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，我都会尝试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图像的名称相同。因此，无论何时从JComboBox中选择项目，都应将具有相同名称的相应图像设置为JLabel的图标。我正在尝试这样做。

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;
        }
    }

我认为问题在于C：\ Users\xerof_000\Pictures\tmspictures \我尝试使用C：/ Users / xerof_000 / Pictures / tmspictures /但即使这样也行不通。无论我做什么，它只在JLabel上显示Image not found。

I thought the problem is in "C:\Users\xerof_000\Pictures\tmspictures\" 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

这是的内容ComboExample.java 文件：

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：

要编译，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 *

现在将这个 JAR文件带到任何有这些图像的位置（，，，和），并运行 JAR文件，并查看结果： - ）

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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