请帮忙。该代码不起作用。进度条已创建，其中显示 0% 就这样。我对 java 不太了解。我正在寻求帮助。
原始代码:
jProgressBar1.setName("");
jProgressBar1.setValue(0);
jProgressBar1.setStringPainted(true);
jProgressBar1.addContainerListener(new java.awt.event.ContainerAdapter() {
public void componentAdded(java.awt.event.ContainerEvent evt) {
jProgressBar1ComponentAdded(evt);
}
});
private void jProgressBar1ComponentAdded(java.awt.event.ContainerEvent evt) {
Task tk = new Task();
tk.run();
}
class Task extends Thread {
public Task(){}
public void run(){
for(int i =0; i<= 100; i++){
final int progress = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
jProgressBar1.setValue(progress);
}
});
}}}
最新代码:
import java.awt.event.ContainerAdapter;
import java.awt.event.ContainerEvent;
import javax.swing.*;
public class ini extends JFrame {
public ini() {
initComponents();
}
private void initComponents() {
setResizable(false);
jLabel1 = new JLabel();
jProgressBar1 = new JProgressBar(0,100);
jProgressBar1.addContainerListener(new ContainerAdapter() {
@Override
public void componentAdded(ContainerEvent e) {
if (jProgressBar1 == e.getChild()) {
System.out.println("progressBar!");
new Thread(new Task()).start();
}
}
});
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Criminal Records");
jLabel1.setFont(new java.awt.Font("Tahoma", 1, 24)); // NOI18N
jLabel1.setText("Criminal Records");
jProgressBar1.setName("");
jProgressBar1.setValue(0);
jProgressBar1.setStringPainted(true);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(204, 204, 204)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 254, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(215, 215, 215)
.addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, 176, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(242, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(312, 312, 312)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 58, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(348, Short.MAX_VALUE))
);
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(ini.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ini.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ini.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ini.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new ini().setVisible(true);
}
});
}
private class Task implements Runnable {
private static final long SLEEP_TIME = 100;
@Override
public void run() {
for (int i = 0; i <= 100; i++) {
final int progress = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
jProgressBar1.setValue(progress);
}
});
try {
Thread.sleep(SLEEP_TIME);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
private javax.swing.JLabel jLabel1;
private javax.swing.JProgressBar jProgressBar1;
}
最佳答案
我发现您使用线程存在一个主要问题和一个小问题:
- 小问题:您应该实现 Runnable，而不是扩展 Thread，因为这将线程运行的代码与线程分开，遵循单一责任规则，并为线程运行的代码提供了更大的灵 active ，因为现在它如果需要的话可以扩展其他类。
- 启动线程时，请对其调用
.start()，而不是.run()，因为后者将保证不会创建后台线程.
至于您的另一个问题，即使用 ContainerListener 的问题，我等待您对问题的澄清，以及您创建和发布您的 minimal code example program供我们审查、测试并可能修复。
<小时/>编辑
根据您的评论，
I want to show a progress-bar in a frame which show 0-100%. I created the frame and added the progress bar. But it shows only 0% and not moving.
同样，您还有一些线程问题需要修复。您还需要在其中放置一个 Thread.sleep 来减慢 for 循环的速度。否则，即使使用适当的线程，您也不会看到进展。
I want to invoke the function when progressbar is added to the frame.
您正在将 ContainerListener 添加到 JProgressBar，但这不起作用，因为您没有向进度条添加任何内容。相反，您需要将监听器添加到保存进度条的容器中。但即便如此，这可能不是开始这一过程的好方法。但让我看看我能做什么......请稍等。
<小时/>例如，
import java.awt.event.ContainerAdapter;
import java.awt.event.ContainerEvent;
import javax.swing.*;
public class JProgressExample extends JPanel {
private JProgressBar jProgressBar1 = new JProgressBar(0, 100);
public JProgressExample() {
addContainerListener(new ContainerAdapter() {
@Override
public void componentAdded(ContainerEvent e) {
if (jProgressBar1 == e.getChild()) {
System.out.println("progressBar!");
new Thread(new Task()).start();
}
}
});
jProgressBar1.setName("");
jProgressBar1.setValue(0);
jProgressBar1.setStringPainted(true);
add(jProgressBar1);
}
private class Task implements Runnable {
private static final long SLEEP_TIME = 100;
@Override
public void run() {
for (int i = 0; i <= 100; i++) {
final int progress = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
jProgressBar1.setValue(progress);
}
});
try {
Thread.sleep(SLEEP_TIME);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
private static void createAndShowGui() {
JProgressExample mainPanel = new JProgressExample();
JFrame frame = new JFrame("JProgressExample");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
关于java - 为 ProgressBar Java 添加容器监听器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25822901/