我制作了一个非常简单的代码来在此处显示它,我有一个按钮应该显示 JDialog 来检查进度状态,我正在使用延迟调用来完成 EDT 并且我的循环不在 run 方法中,那么为什么我的酒吧没有更新吗?
这是代码
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class JBarEx extends JFrame {
private JTextField progStatus = new JTextField("Undefined");
private JButton dialogBtn = new JButton("Show Progression dialog");
final JDialog dlg = new JDialog((JFrame) null, "prog Title", false);
final JProgressBar dpb = new JProgressBar(0, 100);
public JBarEx() {
JPanel pan = new JPanel();
dialogBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
showProgress();
}
});
progStatus.setEditable(false);
pan.add(progStatus);
pan.add(dialogBtn);
setContentPane(pan);
this.setSize(200, 100);
setVisible(true);
}
public void showProgress() {
dlg.add(BorderLayout.CENTER, dpb);
dlg.add(BorderLayout.NORTH, new JLabel("prog message"));
dlg.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dlg.setSize(300, 75);
dlg.setLocationRelativeTo(null);
dlg.setVisible(true);
for (int i = 0; i < 100; i++) {
final int ii = i;
try {
Thread.sleep(25);
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
updateBar(ii);
}
});
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void updateBar(int newValue) {
dpb.setValue(newValue);
}
public static void main(String[] args) {
JBarEx jbx = new JBarEx();
}
}
Your showProgress
方法正在事件调度线程的上下文中执行。 EDT 负责处理油漆请求等。这意味着只要您的for-loop
正在执行时,EDT 无法处理任何新的绘制请求(或处理invokeLater
事件),因为它阻塞了 EDT。
虽然有很多可能的方法来解决问题,但根据您的代码示例,最简单的方法是使用SwingWorker http://docs.oracle.com/javase/7/docs/api/javax/swing/SwingWorker.html.
它能够让您在后台线程中执行长时间运行的任务(释放 EDT),而且还允许您publishing
更新(如果需要),以便可以在 EDT 中处理它们,并提供方便的progress
通知。
例如...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
public class SwingWorkerProgress {
public static void main(String[] args) {
new SwingWorkerProgress();
}
public SwingWorkerProgress() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JProgressBar pbProgress;
private JButton start;
public TestPane() {
setBorder(new EmptyBorder(10, 10, 10, 10));
pbProgress = new JProgressBar();
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(4, 4, 4, 4);
gbc.gridx = 0;
gbc.gridy = 0;
add(pbProgress, gbc);
start = new JButton("Start");
gbc.gridy++;
add(start, gbc);
start.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
start.setEnabled(false);
ProgressWorker pw = new ProgressWorker();
pw.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
String name = evt.getPropertyName();
if (name.equals("progress")) {
int progress = (int) evt.getNewValue();
pbProgress.setValue(progress);
repaint();
} else if (name.equals("state")) {
SwingWorker.StateValue state = (SwingWorker.StateValue) evt.getNewValue();
switch (state) {
case DONE:
start.setEnabled(true);
break;
}
}
}
});
pw.execute();
}
});
}
}
public class ProgressWorker extends SwingWorker<Object, Object> {
@Override
protected Object doInBackground() throws Exception {
for (int i = 0; i < 100; i++) {
setProgress(i);
try {
Thread.sleep(25);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
}
}
查看Swing 中的并发 http://docs.oracle.com/javase/tutorial/uiswing/concurrency/更多细节
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