我一直在抓取Oracle和Stack Overflow,试图找到解决我的问题的方法,但我还没有找到我想要的东西。
下面我有两个类,目前程序需要做的就是允许用户使用JFileChooser
打开图像文件并将其显示在 GUI 中(因此以后可以对其进行一些图像处理)
我已经测试了代码执行,我知道 ImageGUI
类中的变量img
正在初始化为我想要的第 99 行图片。我的问题是在pack();
图像之前在 GUI 中显示图像。
我错过了什么?
public class ImageEditLaunch {
public static void main(String[] args) {
ImageEditEngine program = new ImageEditEngine();
}
}
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
public class ImageEditEngine {
private static int[][][] originalImage;
private static BufferedImage originalImageBuffer;
public ImageEditEngine() {
originalImage = new int[0][0][0];
ImageGUI gui = new ImageGUI();
gui.setVisible(true);
}
public static ImageIcon openImage(String filepath){
try{
File f = new File(filepath);
BufferedImage image = ImageIO.read(f);
originalImageBuffer = image;
ImageIcon icon = new ImageIcon(image);
return icon;
}
catch(Exception e){
e.printStackTrace();
return new ImageIcon();
}
}
}
import java.awt.Dimension;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.UIManager;
public class ImageGUI extends JFrame implements ActionListener{
private JFrame window;
private JMenuItem mOpenFile;
private JMenuItem mSaveFile;
private JMenuItem mExitCommand;
private JMenuBar parentBar;
private JMenu fileMenu;
private JMenu commandMenu;
private JPanel mainPanel;
public ImageIcon img;
private JLabel mLabel;
public ImageGUI(){
super();
try{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch(Exception e){
e.printStackTrace();
}
//setup CommandMenu
commandMenu = makeMenu("Command", 'C');
//setup FileMenu
fileMenu = makeMenu("File", 'F');
mOpenFile = makeMenuItem(fileMenu, "Open...", 'O');
mSaveFile = makeMenuItem(fileMenu, "Save...", 'S');
mExitCommand = makeMenuItem(fileMenu, "Exit", 'X');
//setup parentBar
parentBar = new JMenuBar();
parentBar.add(fileMenu);
parentBar.add(commandMenu);
//main panel
mainPanel = new JPanel(new BorderLayout());
mLabel = new JLabel();
mainPanel.add(mLabel, BorderLayout.CENTER);
setJMenuBar(parentBar);
setSize(new Dimension(400, 300));
}
protected JMenuItem makeMenuItem(JMenu menu, String name, char mnemonic){
JMenuItem m = new JMenuItem(name, (int) mnemonic);
m.addActionListener(this);
menu.add(m);
return m;
}
protected JMenu makeMenu(String name, char mnemonic){
JMenu menu = new JMenu(name);
menu.setMnemonic(mnemonic);
return menu;
}
@Override
public void actionPerformed(ActionEvent arg0) {
if(arg0.getSource()==mOpenFile){
String path = null;
JFileChooser jfc = new JFileChooser();
jfc.setCurrentDirectory(new File("."));
int result = jfc.showOpenDialog(this);
if (result == JFileChooser.APPROVE_OPTION) {
File file = jfc.getSelectedFile();
path = file.getAbsolutePath();
}
img=ImageEditEngine.openImage(path);
mLabel= new JLabel(img);
mLabel.setVisible(true);
this.repaint();
pack();
}
}
}
紧接在 mLabel 上的 toString() 值:
mLabel = new JLabel(img);
如下
javax.swing.JLabel[,0,0,0x0,invalid,alignmentX=0.0,alignmentY=0.0,
border=,flags=8388608,maximumSize=,minimumSize=,preferredSize=,
defaultIcon=javax.swing.ImageIcon@2bd58ce,disabledIcon=,
horizontalAlignment=CENTER,horizontalTextPosition=TRAILING,
iconTextGap=4,labelFor=,text=,verticalAlignment=CENTER,
verticalTextPosition=CENTER]
根本问题是面板从未添加到框架中。代码还有许多其他问题,其中一些我修复了(通过删除它的整个部分),其他一些是我调整的。下面显示的代码还有其他问题需要修复(其中一两个我只是在懒惰编码中引入的 - 但它们不是致命的)。
话虽如此,此代码现在可以工作了。仔细查看以获取提示。请注意,这是一个热链接到图像的 MCVE,因此应该易于测试。
import java.awt.image.*;
import java.awt.*;
import javax.swing.*;
import javax.imageio.*;
import java.net.URL;
public class ImageEditEngine {
private static int[][][] originalImage;
private static BufferedImage originalImageBuffer;
public ImageEditEngine() {
originalImage = new int[0][0][0];
ImageGUI gui = new ImageGUI();
gui.setVisible(true);
}
public static ImageIcon openImage(){
try{
URL url = new URL("https://i.stack.imgur.com/OVOg3.jpg");
BufferedImage image = ImageIO.read(url);
originalImageBuffer = image;
ImageIcon icon = new ImageIcon(image);
return icon;
}
catch(Exception e){
e.printStackTrace();
return new ImageIcon();
}
}
public static void main(String[] args) {
new ImageEditEngine();
}
}
class ImageGUI extends JFrame {
private JPanel mainPanel;
public ImageIcon img;
private JLabel mLabel;
public ImageGUI(){
super();
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
try{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch(Exception e){
e.printStackTrace();
}
//main panel
mainPanel = new JPanel(new BorderLayout());
mLabel = new JLabel();
mainPanel.add(mLabel, BorderLayout.CENTER);
add(mainPanel);
setSize(new Dimension(400, 300));
img=ImageEditEngine.openImage();
mLabel.setIcon(img);
mLabel.setVisible(true);
this.repaint();
pack();
}
}
如果我想在GUI上显示图像,我将图像嵌入JLabel中。它工作得很好。
BufferedImage img = ImageIO.read(new File(IMG_PATH));
ImageIcon icon = new ImageIcon(img);
JLabel label = new JLabel(icon);
在 Java Swing 中显示图像
这应该有效!