            super(orientation);
            this.stroke = stroke;
        }

        public StrokedSeparator(Stroke stroke, int orientation, Color color) {
            super(orientation);
            super.setForeground(color);
            this.stroke = stroke;
        }

        @Override
        public void paintComponent(Graphics g) {
            var graphics = (Graphics2D) g;
            var s = getSize();
            graphics.setStroke(stroke);
            graphics.setColor(getForeground());
            if (getOrientation() == JSeparator.VERTICAL) {
                graphics.draw(new Line2D.Double(0, 0, 0, s.height));
            } else // HORIZONTAL
            {
                graphics.draw(new Line2D.Double(0, 0, s.width, 0));
            }
        }
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new StrokeSepTest()::display);
    }
}

Answer 3

对垃圾神的回答稍作修改后，我发现使用paintComponent()而不是paint()对我非常有用：

Stroke stroke = new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER, 10.0f, new float[] { 5.0f },
        0.0f);
JSeparator separator = new StrokedSeparator(stroke);
// Add separator to container

下面是StrokedSeparator类：

import java.awt.BasicStroke;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Stroke;

import javax.swing.JSeparator;

public class StrokedSeparator extends JSeparator {

    private static final long serialVersionUID = 1L;

    private Stroke stroke;

    public StrokedSeparator() {
        this(new BasicStroke(1F), HORIZONTAL);
    }

    public StrokedSeparator(int orientation) {
        this(new BasicStroke(1F), orientation);
    }

    public StrokedSeparator(Stroke stroke) {
        this(stroke, HORIZONTAL);
    }

    public StrokedSeparator(Stroke stroke, int orientation) {
        super(orientation);
        this.stroke = stroke;
    }

    @Override
    public void paintComponent(Graphics g) {
        Dimension s = getSize();

        Graphics2D graphics = (Graphics2D) g.create();
        graphics.setStroke(stroke);

        if (getOrientation() == JSeparator.VERTICAL) {
            graphics.setColor(getForeground());
            graphics.drawLine(0, 0, 0, s.height);

            graphics.setColor(getBackground());
            graphics.drawLine(1, 0, 1, s.height);
        } else // HORIZONTAL
        {
            graphics.setColor(getForeground());
            graphics.drawLine(0, 0, s.width, 0);

            graphics.setColor(getBackground());
            graphics.drawLine(0, 1, s.width, 1);
        }
    }
}