首先，我在整個背景上應用了面板，然后在此處創建了一個標簽來設定影像。 JFrame圖片
我看到有很多與空指標例外相關的問題和答案，但沒有人為我作業。ImageIcon 無法獲取影像。我什至嘗試通過創建一個檔案夾并給出路徑，但錯誤仍然相同。Netbeans: 12.5 jdk:8 請幫助我。提前致謝。
package com.mycompany.supershop;
import java.awt.Image;
import java.awt.Toolkit;
import javax.print.DocFlavor.URL;
import javax.swing.ImageIcon;
public class add_image extends javax.swing.JFrame {
public add_image() {
initComponents();
ImageIcon img= new ImageIcon(Toolkit.getDefaultToolkit().getImage(getClass().getResource("shop_removebg.png")));
Image img1=img.getImage();
Image img2 = img1.getScaledInstance(jLabel1.getWidth(),jLabel1.getHeight(),Image.SCALE_SMOOTH);
ImageIcon i=new ImageIcon(img2);
jLabel1.setIcon(i);
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("jLabel1");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(87, 87, 87)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 112, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(303, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(33, 33, 33)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(158, 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(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
pack();
}
public static void main(String args[]) {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(add_image.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(add_image.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(add_image.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(add_image.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new add_image().setVisible(true);
}
});
}
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
}
錯誤顯示，
> Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at sun.awt.SunToolkit.imageCached(SunToolkit.java:899)
at sun.lwawt.macosx.LWCToolkit.getImage(LWCToolkit.java:549)
at com.mycompany.supershop.add_image.<init>(add_image.java:24)
at com.mycompany.supershop.add_image$1.run(add_image.java:107)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
------------------------------------------------------------------------
問題出在這一行，
ImageIcon img= new ImageIcon(Toolkit.getDefaultToolkit().getImage(getClass().getResource("shop_removebg.png")));
應要求顯示錯誤的影像：
圖片1 圖片2 圖片3 圖片4
uj5u.com熱心網友回復：
給定專案結構，影像的有效路徑字串將是：
"/com/mycompany/supershop/shop_removebg.png"
始終使用/前綴來指示從類路徑的根搜索。
轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/363040.html