Question

我正在使用Swing制作应用程序，我想在主面板上添加一个带有叉形图标的按钮。但是当我在其上绘制图像时，该图像正在呈现奇怪的图像。

我已经尝试过几种方法，例如在应用程序外部调整图像大小，并且十字叉是用IllustratorCC制作的，所以我认为这不是源图像的质量。

import javax.imageio.*;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;

public class ImageRenderingBadly extends JPanel
{
    BufferedImage cross;

    public ImageRenderingBadly()
    {
        try {
            URL url = new URL("https://i.imgur.com/cWGntek.png");
            cross = ImageIO.read(url);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void paintComponent(Graphics g)
    {
        g.drawImage(cross,0,0,null);
    }

    public static void main(String[] args)
    {
        JFrame frame = new JFrame();
        frame.setSize(new Dimension(200,200));
        frame.setBackground(new Color(0));

        ImageRenderingBadly panel = new ImageRenderingBadly();

        frame.setContentPane(panel);
        frame.setVisible(true);
    }
}

来源：

渲染效果很差

找到解决方案

在paintComponent：（https://docs.oracle.com/javase/tutorial/2d/advanced/quality.html）中使用抗锯齿

@Override
    public void paintComponent(Graphics g)
    {
        Graphics2D g2 = (Graphics2D)g;
        RenderingHints rh = new RenderingHints(
                RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY);
        g2.setRenderingHints(rh);
        g2.drawImage(cross,0,0,null);
    }

Result

Answer 1

它对我有用：

请注意，我已使用该图像创建了两张图像和图标，其中一个用于按钮，一个用于按下状态，以指示其已被按下。

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

public class XButtonTest {
    private static final String X_IMG_PATH = "https://i.imgur.com/cWGntek.png";

    public static void main(String[] args) {
        try {
            URL xImgUrl = new URL(X_IMG_PATH);
            BufferedImage xImage = ImageIO.read(xImgUrl);
            int w = xImage.getWidth();
            int h = xImage.getHeight();
            BufferedImage pressedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2 = pressedImg.createGraphics();
            g2.setColor(Color.LIGHT_GRAY);
            g2.fillRect(0, 0, w, h);
            g2.drawImage(xImage, 0, 0, null);
            g2.dispose();

            Icon icon = new ImageIcon(xImage);
            Icon pressedIcon = new ImageIcon(pressedImg);

            JButton button = new JButton(icon);
            button.setPressedIcon(pressedIcon);
            button.setBorderPainted(false);
            button.setFocusPainted(false);
            button.setContentAreaFilled(false);
            JPanel panel = new JPanel();
            panel.add(button);
            JOptionPane.showMessageDialog(null, panel, "Test", JOptionPane.PLAIN_MESSAGE);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 2

我发现“ drawImage”渲染的图像很差，这就是我认为的问题：


public class Panel extends JPanel
{
    BufferedImage image;

    public Panel() {
        super();

        try {
            image = ImageIO.read(new File("images/BMW-TA.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        g.drawImage(image, 0, 0, null);
    }
}

来源：https://i.imgur.com/ebr17CV.jpg

渲染：https://i.imgur.com/Z01I7mn.png

找到解决方案

在paintComponent中使用抗锯齿：

@Override
    public void paintComponent(Graphics g)
    {
        Graphics2D g2 = (Graphics2D)g;
        RenderingHints rh = new RenderingHints(
                RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY);
        g2.setRenderingHints(rh);
        g2.drawImage(cross,0,0,null);
    }

JButton图像渲染严重

2 个答案: