ImageIcon不在java中显示

Question

该代码应该显示背景图像和播放器.但它只是一个粉红色的屏幕.我无法确定问题的来源,这是我的代码.

package main;

import java.awt.*;
import javax.swing.ImageIcon;    
import javax.swing.JFrame;

public class Images extends JFrame {

    public static void main(String Args[]) {

        DisplayMode dm = new DisplayMode(800, 600, 16, DisplayMode.REFRESH_RATE_UNKNOWN); // This is going to take 4 parameter, first 2 is x and y for resolotion. Bit depth, the number of bits in a cloour
                                                                                            // 16 is your bit depth. the last one is the monitor refresh, it means it will refres how much it wants
        Images i = new Images(); // making an object for this class
        i.run(dm); // making a run method and is taking the dm as a parameter, in this method we are putting stuff on the screen.
    }

    private Screen s; // Creating the Screen, from the Screen.java
    private Image bg; // Background
    private Image pic; // Face icon
    private boolean loaded; // Making the loaded

    //Run method
    private void run(DisplayMode dm) { // this is where we do things for the screen
        setBackground(Color.PINK); // Setting the Background
        setForeground(Color.WHITE); // Setting the ForeGround
        setFont(new Font("Arial", Font.PLAIN, 24)); // setting the font

        s = new Screen(); // now we can call ALL methods from the Screen object
        try {
            s.setFullScreen(dm, this); // This is setting the full screen, it takes in 2 parameters, dm is the display mode, so its setting the display settings, the next part is the this, what is just s, the screen object.
            loadpics(); // calling the loadpics method
            try { // so if that try block works, then it will put it to sleep for 5 seconds
                Thread.sleep(5000); // its doing this because, at the bottom (s.restorescreen) this makes it into a window again. so it needs to show it for 5 seconds.
            } catch (Exception ex) {
            }
        } finally {
            s.restoreScreen();
        }
    }

    // Loads Pictures
    private void loadpics() {
        System.out.println("Loadpics == true");
        bg = new ImageIcon("Users/georgebastow/Picture/background.jpg").getImage(); // Gets the background
        pic = new ImageIcon("Users/georgebastow/Picture/Player.png").getImage(); // Gets the Player
        System.out.println("Loaded == true in da future!");
        loaded = true; // If the pics are loaded then...    
    }

    public void paint(Graphics g) {
        if (g instanceof Graphics2D) { // This has to happen, its saying if g is in the class Graphics2D, so if we have the latest version of java, then this will run 
            Graphics2D g2 = (Graphics2D) g; // Were making the Text smooth but we can only do it on a graphcis2D object.
            g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON); // we are making the text aniti alias and turning it on!(it means making the text smooths! :) )
        }
        if(loaded == true){
            System.out.println("Loaded == true3");
            g.drawImage(bg,0,0,null);
            g.drawImage(pic, 170, 180, null);
            System.out.println("Loaded == true4");
        }
    }    
}

提前谢谢了

Answer 1

使用图像时,您希望通过URL加载它们Class.getResource(),返回URL.传递一个字符串ImageIcon将导致通过文件系统查找图像.虽然这可能在IDE的开发过程中起作用,但您会发现它在部署时不起作用.现在更好地进行更改.要使用此方法,您需要执行此操作

ImageIcon icon = new ImageIcon(Images.class.getResource("/Users/georgebastow/Picture/background.jpg"));

为了使其工作,您的文件结构需要看起来像这样

ProjectRoot
          src
             Users
                  georgebastow
                            Picture
                                  background.jpg

更常见的方法是将图像放在src中的reousrces文件夹中

ProjectRoot
          src
             resources
                     background.jpg

并使用此路径

ImageIcon icon = new ImageIcon(Images.class.getResource("/resources/background.jpg"));                     

构建时,IDE会将图像传输到类路径.

边注

• 不要在顶级容器上涂漆JFrame.而是使用JPanel或JComponent覆盖该paintComponent方法.如果使用JPanel,你也应该调用super.paintComponent的paintComponent方法.

• 像这样从Event Dispatch Thread 运行Swing应用程序

  public static void main(String[] args) {
      SwingUtiliities.invokeLater(new Runnable(){
          public void run() {
              new Images();
          }
      });
  }
  

  见初始线程

• 不要打电话Thread.sleep().当从EDT运行时(就像你应该的那样),你将阻止它.而是使用java.swing.Timer你正在寻找的if动画.即使它不是动画,仍然使用它!见这个例子的Timer程序.

• 同样正如@mKorbel所提到的,你永远不会在框架中添加任何内容.

UPDATE

运行此示例.我也忘了提,当你画上JPanel你的时候也想要覆盖getPreferredSize().这将为您的面板提供一个尺寸.

src/resources/stackoverflow5.png

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestImage {

    public TestImage() {
        JFrame frame = new JFrame("Test Image");
        frame.add(new NewImagePanel());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public class NewImagePanel extends JPanel {

        private BufferedImage img;

        public NewImagePanel() {
            try {
                img = ImageIO.read(TestImage.class.getResource("/resources/stackoverflow5.png"));
            } catch (IOException ex) {
                System.out.println("Could not load image");
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(600, 600);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new TestImage();
            }
        });
    }
}