Question

我想制作一个透明的按钮，直到用户用鼠标悬停在它上面，所以我创建了自己的类，它扩展了JButton。我测试了它，它确实使按钮透明，并确实检测到用户在它上面悬停时，但它后来不会使它变得不透明。我需要使用此代码更改什么？

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

public class TransparentButton extends JButton {

    boolean opaque = false, areaFilled = false, borderPainted = false;

    public TransparentButton(Icon icon) {
        super(icon);
        initialise();
    }

    public TransparentButton(String text) {
        super(text);
        initialise();
    }

    private void initialise() {
        super.setOpaque(opaque);
        super.setContentAreaFilled(areaFilled);
        super.setBorderPainted(borderPainted);
        super.addMouseListener(new MouseListener() {
            public void mouseEntered(MouseEvent e) {
                opaque = true;
                areaFilled = true;
                borderPainted = true;
            }

            public void mouseExited(MouseEvent e) {
                opaque = false;
                areaFilled = false;
                borderPainted = false;
            }

            public void mouseClicked(MouseEvent e) {}
            public void mousePressed(MouseEvent e) {}
            public void mouseReleased(MouseEvent e) {}
        });
    }
}

Answer 1

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

public class TransparentButton extends JButton {

    boolean opaque = false, areaFilled = false, borderPainted = false;

    public TransparentButton(Icon icon) {
        super(icon);
        initialise();
    }

    public TransparentButton(String text) {
        super(text);
        initialise();
    }

    private void initialise() {

        super.addMouseListener(new MouseListener() {
            public void mouseEntered(MouseEvent e) {
                opaque = true;
                areaFilled = true;
                borderPainted = true;
                reset();

            }

            public void mouseExited(MouseEvent e) {
                opaque = false;
                areaFilled = false;
                borderPainted = false;
                reset();
            }

            public void mouseClicked(MouseEvent e) {}
            public void mousePressed(MouseEvent e) {}
            public void mouseReleased(MouseEvent e) {}
        });
    }

    private void reset() {
        super.setOpaque(opaque);
        super.setContentAreaFilled(areaFilled);
        super.setBorderPainted(borderPainted);
    }
}

Answer 2

boolean opaque = false，areaFilled = false，borderPainted = false; 字段opaque，areaFilled和borderPainted是calss的局部变量。改变它不会影响晚餐班！

setOpaque，setContentAreaFilled和setBorderPainted方法背后有很多逻辑你应该用它

Answer 3

您需要添加MouseMotionListener代码，但最好是ChangeListener
您必须更改AlphaComposite的值

Answer 4

设置变量是不够的。您还必须在按钮上调用适当的方法：

        public void mouseEntered(MouseEvent e) {
                super.setOpaque(true);
                super.setContentAreaFilled(true);
                super.setBorderPainted(true);

        }

        public void mouseExited(MouseEvent e) {
                super.setOpaque(false);
                super.setContentAreaFilled(false);
                super.setBorderPainted(false);

        }

P.S：我没有测试过。但这似乎在逻辑上很明显enoguh

JButton子类不改变透明度

4 个答案: