Java 将图像设置为 JPanel 背景的最简单方法

Simplest way to set image as JPanel background

提问by Joshua Martin

How would I add the backgroung image to my JPanel without creating a new class or method, but simply by inserting it along with the rest of the JPanel's attributes?

我如何将背景图像添加到我的 JPanel 而不创建新的类或方法，而只需将它与 JPanel 的其余属性一起插入？

I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class.

我正在尝试使用图像设置 JPanel 的背景，但是，我发现的每个示例似乎都建议使用自己的类扩展面板。

I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).

我一直在寻找一种方法来简单地添加图像，而无需创建一个全新的类并在相同的方法中（试图使事情井井有条和简单）。

Here is an example of the method that sets my JPanel:

这是设置我的 JPanel 的方法示例：

public static JPanel drawGamePanel(){
    //Create game panel and attributes
    JPanel gamePanel = new JPanel();
    Image background = Toolkit.getDefaultToolkit().createImage("Background.png");
    gamePanel.drawImage(background, 0, 0, null);
    //Set Return
    return gamePanel;
}

回答by Maxim Shoustin

As I know the way you can do it is to override paintComponentmethod that demands to inherit JPanel

据我所知，您可以这样做的paintComponent方法是覆盖需要继承的方法JPanel

 @Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g); // paint the background image and scale it to fill the entire space
    g.drawImage(/*....*/);
}

The other way (a bit complicated) to create second custom JPaneland put is as background for your main

创建第二个自定义JPanel并放置的另一种方式（有点复杂）是您主要的背景

ImagePanel

图像面板

public class ImagePanel extends JPanel
{
private static final long serialVersionUID = 1L;
private Image image = null;
private int iWidth2;
private int iHeight2;

public ImagePanel(Image image)
{
    this.image = image;
    this.iWidth2 = image.getWidth(this)/2;
    this.iHeight2 = image.getHeight(this)/2;
}


public void paintComponent(Graphics g)
{
    super.paintComponent(g);
    if (image != null)
    {
        int x = this.getParent().getWidth()/2 - iWidth2;
        int y = this.getParent().getHeight()/2 - iHeight2;
        g.drawImage(image,x,y,this);
    }
}
}

EmptyPanel

空面板

public class EmptyPanel extends JPanel{

private static final long serialVersionUID = 1L;

public EmptyPanel() {
    super();
    init();
}

@Override
public boolean isOptimizedDrawingEnabled() {
    return false;
}


public void init(){

    LayoutManager overlay = new OverlayLayout(this);
    this.setLayout(overlay);

    ImagePanel iPanel = new ImagePanel(new IconToImage(IconFactory.BG_CENTER).getImage());
    iPanel.setLayout(new BorderLayout());   
    this.add(iPanel);
    iPanel.setOpaque(false);                
}
}

IconToImage

图标到图像

public class IconToImage {

Icon icon;
Image image;


public IconToImage(Icon icon) {
    this.icon = icon;
    image = iconToImage();
}

public Image iconToImage() { 
    if (icon instanceof ImageIcon) { 
        return ((ImageIcon)icon).getImage(); 
    } else { 
        int w = icon.getIconWidth(); 
        int h = icon.getIconHeight(); 
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); 
        GraphicsDevice gd = ge.getDefaultScreenDevice(); 
        GraphicsConfiguration gc = gd.getDefaultConfiguration(); 
        BufferedImage image = gc.createCompatibleImage(w, h); 
        Graphics2D g = image.createGraphics(); 
        icon.paintIcon(null, g, 0, 0); 
        g.dispose(); 
        return image; 
    } 
}


/**
 * @return the image
 */
public Image getImage() {
    return image;
}
}

回答by Sage

I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class

我正在尝试使用图像设置 JPanel 的背景，但是，我发现的每个示例似乎都建议使用自己的类扩展面板

yes you will have to extend JPaneland override the paintcomponent(Graphics g)function to do so.

