如何在JPanel中显示图像 [英] How can I display an image in a JPanel
问题描述
我的问题是如何在JPanel中显示图像?我对如何做到这一点不清楚，这里的其他主题也提出了类似的要求.
My question here is how can I display an image into a JPanel? Other topics here asking something similar aren't clear to my about how can I do that.
我的项目文件夹中有一个目录，其中包含图像文件Project Folder/GUI/img，尤其是gray.png和green.png，它们要显示在JPanel中.
I have a directory in my project folder that have image files Project Folder/GUI/img, specifically gray.png and green.png which I want to display in a JPanel.
我尝试使用在其他帖子中找到的ImageIcon和JLabel的以下代码:
I tried with the following code using ImageIcon and JLabel that I found in other post:
ImageIcon image = new ImageIcon("GUI/img/gray.png");
JLabel label = new JLabel(image);
//JPanel panel is already initialized by the IDE
panel.add(label)
但是不起作用... JPanel保持空白，不显示任何图像.我该怎么办?
But doesn't work... The JPanel remain empty without displaying any image. How can I do that?
此外，我希望在执行某些操作(例如按下按钮)时，更改JPanel中的图像(对于green.png为gray.png).我可以通过相同的方法将其存档，以在JPanel中显示图像吗?
Additional to this, I want that the image inside the JPanel change (gray.png for green.png) when some action is performed, for example pressing a button. I can archive that by the same method for display the image in the JPanel right?
提前谢谢！
这是获得此测试代码的示例.初始化由IDE自动完成.
Here's an example of a test code for get this. The initialization is done automatically by the IDE.
import java.awt.Image;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
public class Sample extends javax.swing.JFrame {
public Sample() {
initComponents();
}
//Initialization
private void initComponents() {
PanelImage = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowOpened(java.awt.event.WindowEvent evt) {
formWindowOpened(evt);
}
});
javax.swing.GroupLayout PanelImageLayout = new javax.swing.GroupLayout(PanelImage);
PanelImage.setLayout(PanelImageLayout);
PanelImageLayout.setHorizontalGroup(
PanelImageLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 100, Short.MAX_VALUE)
);
PanelImageLayout.setVerticalGroup(
PanelImageLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 100, Short.MAX_VALUE)
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(61, 61, 61)
.addComponent(PanelImage, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(239, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(45, 45, 45)
.addComponent(PanelImage, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(155, Short.MAX_VALUE))
);
pack();
}
private void formWindowOpened(java.awt.event.WindowEvent evt) {
try {
DisplayImage(PanelImage, "/GUI/img/gray.png");
} catch (Exception ex) {
Logger.getLogger(Sample.class.getName()).log(Level.SEVERE, null, ex);
}
}
//For display the url image in a JPanel
private void DisplayImage(JPanel jp, String url) throws IOException, Exception {
try {
Image image=ImageIO.read(this.getClass().getResource(url));
ImageIcon imageicon=new ImageIcon(image);
JLabel label=new JLabel(imageicon);
jp.add(label);
} catch (IOException ex) {
throw new IOException();
} catch (Exception ex) {
throw new Exception();
}
}
public static void main(String args[]) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Sample.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Sample().setVisible(true);
}
});
}
// Variables declaration
private javax.swing.JPanel PanelImage;
}
private void DisplayImage(JPanel jp, String url)是我需要工作的，用于显示图像，来自JPanel jp
The private void DisplayImage(JPanel jp, String url) is what I need to work for display the image, from the url String url in the JPanel jp
推荐答案
我在Google中寻找代码段，最终得到了一个解决方案...并且所采用的模式与以前的注释所引用的模式相同. 给我解决方案的代码是:
Looking for pieces of code in Google I ended up with a solution... And was applying the same pattern that previous comments refer. The code that gave me the solution was:
label.setIcon(new javax.swing.ImageIcon(getClass().getResource("/resources/gray.png")))
然后，我制作了要实现的方法:
With that, I made then the method that I wanted to implement:
private static void DisplayImage(JPanel jp, String url) {
JLabel jl=new JLabel();
jl.setIcon(new javax.swing.ImageIcon(getClass().getResource(url)));
jp.add(jl);
}
也许这不是完美且最正确的解决方案，但对我来说却是完美的，这就是我想要的.
Maybe this is not the perfect and most-correct solution, but works perfect to my, that is what I want.
谢谢大家的回答和建议！
Thanks all for the answers and suggestions!
这篇关于如何在JPanel中显示图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
