请问java的JLabel上的图片如何刷新？

2025-02-20 14:17:01

推荐回答（5个）

回答1：

　　java jlabel 图片的更新及清空
Java jlabel 里显示衣服图片根据jcombobox的内容实现不了更新，
还有我想把jlabel的图片清空怎么实现！
jLabel.setIcon(null),编译出错。
麻烦大家指点一下

------解决方案--------------------
我运行label.setIcon(null)没有问题，给你一个例子，运行的时候，需要在工程目录下有images目录，该目录下加上1.jpg 2.jpg …… 8.jpg这样八个图片
Java codeimport java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;

import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;

public class ImageRandomAccess2 implements ActionListener {
final static int NUM_IMAGES = 8;//显示的图片总数

final static int START_INDEX = 3;//初始化的时候默认显示的图片

ImageIcon[] images = new ImageIcon[NUM_IMAGES];//初始化数组

JPanel mainPanel, selectPanel, displayPanel;//三个面板

JLabel selectLabel=null;

JComboBox combobox=null;//控制显示有哪些图片，非随即滚动

JButton controlBtn=null;

JLabel imageIconLabel = null;

// Constructor
public ImageRandomAccess2() {
// Create the phase selection and display panels.
selectPanel = new JPanel();
displayPanel = new JPanel();

// Add various widgets to the sub panels.
addWidgets();

// Create the main panel to contain the two sub panels.
mainPanel = new JPanel();
mainPanel.setLayout(new GridLayout(2, 1, 5, 5));
mainPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));

// Add the select and display panels to the main panel.
mainPanel.add(selectPanel);
mainPanel.add(displayPanel);
}

// Create and the widgets to select and display the images of peoples.
private void addWidgets() {
// Get the images and put them into an array of ImageIcon.

for (int i = 0; i < NUM_IMAGES; i++) {
String imageName = "images/" + (i + 1) + ".jpg";
System.out.println("getting image: " + imageName);
// URL iconURL = ClassLoader.getSystemResource(imageName);

ImageIcon icon = new ImageIcon(imageName);
images[i] = icon;
}

// Create label for displaying images and put a border around
// it.
imageIconLabel = new JLabel();
imageIconLabel.setHorizontalAlignment(JLabel.CENTER);
imageIconLabel.setVerticalAlignment(JLabel.CENTER);
imageIconLabel.setVerticalTextPosition(JLabel.CENTER);
imageIconLabel.setHorizontalTextPosition(JLabel.CENTER);
imageIconLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createLoweredBevelBorder(),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));

imageIconLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createEmptyBorder(0, 0, 10, 0),
imageIconLabel.getBorder()));

controlBtn=new JButton("无图片");
selectLabel=new JLabel("选择图片");

combobox=new JComboBox();

for(int i=0;i combobox.addItem(i);
}
selectLabel.setLabelFor(combobox);

// Display the first image.
imageIconLabel.setIcon(images[START_INDEX]);
imageIconLabel.setText("");

// Add border around the select panel.
selectPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Select Phase"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));

// Add border around the display panel.
displayPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Display Phase"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));

// Add control button to select panel and image label to
// displayPanel.
selectPanel.add(selectLabel);
selectPanel.add(combobox);
selectPanel.add(controlBtn);
displayPanel.add(imageIconLabel);

// Listen to events from control button.
// controlBtn.addActionListener(this);
combobox.addActionListener(this);
controlBtn.addActionListener(this);
}

boolean run = false;

// Implementation of ActionListener interface.
public void actionPerformed(ActionEvent event) {
if(event.getSource()==combobox){
int imageIndex=combobox.getSelectedIndex();
imageIconLabel.setIcon(images[imageIndex]);
}
if(event.getSource()==controlBtn){
System.out.println("------------");
imageIconLabel.setIcon(null);
// imageIconLabel.setIcon(new ImageIcon());
}

}

// main method
public static void main(String[] args) {
// create a new instance of ImageRandomAccess
ImageRandomAccess2 phases = new ImageRandomAccess2();

// Create a frame and container for the panels.
JFrame mainFrame = new JFrame("ImangeRandomAccess");

// Set the look and feel.
try {
UIManager.setLookAndFeel(UIManager
.getCrossPlatformLookAndFeelClassName());
} catch (Exception e) {
}

mainFrame.setContentPane(phases.mainPanel);

// Exit when the window is closed.
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

// Show the converter.
mainFrame.pack();
mainFrame.setLocationRelativeTo(null);
mainFrame.setVisible(true);
}
}

回答2：

用setIcon。API这里找到一个中文的http://www.cjsdn.net/Doc/JDK50/javax/swing/JLabel.html#setIcon(javax.swing.Icon)
icon参数新建一个ImageIcon，也就是图片图标。
更改图标后，下一次用户看到它之前就会刷新了。

回答3：

如果下面的方法都用完了，还是不行
background = new ImageIcon("D://ClientData//result.jpg");
resultLabel.setIcon(background);
resultLabel.repaint();
resultLabel.updateUI();
resultLabel.setVisible(true);

试一下这种方法：
String path = "D://ClientData//result.jpg";
Icon icon;
try {
icon = new ImageIcon(ImageIO.read(new File(path)));
resultLabel.setIcon(icon);
} catch (IOException e) {
e.printStackTrace();
}

回答4：

可以做个线程定时刷新

回答5：

需要调用重绘的方法

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