如何从文件夹中的图像将图标设置为 JLabel? [英] How to set Icon to a JLabel from an image from a folder?

问题描述

每当从 JComboBox 中选择一个项目时，我都试图从图像文件夹中将图标设置为 JLabel.JComboBox 中的项目名称和文件夹中的图像名称相同.因此，每当从 JComboBox 中选择一项时，应将相应的同名图像设置为 JLabel 的图标.我正在尝试做这样的事情.

I am trying to set an icon to a JLabel from a folder of images whenever an item is selected from a JComboBox. The name of items in the JComboBox and name of the images in the folder are same. So whenever an item is selected from the JComboBox, the corresponding image with the same name should be set as an icon to the JLabel. I am trying to do something like this.

private void cmb_movieselectPopupMenuWillBecomeInvisible(javax.swing.event.PopupMenuEvent evt){                                                             
        updateLabel(cmb_moviename.getSelectedItem().toString());
}





protected void updateLabel(String name) {
        ImageIcon icon = createImageIcon("C:\Users\xerof_000\Pictures\tmspictures\" + name + ".jpg");
        if(icon != null){
            Image img = icon.getImage(); 
            Image newimg = img.getScaledInstance(lbl_pic.getWidth(), lbl_pic.getHeight(),  java.awt.Image.SCALE_SMOOTH);
            icon = new ImageIcon(newimg);
            lbl_pic.setIcon(icon);
            lbl_pic.setText(null);
        }
        else{
            lbl_pic.setText("Image not found");
            lbl_pic.setIcon(null);
        }
    }





protected static ImageIcon createImageIcon(String path) {
        URL imgURL;
        imgURL = NowShowing.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            return null;
        }
    }

我认为问题出在 "C:Usersxerof_000Pictures mspictures" 我尝试使用 "C:/Users/xerof_000/Pictures/tmspictures/" 但即使这样也不起作用.无论我做什么，它都只会在 JLabel 上显示找不到图像".

I thought the problem is in "C:Usersxerof_000Pictures mspictures" I tried using "C:/Users/xerof_000/Pictures/tmspictures/" but even that did not work. And whatever I do it only shows "Image not found" on the JLabel.

推荐答案

这是我的目录结构:

                                packageexample
                                      |
                   -------------------------------------------
                   |                  |                      |
                build(folder)     src(folder)           manifest.txt
                   |                  |
             swing(package)       ComboExample.java
                   |
            imagetest(subpackage)
                   |
     ComboExample.class + related .class files

这是ComboExample.java文件的内容:

package swing.imagetest;    

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import javax.swing.*;
    
public class ComboExample {

    private String[] data = new String[]{
                                            "geek0",
                                            "geek1",
                                            "geek2",
                                            "geek3",
                                            "geek4"
                                        };
    private String MESSAGE = "No Image to display yet...";
    private JLabel imageLabel;
    private JComboBox cBox;
    private ActionListener comboActions = 
                            new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent ae) {
            JComboBox combo = (JComboBox) ae.getSource();
            ImageIcon image = new ImageIcon(
                        getClass().getResource(
                            "/" + combo.getSelectedItem() + ".gif"));
            if (image != null) {
                imageLabel.setIcon(image);
                imageLabel.setText("");
            } else {
                imageLabel.setText(MESSAGE);
            }
        }    
    };

    private void displayGUI() {
        JFrame frame = new JFrame("Combo Example");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        JPanel contentPane = new JPanel();
        imageLabel = new JLabel(MESSAGE, JLabel.CENTER);
        cBox = new JComboBox(data);
        cBox.addActionListener(comboActions);

        contentPane.add(imageLabel);
        contentPane.add(cBox);

        frame.setContentPane(contentPane);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String... args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new ComboExample().displayGUI();
            }
        });
    }
}

现在编译:

为了编译我这样做了:

Gagandeep Bali@LAPTOP ~/c/Mine/JAVA/J2SE/src/packageexample
$ javac -d build src/*.java

清单文件的内容:

JAR 文件创建:

Gagandeep Bali@LAPTOP ~/c/Mine/JAVA/J2SE/src/packageexample
$ cd build

Gagandeep Bali@LAPTOP ~/c/Mine/JAVA/J2SE/src/packageexample/build
$ jar -cfm imagecombo.jar ../manifest.txt *

现在将此 JAR 文件 带到任何包含这些图像的位置 (, , 、 和 )，然后运行JAR File，看看结果:-)

Now take this JAR File to any location having these images (, , , and ), and run the JAR File, and see the results :-)

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