如何将图像添加到 JButton

Question

我正在尝试将图像添加到 JButton，但不确定我缺少什么。当我运行以下代码时，该按钮看起来与我在没有任何图像属性的情况下创建它时完全相同。 Water.bmp 位于我的项目文件夹的根目录中。

ImageIcon water = new ImageIcon("water.bmp");
    JButton button = new JButton(water);
    frame.add(button);

Answer 1

我认为你的问题在于图像的位置。您应该将其放置在源中，然后像这样使用它：

  JButton button = new JButton();
  try {
    Image img = ImageIO.read(getClass().getResource("resources/water.bmp"));
    button.setIcon(new ImageIcon(img));
  } catch (Exception ex) {
    System.out.println(ex);
  }

在本例中，假设图像位于 src/resources/ 文件夹中。

Answer 2

@Rogach

，您可能想添加：

// to remote the spacing between the image and button's borders
button.setMargin(new Insets(0, 0, 0, 0));
// to add a different background
button.setBackground( ... );
// to remove the border
button.setBorder(null);

Answer 3

它看起来像是一个位置问题，因为该代码非常适合添加图标。

由于我不知道您的文件夹结构，我建议添加一个简单的检查：

File imageCheck = new File("water.bmp");

if(imageCheck.exists()) 
    System.out.println("Image file found!")
else 
    System.out.println("Image file not found!");

这样，如果您的路径名错误，它会告诉您，而不是不显示任何内容。如果文件不存在，则应抛出异常。

Answer 4

您将图像放入资源文件夹中并使用以下代码：

JButton btn = new JButton("");
btn.setIcon(new ImageIcon(Class.class.getResource("/resources/img.png")));

Answer 5

public class ImageButton extends JButton {

    protected ImageButton(){
    }

    @Override
        public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        Image img = Toolkit.getDefaultToolkit().getImage("water.bmp");

        g2.drawImage(img, 45, 35, this);
        g2.finalize();
    }
}

---

或使用此代码

class MyButton extends JButton {

    Image image;
    ImageObserver imageObserver;


    MyButtonl(String filename) {
            super();
            ImageIcon icon = new ImageIcon(filename);
            image = icon.getImage();
            imageObserver = icon.getImageObserver();
        }

     public void paint( Graphics g ) {
            super.paint( g );
            g.drawImage(image,  0 , 0 , getWidth() , getHeight() , imageObserver);
        }
    }

Answer 6

我只做了一件事，它对我有用..检查你的代码是否有这个方法..

setResizable(false);

如果它是假的，那就让它为真，它会工作得很好..
我希望它有帮助..

Answer 7

buttonB.setIcon(new ImageIcon(this.getClass().getResource("imagename")));

Answer 8

//paste required image on C disk
JButton button = new JButton(new ImageIcon("C:water.bmp");

Answer 9

这段代码对我有用：

    BufferedImage image = null;
    try {
        URL file = getClass().getResource("water.bmp");
        image = ImageIO.read(file);
    } catch (IOException ioex) {
        System.err.println("load error: " + ioex.getMessage());
    }
    ImageIcon icon = new ImageIcon(image);
    JButton quitButton = new JButton(icon);

Answer 10

例如，如果文件夹 res/image.png 中有图像，您可以这样写：

try
{
    ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
    InputStream input = classLoader.getResourceAsStream("image.png");
    // URL input = classLoader.getResource("image.png"); // <-- You can use URL class too.
    BufferedImage image = ImageIO.read(input);

    button.setIcon(new ImageIcon(image));
}
catch(IOException e)
{
    e.printStackTrace();
}

在一行中：

try
{
    button.setIcon(new ImageIcon(ImageIO.read(Thread.currentThread().getContextClassLoader().getResourceAsStream("image.png"))));
}
catch(IOException e)
{
    e.printStackTrace();
}

如果图像比按钮大，则不会显示。

Answer 11

日食示例：
读完上面的内容后，我仍然需要更多的研究来了解如何使用 eclipse 放置图像资源以及如何放置图像资源。
结果：在 Eclipse 中，您需要将图像存储在任何“源文件夹”（例如“src”）下或“文件夹”下面。
您可以通过右键单击项目“新建”->“源文件夹”或“新建”->“文件夹”来创建这两个文件夹。任何文件夹名称都可以。 “<源文件夹>/<图像文件夹>”的示例是“src/images”或“resource/img”。
下面是一些功能齐全的示例代码，需要两个按钮图像，“Button-Image-Up.png”和“Button-Image-Down.png”位于文件夹“images”中：

