我想要展示一个带有图像的JButton,但是我不知道如何让鼠标悬停在上面时起作用。图片的正常显示可以工作。 另外,如果按钮上绘制的文本能够居中就更好了。
import java.awt.*;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
public class ImageButtonTest {
private static JButton imageButton;
public static void main(String[] args) throws IOException {
JFrame frm = new JFrame();
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setSize(90, 27);
frm.setLocation(50, 50);
Image image = ImageIO.read(new URL("http://i.imgur.com/bitgM6l.png"));
Image imageHover = ImageIO.read(new URL("http://i.imgur.com/dt81BWk.png"));
imageButton = new ImageButton(image, imageHover);
imageButton.setText("Download");
frm.add(imageButton);
frm.pack();
frm.setVisible(true);
}
static class ImageButton extends JButton {
private Image image, imageHover;
private boolean hover;
ImageButton(Image image, Image imageHover) {
this.image = image;
this.hover = false;
addMouseListener(new java.awt.event.MouseAdapter() {
@Override
public void mouseEntered(java.awt.event.MouseEvent evt) {
hover = true;
repaint();
}
@Override
public void mouseExited(java.awt.event.MouseEvent evt) {
hover = false;
repaint();
}
});
};
@Override
protected void paintComponent(Graphics g) {
if(isEnabled()) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2.setFont(new Font("Arial", Font.PLAIN, 12));
g2.setColor(Color.WHITE);
if(hover) {
g2.drawImage(imageHover, 0, 0, getWidth(), getHeight(), this);
} else {
g2.drawImage(image, 0, 0, getWidth(), getHeight(), this);
}
g2.drawString(getText(), 20, getHeight() / 2 + 5);
g2.dispose();
} else {
super.paintComponent(g);
}
}
}
}
setRolloverIcon(Icon)
方法。还有禁用图标、按下图标等方法,请参阅文档。 - Andrew Thompson