当图像在数组中时如何将图像添加到 JButton

Question

我正在尝试将图像添加到 Jbuttons。这些图像位于我使用单独的类创建的数组中。每次添加图像的尝试都失败了。我试图将它们变成 ImageIcon 并按原样添加它们，但它不起作用。第一组代码是我用来创建按钮并添加到 JFrame 的代码。我的目标是添加事件侦听器，以便在按下按钮时按钮将显示图像、矩形或带有文本的矩形

import java.awt.Dimension;
import java.awt.Image;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class ButtonTest extends JFrame{


    public ButtonTest(){

          JPanel panel = new JPanel();
          JButton[] b = new JButton[9];
          Image[] imgs = MyImageSplit.splitter("dog", 9);


          for (int i=0; i<b.length; i++){
             b[i]=new JButton();
             b[i].setPreferredSize(new Dimension(100, 100));

             panel.add(b[i]);
          }

        add(panel);  
        setVisible(true);
        setSize(400,400);
      }

        public static void main(String[] args) {
            new ButtonTest();

        }
}

这段代码是我用来分割图像并将较小的图像添加到数组中的代码。

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import javax.imageio.ImageIO;

public class MyImageSplit {

    public static Image[] splitter (String filename, int numGroup){
        int rows=(int) Math.sqrt(numGroup);
        int cols=(int) Math.sqrt(numGroup);

        BufferedImage[] buffimage = new BufferedImage[rows*cols];
        Image[] images = new Image[rows*cols];

        try{
            File file = new File(filename + ".jpg"); //gets image from directory
            FileInputStream f = new FileInputStream(file);
            BufferedImage img = ImageIO.read(f); //reads the image file



            //determines the width and height for each piece
            int pieceWidth=img.getWidth()/cols;
            int pieceHeight = img.getHeight()/rows;


            for (int x = 0; x < rows; x++) {
                for (int y = 0; y < cols; y++) {
                    //Initialize the image array with image pieces
                    buffimage[x * rows + y] = new BufferedImage(pieceWidth, pieceHeight, img.getType());

                    // draws the image piece
                    Graphics2D gr = buffimage[x * rows + y].createGraphics();
                    gr.drawImage(img, 0, 0, pieceWidth, pieceHeight, pieceWidth * y, pieceHeight * x, pieceWidth * y + pieceWidth, pieceHeight * x + pieceHeight, null);
                    gr.dispose();
                }
            }

            for (int i =0; i < buffimage.length; i++){
                ImageIO.write(buffimage[i], "jpg", new File(filename + i + ".jpg"));

            }
        }

        catch (Exception e) {
            System.out.println(e.getStackTrace());
        }

        for(int i = 0; i < rows*cols; i++){
            images[i] = (Image) buffimage[i];

        }

        return images;
    }

    public static void main(String[] args){
        splitter("monkey", 9);
    }

}

dog.jpg

Answer 1

您忘记为每个按钮添加图片。将此添加到您的for-loop：

for (int i=0; i<b.length; i++){
    b[i]=new JButton();
    b[i].setPreferredSize(new Dimension(200, 100));
    b[i].setIcon(new ImageIcon(imgs[i]));
    panel.add(b[i]);
}

此外，我建议您更改JButton 首选尺寸，因为图片不适合它们。

b[i].setPreferredSize(new Dimension(200, 100));

还有JFrame的大小。

setSize(800,400);

---

编辑：使用.png 图像文件扩展名来正确保持颜色。 .jpg 造成一些颜色的损失简单说。比较：

dog.jpg

dog.png

Answer 2

似乎您创建了按钮但从未设置它们的图像。

将以下行添加到ButtonTest 中的主循环：

b[i].setIcon(new ImageIcon(imgs[i]));