import javax.swing.JDialog;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class ImageButtonDlg extends JDialog {
    // define button images and fall-back text
    private static gstrTxt="<Button Fall-back Text>"; // in case image does not load
    private static String gstrImgUp="Button-Image-Up.png";   // regular image
    private static String gstrImgDown="Button-Image-Down.png"; // button pressed image
    private static String gstrImgFolder="images";   // image folder, "/images" is also fine
    public static void main(String[] args) {
        ImageButtonDlg dialog = new ImageButtonDlg();
        dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        dialog.setVisible(true);
    }
    /**
     * Create the dialog.
     */
    public ImageButtonDlg() {
        initializeDialog();
    }
    /**
     * Create a new ImageIcon from an image resource. 
     * The input can be: 
     * - an image file name, e.g. <image.png> 
     * - a relative path, e.g. <image/image.png>
     * - an absolute path, e.g. </home/user/dev/image.png>
     * In eclipse, images can be stored below any project "Source folder", 
     * such as "src".
     * ├── src
     * │   ├── img1.png
     * │   └── images
     * │       └── img2.png
     * ├── resources
     * │   ├── img3.png
     * │   └── images
     * │       └── img4.png
     * └── img5.png
     *  In above example img1.png to img4.png are found by 
     *  image file name or relative path
     *  However, img5 is stored in the project root folder and 
     *  needs an absolute path.
     *    
     * @param strImagePath - image filename, absolute path or relative path
     * @return new ImageIcon or 'null' if load fails
     */    
    public static ImageIcon getResourceImageIcon(String strFilepath) {
        ClassLoader loader = null;
        URL url = null;
        Image img=null;
        ImageIcon imgIcon=null;
        loader = ImageButtonDlg.class.getClassLoader();
        System.out.println(loader.toString());
        try {  // file location: <a relative path>
            url = loader.getResource("images/"+strFilepath);
            if(url==null) {
                System.out.printf("ImageButtonDlg.class.getResource(%s)=>null\n", "images/"+strFilepath);
            }
        } catch (Exception e0) {
            e0.printStackTrace();
        }
        if(url==null) {
            try {  // file location: <image filename>
                url = loader.getResource(strFilepath);
                if(url==null) { 
                    System.out.printf("Util.class.getResource(%s)=>null\n", strFilepath);
                }
            } catch (Exception e1) {
                e1.printStackTrace();
            }
        }
        try {
            img = ImageIO.read(url);
        } catch (Exception e2) {
            e2.printStackTrace();
            System.exit(0);
        }
        if (img!=null){
            imgIcon = new ImageIcon(img);
        }
        return imgIcon;
    }
    /**
     * Create JButton with Image
     * In case Image load fails, we create a JButton with text
     * @param strImgPath - path to Image
     * @param strAltText - fall-back text
     * @return
     */
    public static JButton getNewJButtonWithImageIcon(String strImgPath, String strAltText) {
        JButton btnReturn = null;
        ImageIcon imgIcon = getResourceImageIcon(strImgPath);
        if (imgIcon!=null){
            btnReturn = new JButton(imgIcon);
        }
        else {
            btnReturn = new JButton(strAltText);
        }
        return btnReturn;
    }
    /**
     * Image button was pressed, display a message box
     */
    private void actionImageButtonPressed() {
        try {
            JOptionPane.showMessageDialog(null, "Image Button was pressed", "Info", JOptionPane.INFORMATION_MESSAGE);
        }
        catch (Exception e) {
            ; // ignore
        }
    }
    /**
     * Initialize the dialog
     * add a button panel and the image button to the window/content pane
     */
    private void initializeDialog()
    {
        this.setTitle("Image Button Example");
        this.setResizable(false);
        this.setBounds(200, 200, 699, 601);
        JPanel panelButton = new JPanel();
        panelButton.setLayout(new FlowLayout(FlowLayout.RIGHT)); // all buttons in a row
        getContentPane().add(panelButton, BorderLayout.SOUTH); // button pane at the bottom of the window
        // create the Image Button
        JButton btnImageButton = getNewJButtonWithImageIcon(gstrImgUp, gstrTxt);
        btnImageButton.setToolTipText("<Explain what pressing the Button does>");
        btnImageButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                actionImageButtonPressed();// The Action
            }
        });
        // load button image when button clicked/released
        btnImageButton.addMouseListener((MouseListener) new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                btnImageButton.setIcon(getResourceImageIcon(gstrImgDown));              
            }
            public void mouseReleased(MouseEvent e) {
                btnImageButton.setIcon(getResourceImageIcon(gstrImgUp));
            }
        });
        btnImageButton.setActionCommand("ImageButtonAction");
        // add button to button panel
        panelButton.add(btnImageButton);
    }
}

玩得开心！
沃尔克·弗罗利希
PS：
也许有人可以分享更多的实践经验。

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