我开发了一个小应用程序来跟踪我的日常工作活动，这个工具包含两个类：
我的目标是创建一个ProgressBar来更新执行的状态，下面给出了使用的逻辑，
注意：在将面板添加到JFrame后调用setVisible（true）。
Executor.java
public void executeTask ()
{
/* Create and display the form */
progress = new UIProgress();
progress.prepareGUI();
progress.updateProgress (10);
getWorkedItems ();
//progress.pack ();
progress.updateProgress (30);
getWorkedTickets ();
progress.updateProgress (50);
getRemainTickets ();
progress.updateProgress (70);
jf.postTriagedTicketDetailsDaily();
...
}
UIProgress.java
public class UIProgress extends javax.swing.JFrame {
public UIProgress() {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
initComponents();
}
private void initComponents() {
panelHeading = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
progress_cntrl = new javax.swing.JProgressBar();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
panelHeading.setBackground(new java.awt.Color(204, 204, 204));
panelHeading.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
panelHeading.setDebugGraphicsOptions(javax.swing.DebugGraphics.NONE_OPTION);
panelHeading.setOpaque(false);
jLabel1.setBackground(new java.awt.Color(0, 0, 0));
jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/devtriagerepot_daily/Background-20.jpeg"))); // NOI18N
javax.swing.GroupLayout panelHeadingLayout = new javax.swing.GroupLayout(panelHeading);
panelHeading.setLayout(panelHeadingLayout);
panelHeadingLayout.setHorizontalGroup(
panelHeadingLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, panelHeadingLayout.createSequentialGroup()
.addContainerGap(29, Short.MAX_VALUE)
.addComponent(progress_cntrl, javax.swing.GroupLayout.PREFERRED_SIZE, 651, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(27, 27, 27))
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 0, Short.MAX_VALUE)
);
panelHeadingLayout.setVerticalGroup(
panelHeadingLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(panelHeadingLayout.createSequentialGroup()
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 147, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(26, 26, 26)
.addComponent(progress_cntrl, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 31, 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(layout.createSequentialGroup()
.addComponent(panelHeading, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 4, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(panelHeading, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
);
getAccessibleContext().setAccessibleParent(this);
pack();
}
public void prepareGUI ()
{
progress_cntrl.setMaximum(120);
progress_cntrl.setStringPainted(true);
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int) ((dimension.getWidth() - this.getWidth()) / 2);
int y = (int) ((dimension.getHeight() - this.getHeight()) / 2);
this.setLocation(x, y);
pack ();
setVisible(true);
}
public void updateProgress (int val)
{
progress_cntrl.update(progress_cntrl.getGraphics());
progress_cntrl.setValue(val);
}
答案 0 :(得分：2)
关键在于这些方法：
getWorkedItems ();
getWorkedTickets ();
getRemainTickets ();
如果他们花费任何时间执行，那么在Swing事件线程上调用它们将阻塞线程并完全冻结GUI，使其无法正确绘制。解决方案是在后台线程中调用任何长时间运行的方法，例如SwingWorker的doInBackground()方法，并仅在Swing事件线程上进行Swing调用。同样，SwingWorker可以很好地工作，事实上它有自己的＆＃34;绑定＆＃34;可以使用的进度属性。在worker中只需调用setProgress(value)，其中value是你的int，从0到100.然后将PropertyChangeListener附加到worker，以便在更新progress属性时通知GUI这些更改。
警告：确保监听工作人员完成其运行，以便您可以在工作程序上调用get()，因为这会让您陷入并响应在运行期间可能已调用的任何异常。
例如，您的代码可能类似于：
public void executeTask() {
progress = new UIProgress();
progress.prepareGUI();
final SwingWorker<Void, Void> myWorker = new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() throws Exception {
// progress.updateProgress (10);
setProgress(10); // sets the worker's "bound" progress property
getWorkedItems();
setProgress(30);
getWorkedTickets();
setProgress(50);
getRemainTickets();
setProgress(70);
// ... only further background work goes here
// no direct Swing calls
return null;
}
};
myWorker.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if ("progress".equals(evt.getPropertyName())) {
// if the progress property has been changed
// get its value and use it to update the GUI
progress.updateProgress((int) evt.getNewValue());
} else if (SwingWorker.StateValue.DONE == evt.getNewValue()) {
// worker is done then here notify the GUI
// perhaps call:
// jf.postTriagedTicketDetailsDaily();
// call get() on worker to catch and handle exceptions
try {
myWorker.get();
} catch (InterruptedException | ExecutionException e) {
// TODO handle the excpetions here
e.printStackTrace();
}
}
}
});
myWorker.execute();
}
注意：代码未经过测试。
如果这不能解决您的问题，那么您可能需要创建并发布sscce或minimal example program/mcve，其中您将代码压缩到仍然编译和运行的最小位，没有外部依赖（例如需要链接到数据库或图像），没有额外的代码与您的问题无关，但仍然证明您的问题。
例如，这个小程序在工作GUI中演示了上述代码：
import java.awt.*;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import javax.swing.*;
public class TestWorker {
private UIProgress progress;
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
new TestWorker().executeTask();
});
}
public void executeTask() {
progress = new UIProgress();
progress.prepareGUI();
final SwingWorker<Void, Void> myWorker = new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() throws Exception {
// progress.updateProgress (10);
setProgress(10); // sets the worker's "bound" progress property
getWorkedItems();
setProgress(30);
getWorkedTickets();
setProgress(50);
getRemainTickets();
setProgress(70);
TimeUnit.SECONDS.sleep(2);
// ... only further background work goes here
// no direct Swing calls
return null;
}
};
myWorker.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if ("progress".equals(evt.getPropertyName())) {
// if the progress property has been changed
// get its value and use it to update the GUI
progress.updateProgress((int) evt.getNewValue());
} else if (SwingWorker.StateValue.DONE == evt.getNewValue()) {
// worker is done then here notify the GUI
progress.updateProgress(100);
// perhaps call:
// jf.postTriagedTicketDetailsDaily();
// call get() on worker to catch and handle exceptions
try {
myWorker.get();
} catch (InterruptedException | ExecutionException e) {
// TODO handle the exceptions here
e.printStackTrace();
}
}
}
});
myWorker.execute();
}
// dummy methods just to demonstrate long-running code
private void getRemainTickets() {
mySleep(3); // emulate long-running code
}
private void getWorkedTickets() {
mySleep(4);
}
private void getWorkedItems() {
mySleep(2);
}
private void mySleep(int seconds) {
try {
TimeUnit.SECONDS.sleep(seconds);
} catch (InterruptedException e) {}
}
@SuppressWarnings("serial")
private class UIProgress extends JPanel {
private static final int PREF_W = 400;
private static final int PREF_H = 100;
private JProgressBar progressBar = new JProgressBar(0, 100);
private JLabel statusLabel = new JLabel(" ");
public UIProgress() {
JPanel statusPanel = new JPanel(new FlowLayout(FlowLayout.LEADING, 0, 0));
statusPanel.add(new JLabel("Status:"));
statusPanel.add(Box.createHorizontalStrut(4));
statusPanel.add(statusLabel);
setLayout(new BorderLayout());
setBorder(BorderFactory.createEmptyBorder(3, 3, 3, 3));
add(statusPanel, BorderLayout.PAGE_START);
add(progressBar, BorderLayout.PAGE_END);
}
public void prepareGUI() {
JFrame frame = new JFrame("UI Progress");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(this);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
public void updateProgress(int prog) {
String text = String.format("Current Progress is %d%%", prog);
statusLabel.setText(text);
progressBar.setValue(prog);
}
}
}