如何从文件夹中的图像将图标设置为JLabel？

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。 我想做这样的事情。

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; } } 

我认为问题出现在“C：\ Users \ xerof_000 \ Pictures \ tmspictures \”中我尝试使用“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”。

Answer 1

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，我做了这个：

 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 File带到具有这些图像的任何位置（ ， ， ， 和 ），并运行JAR File ，并查看结果:-)

Answer 2

如“ 如何使用图标”中所述， getResource()方法需要在程序的JAR文件中查找图像。 您需要将图像移动到项目中。 IconDemo就是一个完整的例子。

Answer 3

由于你使用jLabel，你可以简单地使用HTML标签，只需用开始标签文本，并在标签中使用HTML标签，在旅游案例中：你可以使用这个取代 ： ）。 带着微笑图标。

Answer 4

  /* Create an Image File whose size is 700 x 472 (pixels) in any image editor. Here Image was created using MS - Paint. Make sure that the Image File and the main file are in the same folder. The size of the JFrame should be set to 700 x 472 (pixels) in the program. Set the JLabel's IconImage. Add the JLabel to the JFrame. Set JFrame properties. Display JFrame. ------------------------------------------------------------------------------ label.setIcon(getClass().getResources(String name)); label.setIcon(new ImageIcon(String file)); These 2 methods, don't always work with us. So, we create a method "getImageIcon(File f)" that returns a new ImageIcon Object, everytime a new File Object is passed to it. */ import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JButton; import java.awt.Image; import javax.imageio.ImageIO; import java.io.File; import java.io.IOException; import javax.swing.ImageIcon; import static javax.swing.WindowConstants.*; public class ImageDemo { JFrame frame = new JFrame(); //initialized JLabel label = new JLabel(); //initialized JButton button = new JButton(); //initialized ImageIcon ii; //not initialized public void displayImage() { //Layout Type: Null Layout. label.setIcon(getImageIcon(new File("print.png"))); button.setBounds(150,150,358,66); //Note that sizes of the Image and Button are same. button.setIcon(getImageIcon(new File("Button.png"))); label.add(button); //add the button to the label frame.add(label); frame.setBounds(300, 50, 700, 472); //(300 x 50 = HorizontalAlignment x VerticalAlignment) //(700 x 472 = Width x Height) frame.setTitle("Image Demo"); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); //WindowConstants.EXIT_ON_CLOSE frame.setVisible(true); } public ImageIcon getImageIcon(File f) { try { Image im = ImageIO.read(f); ii = new ImageIcon(im); } catch(IOException i) { i.printStackTrace(); } finally { return ii; } } public static void main(String[] args) { ImageDemo id = new ImageDemo(); id.displayImage(); } }