是的，您必须扩展JPanel和覆盖该paintcomponent(Graphics g)功能才能这样做。

@Override
  protected void paintComponent(Graphics g) {

    super.paintComponent(g);
        g.drawImage(bgImage, 0, 0, null);
}

I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).

我一直在寻找一种方法来简单地添加图像，而无需创建一个全新的类并使用相同的方法（试图使事情井井有条和简单）。

You can use other component which allows to add image as icon directly e.g. JLabelif you want.

您可以使用其他允许直接将图像添加为图标的组件，例如，JLabel如果您愿意。

ImageIcon icon = new ImageIcon(imgURL); 
JLabel thumb = new JLabel();
thumb.setIcon(icon);

But again in the bracket trying to keep things organized and simple!! what makes you to think that just creating a new class will lead you to a messy world ?

但是再次在括号中试图保持组织和简单！是什么让你认为仅仅创建一个新类就会导致你进入一个混乱的世界？

回答by camickr

Simplest way to set image as JPanel background

将图像设置为 JPanel 背景的最简单方法

Don't use a JPanel. Just use a JLabel with an Icon then you don't need custom code.

不要使用 JPanel。只需将 JLabel 与 Icon 一起使用，就不需要自定义代码。

See Background Panelfor more information as well as a solution that will paint the image on a JPanel with 3 different painting options:

有关更多信息以及将使用 3 种不同绘画选项在 JPanel 上绘制图像的解决方案，请参阅背景面板：

1. scaled
2. tiled
3. actual

1. 缩放
2. 平铺
3. 实际的

回答by javajon

Draw the image on the background of a JPanel that is added to the frame. Use a layout manager to normally add your buttons and other components to the panel. If you add other child panels, perhaps you want to set child.setOpaque(false).

在添加到框架的 JPanel 的背景上绘制图像。使用布局管理器通常将您的按钮和其他组件添加到面板。如果您添加其他子面板，也许您想设置 child.setOpaque(false)。

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

public class BackgroundImageApp {
    private JFrame frame;

    private BackgroundImageApp create() {
        frame = createFrame();
        frame.getContentPane().add(createContent());

        return this;
    }

    private JFrame createFrame() {
        JFrame frame = new JFrame(getClass().getName());
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        return frame;
    }

    private void show() {
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private Component createContent() {
        final Image image = requestImage();

        JPanel panel = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.drawImage(image, 0, 0, null);
            }
        };

        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        for (String label : new String[]{"One", "Dois", "Drei", "Quatro", "Peace"}) {
            JButton button = new JButton(label);
            button.setAlignmentX(Component.CENTER_ALIGNMENT);
            panel.add(Box.createRigidArea(new Dimension(15, 15)));
            panel.add(button);
        }

        panel.setPreferredSize(new Dimension(500, 500));

        return panel;
    }

    private Image requestImage() {
        Image image = null;

        try {
            image = ImageIO.read(new URL("http://www.johnlennon.com/wp-content/themes/jl/images/home-gallery/2.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return image;
    }

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

回答by Amit Tiwari

public demo1() {
    initComponents();
    ImageIcon img = new ImageIcon("C:\Users\AMIT TIWARI\Documents\NetBeansProjects\try\src\com\dd.jpeg"); //full path of image
    Image img2 = img.getImage().getScaledInstance(mylabel.getWidth(), mylabel.getHeight(),1);
    ImageIcon img3 = new ImageIcon(img2);
    mylabel.setIcon(img3);
}

回答by Sathvik

class Logo extends JPanel
{
    Logo()
    {
        //code
    }
    @Override
    public void paintComponent(Graphics g) 
    {
        super.paintComponent(g);
        ImageIcon img = new ImageIcon("logo.jpg");
        g.drawImage(img.getImage(), 0, 0, this.getWidth(), this.getHeight(), null);
    }
}