在JPanel里显示图片,一般都通过Swing components 如JLabel或 JButton来显示 这是一个例子: import java.awt.GridLayout; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JFrame; import javax.swing.ImageIcon;/* * LabelDemo.java is a 1.4 application that needs one other file: * images/middle.gif */ public class LabelDemo extends JPanel { public LabelDemo() { super(new GridLayout(3,1)); //3 rows, 1 column JLabel label1, label2, label3; ImageIcon icon = createImageIcon("images/middle.gif", "a pretty but meaningless splat"); //Create the first label. label1 = new JLabel("Image and Text", icon, JLabel.CENTER); //Set the position of its text, relative to its icon: label1.setVerticalTextPosition(JLabel.BOTTOM); label1.setHorizontalTextPosition(JLabel.CENTER); //Create the other labels. label2 = new JLabel("Text-Only Label"); label3 = new JLabel(icon); //Create tool tips, for the heck of it. label1.setToolTipText("A label containing both image and text"); label2.setToolTipText("A label containing only text"); label3.setToolTipText("A label containing only an image"); //Add the labels. add(label1); add(label2); add(label3); } /** Returns an ImageIcon, or null if the path was invalid. */ protected static ImageIcon createImageIcon(String path, String description) { java.net.URL imgURL = LabelDemo.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL, description); } else { System.err.println("Couldn't find file: " + path); return null; } } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Make sure we have nice window decorations. JFrame.setDefaultLookAndFeelDecorated(true); //Create and set up the window. JFrame frame = new JFrame("LabelDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. LabelDemo newContentPane = new LabelDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }
这是一个例子:
import java.awt.GridLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.ImageIcon;/*
* LabelDemo.java is a 1.4 application that needs one other file:
* images/middle.gif
*/
public class LabelDemo extends JPanel {
public LabelDemo() {
super(new GridLayout(3,1)); //3 rows, 1 column
JLabel label1, label2, label3; ImageIcon icon = createImageIcon("images/middle.gif",
"a pretty but meaningless splat"); //Create the first label.
label1 = new JLabel("Image and Text",
icon,
JLabel.CENTER);
//Set the position of its text, relative to its icon:
label1.setVerticalTextPosition(JLabel.BOTTOM);
label1.setHorizontalTextPosition(JLabel.CENTER); //Create the other labels.
label2 = new JLabel("Text-Only Label");
label3 = new JLabel(icon); //Create tool tips, for the heck of it.
label1.setToolTipText("A label containing both image and text");
label2.setToolTipText("A label containing only text");
label3.setToolTipText("A label containing only an image"); //Add the labels.
add(label1);
add(label2);
add(label3);
} /** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path,
String description) {
java.net.URL imgURL = LabelDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL, description);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
} /**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Make sure we have nice window decorations.
JFrame.setDefaultLookAndFeelDecorated(true); //Create and set up the window.
JFrame frame = new JFrame("LabelDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane.
LabelDemo newContentPane = new LabelDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane); //Display the window.
frame.pack();
frame.setVisible(true);
} public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}