Question

我想要一个圆边的按钮。我的按钮的背景颜色为黄色。我无法获得按钮的圆形边缘。这是我正在尝试的代码

 class RoundedBorder implements Border {
        int radius;
        RoundedBorder(int radius) {
            this.radius = radius;
        }
        public Insets getBorderInsets(Component c) {
            return new Insets(this.radius+1, this.radius+1, this.radius+2, this.radius);
        }
        public boolean isBorderOpaque() {
            return true;
        }
        public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
            g.drawRoundRect(x,y,width-1,height-1,radius,radius);
        }
    }

jButton1.setText(aContinue);
        jButton1.setBackground(new java.awt.Color(255, 255, 0));
        jButton1.setBorder(new RoundedBorder(20));

我无法使用这段代码获得圆形边缘。以下是我的按钮的外观。

enter image description here

我希望圆边没有溢出的背景色。

Answer 1

选项1 - 使用图片

选项2 - 使用以下代码（摘自Make a button round）

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;

public class RoundButton extends JButton {
  public RoundButton(String label) {
    super(label);

// These statements enlarge the button so that it 
// becomes a circle rather than an oval.
    Dimension size = getPreferredSize();
    size.width = size.height = Math.max(size.width, 
      size.height);
    setPreferredSize(size);

// This call causes the JButton not to paint 
   // the background.
// This allows us to paint a round background.
    setContentAreaFilled(false);
  }

// Paint the round background and label.
  protected void paintComponent(Graphics g) {
    if (getModel().isArmed()) {
// You might want to make the highlight color 
   // a property of the RoundButton class.
      g.setColor(Color.lightGray);
    } else {
      g.setColor(getBackground());
    }
    g.fillOval(0, 0, getSize().width-1, 
      getSize().height-1);

// This call will paint the label and the 
   // focus rectangle.
    super.paintComponent(g);
  }

// Paint the border of the button using a simple stroke.
  protected void paintBorder(Graphics g) {
    g.setColor(getForeground());
    g.drawOval(0, 0, getSize().width-1, 
      getSize().height-1);
  }

// Hit detection.
  Shape shape;
  public boolean contains(int x, int y) {
// If the button has changed size, 
   // make a new shape object.
    if (shape == null || 
      !shape.getBounds().equals(getBounds())) {
      shape = new Ellipse2D.Float(0, 0, 
        getWidth(), getHeight());
    }
    return shape.contains(x, y);
  }

// Test routine.
  public static void main(String[] args) {
// Create a button with the label "Jackpot".
    JButton button = new RoundButton("Jackpot");
    button.setBackground(Color.green);

// Create a frame in which to show the button.
    JFrame frame = new JFrame();
    frame.getContentPane().setBackground(Color.yellow);
    frame.getContentPane().add(button);
    frame.getContentPane().setLayout(new FlowLayout());
    frame.setSize(150, 150);
    frame.setVisible(true);
  }
}

选项3 - 使用支持圆形按钮的外观http://www.oracle.com/webfolder/technetwork/tutorials/obe/java/NimbusLookandFeel_OBE2012/CustomizingLandF.html

Option4 - 使用JavaFX并使用CSS。有免费的CSS脚本支持此

Answer 2

通过oracle找到了这个很好的例子，它提供了一个创建RoundButton的类。

enter image description here

以下是使用已编辑的RoundButton类创建RoundedButton类：

的示例

enter image description here

import java.awt.AWTEvent;
import java.awt.AWTEventMulticaster;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;


public class Test {

    public Test() {
        initComponents();
    }

    private void initComponents() {
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        final JTextField tf = new JTextField("");

        RoundedButton rb = new RoundedButton("Go");
        rb.setBackground(Color.yellow);
        rb.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                JOptionPane.showMessageDialog(frame, "You said: " + tf.getText());
            }
        });

        frame.add(tf, BorderLayout.NORTH);
        frame.add(rb);

        frame.pack();
        frame.setVisible(true);
    }

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

class RoundedButton extends Component {

    ActionListener actionListener;     // Post action events to listeners
    String label;                      // The Button's text
    protected boolean pressed = false; // true if the button is detented.

