java - 如何根据百分比使用拉绳方法更改范围像素的颜色

Question

我目前在程序中使用启动画面，然后在其上显示信息，例如文件的下载百分比。我想要像 JProgressBar 字符串一样，我的意思是，当蓝色进度经过字符串上方时，字符串的颜色会发生变化。

这是我当前正在使用的代码。

private static void splashProgress(float percent, String str)
{
    if (mySplash != null && mySplash.isVisible())
    {   // important to check here so no other methods need to know if there
        // really is a Splash being displayed
        float width = (186*percent)/100;
        splashProgress = new Rectangle2D.Double(4., 211., width, 24.);
        splashTextArea = new Rectangle2D.Double(width+4., 211., 186.-width, 24.);

        splashGraphics.setColor(new Color(255,177,100,255));
        splashGraphics.fill(splashProgress);

        splashGraphics.setColor(new Color(175,25,25,255));
        splashGraphics.fill(splashTextArea);
        splashGraphics.setColor(new Color(25,25,25,255));
        splashGraphics.drawString(str, 4,226);


        // make sure it's displayed
        mySplash.update();
    }
}

进度条如下所示:

如您所见，字符串的颜色与进度条的颜色相同，我希望将隐藏部分的颜色设置为不同的颜色。

感谢您的帮助，并对我的英语不好感到抱歉，这不是我的母语。

Answer 1

您使用Graphics2D#setXORMode

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TestGraphics {

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

    public TestGraphics() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setBackground(new Color(175,25,25,255));
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.setColor(new Color(255,177,100,255));
            g2d.fillRect(0, 0, getWidth() / 2, getHeight());
            g2d.setXORMode(new Color(175,25,25,255));
            FontMetrics fm = g2d.getFontMetrics();
            String text = "I'm some exciting text";
            int x = (getWidth() - fm.stringWidth(text)) / 2;
            int y = ((getHeight()- fm.getHeight()) / 2) + fm.getAscent();
            g2d.drawString(text, x, y);
            g2d.dispose();
        }

    }

}