Java g、 drawImage未成功，完全被难倒

我试图画一幅图像，但我不知道为什么它没有出现在屏幕上。图像加载良好

System.out.printf（“%n层1.img层播放器1为：”+Player层1.img层播放器1）；表示图像加载正确（正确的图像w/h等）

尝试过各种图像观察者，从不同的类（即Player_1.drawSquare和MyPanel.painComponent）绘制图像

有来自控件类的常规repaint（）请求，但我不认为这会阻止绘图

不会抛出任何错误

player_1.gif位于game_2包中，我已尝试在src和root文件夹中使用它运行代码

package test;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.net.URL;
public class Main{
 public static void main(String[] args) {
     GUI.main(args);
 }
}

class GUI {
static JFrame f = new JFrame("Swing Paint Demo");
    public static void main(String[] args) {

    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGUI(); 
        }
    });
}

private static void createAndShowGUI() {
    System.out.printf("%nCreated GUI on EDT? "+
    SwingUtilities.isEventDispatchThread());

    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    f.add(new MyPanel());
    f.setSize(640,640);
    f.setVisible(true);


} 

}

class MyPanel extends JPanel {

public MyPanel() {

    //setBorder(BorderFactory.createLineBorder(Color.black));
}


public Dimension getPreferredSize() {
    return new Dimension(640,640);
}

public void paintComponent(Graphics g) {
    super.paintComponent(g);       
    System.out.printf("%nPaincomponent on GUI");

    Player_1.paintSquare(g);
    System.out.printf("%nPlayer_1.img_player1 is: "+Player_1.img_player1);

}

}

class Player_1{
public static Image img_player1;
public int int_x = 0;
public int int_y = 1;
public int int_w = 1;
public int int_h = 1;

public static void paintSquare(Graphics g){
     if (img_player1 == null)
         img_player1 = IOControl.getImage("player_1.gif");

    g.drawImage(img_player1, 32, 32, 32, 32, GUI.f);

}
}
class IOControl {

public static void main(String[] args) {

}

static BufferedImage getImage(String path)
{

    BufferedImage tempImage = null;
        try
        {

                URL imageURL = Main.class.getResource(path);
                tempImage = toBufferedImage(Toolkit.getDefaultToolkit().getImage(imageURL));
        }
        catch(Exception e)
        {
                System.out.printf("%nAn error occured -" + e.getMessage());
        }
        System.out.printf("%n"+path);
        System.out.printf("%nIOControl.path");

        System.out.printf("%n"+tempImage);
        System.out.printf("%nIOControl.tempImage");
        return tempImage;


}

public static BufferedImage toBufferedImage(Image img)
{
    if (img instanceof BufferedImage)
    {
        return (BufferedImage) img;
    }

    // Create a buffered image with transparency
    BufferedImage bimage = new BufferedImage(32, 32, BufferedImage.TYPE_INT_ARGB);

    // Draw the image on to the buffered image
    Graphics2D bGr = bimage.createGraphics();
    bGr.drawImage(img, 0, 0, null);
    bGr.dispose();

    // Return the buffered image
    return bimage;
}
}

不要调用

main

方法。这意味着JVM可以调用它作为程序的起点。另外，无论在哪个类中是启动类，都应该只有一个

main

方法

不要在

paintXxx

方法中创建图像。您应该在构造函数中创建

我在原始帖子的评论中提到的所有其他错误点

看起来您的主要问题在于

getImage

方法。我为您简化了它，并且它是有效的（考虑到我修复了上面提到的其他点）

下面是完整的运行代码。注意：图像位置正确，与

Main

类位于同一个包中

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

public class Main {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new GUI().createAndShowGUI();
            }
        });
    }
}

class GUI {

    JFrame f = new JFrame("Swing Paint Demo");

    public void createAndShowGUI() {
        System.out.printf("%nCreated GUI on EDT? "
                + SwingUtilities.isEventDispatchThread());

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new MyPanel());
        f.setSize(640, 640);
        f.setVisible(true);

    }

}

class MyPanel extends JPanel {

    Player_1 player1;

    public MyPanel() {
        player1 = new Player_1(MyPanel.this);
    }

    public Dimension getPreferredSize() {
        return new Dimension(640, 640);
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        System.out.printf("%nPaincomponent on GUI");

        player1.paintSquare(g);

    }

}

class Player_1 {

    public Image img_player1;
    public int int_x = 0;
    public int int_y = 1;
    public int int_w = 1;
    public int int_h = 1;
    JPanel panel;

    public Player_1(JPanel panel) {
        this.panel = panel;
        img_player1 = IOControl.getImage("player_1.png");
    }

    public void paintSquare(Graphics g) {
        g.drawImage(img_player1, 32, 32, 32, 32, panel);
    }
}

class IOControl {

    public static BufferedImage getImage(String path) {
        BufferedImage img = null;
        try {
            img = ImageIO.read(GUI.class.getResource(path));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return img;
    }
}

---

1） 选择使用Java命名约定的更好的类名和变量。变量和类名使用驼峰式大小写。此外，您还使用类型

Player\u 1

命名了一个变量

Player\u 1

。我不确定这是否让你感到困惑，但对我来说确实如此。2） 不要不必要地使用

static

，这样做就太过分了。3） 不要使用将要绘制的方法创建图像

paintSquare

。4）显示您的<代码> IOrg.GeMimeG/<代码>方法，并提到“代码> > PraveRy1.GIF”<代码>位于您的文件结构中。5）考虑发布一个可编译的示例，我们可以测试。在它的当前状态下，由于缺少类，它是不可编译的。去掉不必要的代码并包含必要的类。确保它已编译，然后用示例编辑您的帖子。仍然无法编译。为此，只创建一个.java文件，不管主启动类是什么类。将所有类都放入该文件中。在除主类之外的类名中，省略

public

。如果你可以创建一个文件来编译，那么我们也应该能够测试它。我已经用player_1.gif位置和IOControl.getImage方法更新了帖子。我目前正在制作一个可编译的示例。

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

public class Main {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new GUI().createAndShowGUI();
            }
        });
    }
}

class GUI {

    JFrame f = new JFrame("Swing Paint Demo");

    public void createAndShowGUI() {
        System.out.printf("%nCreated GUI on EDT? "
                + SwingUtilities.isEventDispatchThread());

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new MyPanel());
        f.setSize(640, 640);
        f.setVisible(true);

    }

}

class MyPanel extends JPanel {

    Player_1 player1;

    public MyPanel() {
        player1 = new Player_1(MyPanel.this);
    }

    public Dimension getPreferredSize() {
        return new Dimension(640, 640);
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        System.out.printf("%nPaincomponent on GUI");

        player1.paintSquare(g);

    }

}

class Player_1 {

    public Image img_player1;
    public int int_x = 0;
    public int int_y = 1;
    public int int_w = 1;
    public int int_h = 1;
    JPanel panel;

    public Player_1(JPanel panel) {
        this.panel = panel;
        img_player1 = IOControl.getImage("player_1.png");
    }

    public void paintSquare(Graphics g) {
        g.drawImage(img_player1, 32, 32, 32, 32, panel);
    }
}

class IOControl {

    public static BufferedImage getImage(String path) {
        BufferedImage img = null;
        try {
            img = ImageIO.read(GUI.class.getResource(path));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return img;
    }
}