    /**
     * Constructs a RoundedButton with no label.
     */
    public RoundedButton() {
        this("");
    }

    /**
     * Constructs a RoundedButton with the specified label.
     *
     * @param label the label of the button
     */
    public RoundedButton(String label) {
        this.label = label;
        enableEvents(AWTEvent.MOUSE_EVENT_MASK);
    }

    /**
     * gets the label
     *
     * @see setLabel
     */
    public String getLabel() {
        return label;
    }

    /**
     * sets the label
     *
     * @see getLabel
     */
    public void setLabel(String label) {
        this.label = label;
        invalidate();
        repaint();
    }

    /**
     * paints the RoundedButton
     */
    @Override
    public void paint(Graphics g) {

        // paint the interior of the button
        if (pressed) {
            g.setColor(getBackground().darker().darker());
        } else {
            g.setColor(getBackground());
        }
        g.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 20, 20);

        // draw the perimeter of the button
        g.setColor(getBackground().darker().darker().darker());
        g.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 20, 20);

        // draw the label centered in the button
        Font f = getFont();
        if (f != null) {
            FontMetrics fm = getFontMetrics(getFont());
            g.setColor(getForeground());
            g.drawString(label, getWidth() / 2 - fm.stringWidth(label) / 2, getHeight() / 2 + fm.getMaxDescent());
        }
    }

    /**
     * The preferred size of the button.
     */
    @Override
    public Dimension getPreferredSize() {
        Font f = getFont();
        if (f != null) {
            FontMetrics fm = getFontMetrics(getFont());
            int max = Math.max(fm.stringWidth(label) + 40, fm.getHeight() + 40);
            return new Dimension(max, max);
        } else {
            return new Dimension(100, 100);
        }
    }

    /**
     * The minimum size of the button.
     */
    @Override
    public Dimension getMinimumSize() {
        return new Dimension(100, 100);
    }

    /**
     * Adds the specified action listener to receive action events from this
     * button.
     *
     * @param listener the action listener
     */
    public void addActionListener(ActionListener listener) {
        actionListener = AWTEventMulticaster.add(actionListener, listener);
        enableEvents(AWTEvent.MOUSE_EVENT_MASK);
    }

    /**
     * Removes the specified action listener so it no longer receives action
     * events from this button.
     *
     * @param listener the action listener
     */
    public void removeActionListener(ActionListener listener) {
        actionListener = AWTEventMulticaster.remove(actionListener, listener);
    }

    /**
     * Determine if click was inside round button.
     */
    @Override
    public boolean contains(int x, int y) {
        int mx = getSize().width / 2;
        int my = getSize().height / 2;
        return (((mx - x) * (mx - x) + (my - y) * (my - y)) <= mx * mx);
    }

    /**
     * Paints the button and distribute an action event to all listeners.
     */
    @Override
    public void processMouseEvent(MouseEvent e) {
        Graphics g;
        switch (e.getID()) {
            case MouseEvent.MOUSE_PRESSED:
                // render myself inverted....
                pressed = true;

                // Repaint might flicker a bit. To avoid this, you can use
                // double buffering (see the Gauge example).
                repaint();
                break;
            case MouseEvent.MOUSE_RELEASED:
                if (actionListener != null) {
                    actionListener.actionPerformed(new ActionEvent(
                            this, ActionEvent.ACTION_PERFORMED, label));
                }
                // render myself normal again
                if (pressed == true) {
                    pressed = false;

                    // Repaint might flicker a bit. To avoid this, you can use
                    // double buffering (see the Gauge example).
                    repaint();
                }
                break;
            case MouseEvent.MOUSE_ENTERED:

                break;
            case MouseEvent.MOUSE_EXITED:
                if (pressed == true) {
                    // Cancel! Don't send action event.
                    pressed = false;

                    // Repaint might flicker a bit. To avoid this, you can use
                    // double buffering (see the Gauge example).
                    repaint();

                    // Note: for a more complete button implementation,
                    // you wouldn't want to cancel at this point, but
                    // rather detect when the mouse re-entered, and
                    // re-highlight the button. There are a few state
                    // issues that that you need to handle, which we leave
                    // this an an excercise for the reader (I always
                    // wanted to say that!)
                }
                break;
        }
        super.processMouseEvent(e);
    }
}

Answer 3

另一种实现这一目标的简洁方法是定义一个可以绘制圆角按钮的自定义ButtonUI。

带圆边的纽扣

3 个答案: