Question

我正在尝试对JButton版本进行操作，但不确定如何完成此操作。当按下按钮时，我可以执行一个动作。按下按钮时，它将图像更改为红色点，释放按钮时应将其更改为默认的绿色点。

如果有人可以向我指出释放按钮时如何创建动作的方向，这将是最有用的，下面是我的按钮按下代码。谢谢！

@Override
public void actionPerformed(ActionEvent e) {

    if (e.getSource() == change1) {

        p1a.setIcon(CLR); // THIS IS THE IMAGE WHEN BUTTON PRESSED
        // WOULD LIKE TO CHANGE BACK TO DEFAULT IMAGE HERE WHEN BUTTON IS RELEASED
    }
}

Answer 1

我不是在按钮本身上寻找图标来更改，而是在JPanel中寻找图像来更改。...虽然是相同的概念

很高兴提前提供这些信息

一种方法可能是将侦听器附加到ButtonModel并监视其状态更改...

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.image.BufferedImage;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private Icon normalIcon;
        private Icon pressedIcon;

        public TestPane() {
            setBorder(new EmptyBorder(16, 16, 16, 16));
            normalIcon = makeIcon(Color.GREEN);
            pressedIcon = makeIcon(Color.RED);

            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            JLabel label = new JLabel(normalIcon);
            JButton btn = new JButton("Pressy");

            add(btn, gbc);
            add(label, gbc);

            btn.getModel().addChangeListener(new ChangeListener() {
                @Override
                public void stateChanged(ChangeEvent e) {
                    ButtonModel model = btn.getModel();
                    if (model.isArmed()) {
                        label.setIcon(pressedIcon);
                    } else {
                        label.setIcon(normalIcon);
                    }
                }
            });
        }

        protected Icon makeIcon(Color color) {
            BufferedImage img = new BufferedImage(25, 25, BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2d = img.createGraphics();
            g2d.setColor(color);
            g2d.fillOval(0, 0, 25, 25);
            g2d.dispose();

            return new ImageIcon(img);
        }

    }

}

Answer 2

按下按钮时，它将图像更改为红点，释放按钮时应将其更改为默认的绿点。

这可以在JButton内完全实现。看到类似setPressedIcon(Icon) ..

E.G。

import javax.swing.*;
import java.net.*;

public class ButtonIcons {

    ButtonIcons() throws MalformedURLException {
        ImageIcon redIcon = new ImageIcon(new URL(
                "https://i.stack.imgur.com/wCF8S.png"));
        ImageIcon grnIcon = new ImageIcon(new URL(
                "https://i.stack.imgur.com/T5uTa.png"));
        JButton button = new JButton("Click me!", grnIcon);
        button.setPressedIcon(redIcon);
        JOptionPane.showMessageDialog(null, button);
    }

    public static void main(String[] args) {
        Runnable r = () -> {
            try {
                ButtonIcons o = new ButtonIcons();
            } catch (MalformedURLException ex) {
                ex.printStackTrace();
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

JButton释放动作

2 个答案: