Java 示例 - 在框架中显示颜色

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  问题描述

  如何在框架中显示颜色？
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  解决方案

  以下示例显示如何使用图像类的 setRGB 方法显示帧中的所有颜色。

  
  import java.awt.Graphics;
  import java.awt.event.WindowAdapter;
  import java.awt.event.WindowEvent;
  import java.awt.image.BufferedImage;
  import javax.swing.JComponent;
  import javax.swing.JFrame;
  public class Main extends JComponent {
     BufferedImage image;
     public void initialize() {
        int width = getSize().width;
        int height = getSize().height;
        int[] data = new int[width * height];
        int index = 0;
        
        for (int i = 0; i < height; i++) {
           int red = (i * 255) / (height - 1);
           for (int j = 0; j < width; j++) {
              int green = (j * 255) / (width - 1);
              int blue = 128;
              data[index++] = (red<<16) | (green<<8) | blue;
           }
        }
        image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        image.setRGB(0, 0, width, height, data, 0, width);
     }
     public void paint(Graphics g) {
        if (image == null)
        initialize();
        g.drawImage(image, 0, 0, this);
     }
     public static void main(String[] args) {
        JFrame f = new JFrame("Display Colours");
        f.getContentPane().add(new Main());
        f.setSize(300, 300);
        f.setLocation(100, 100);
        f.addWindowListener(new WindowAdapter() {
           public void windowClosing(WindowEvent e) {
              System.exit(0);
           }
        });
        f.setVisible(true);
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。

  
  Displays all the colours in a frame.
  

  以下是在框架中显示颜色的示例。

  
  import java.awt.Color;
  import java.awt.Dimension;
  import javax.swing.JFrame;
  import javax.swing.SwingUtilities;
  public class Panel { 
     public static void main(String[] args) { 
        SwingUtilities.invokeLater(new Runnable() { 
           public void run() { 
              displayJFrame();
           } 
        }); 
     } 
     static void displayJFrame() { 
        JFrame frame = new JFrame("Tutorialspoint");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setBackground(Color.red);
        frame.setPreferredSize(new Dimension(400, 300));
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
     }
  }