Question

我开发了一个UI，我在其中将压缩文件的共享文件夹位置复制到我的系统中。对其执行一些操作并再次将其存储到机器位置，所有这些都是使用UI完成的。为此现在我想使用JProgressBar，但我不理解如何在线程的帮助下测量进度。我看到了JProgressBar的教程，但没有帮助。

我写的代码：

 import java.awt.Toolkit;
 import java.awt.event.*;
 import javax.swing.*;
 import java.beans.*;
 import java.util.Random;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 public class ProgressBar extends javax.swing.JFrame {
/**
 * Creates new form ProgressBar
 */


public ProgressBar() {

    initComponents();

}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jButton1 = new javax.swing.JButton();
    jProgressBar1 = new javax.swing.JProgressBar();
    jTextField1 = new javax.swing.JTextField();
    jScrollPane1 = new javax.swing.JScrollPane();
    jTextArea1 = new javax.swing.JTextArea();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jButton1.setText("ok");
    jButton1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton1ActionPerformed(evt);
        }
    });

    jProgressBar1.setStringPainted(true);

    jTextArea1.setColumns(20);
    jTextArea1.setRows(5);
    jScrollPane1.setViewportView(jTextArea1);

    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(68, 68, 68)
                    .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 119, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(44, 44, 44)
                    .addComponent(jButton1))
                .addGroup(layout.createSequentialGroup()
                    .addGap(150, 150, 150)
                    .addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, 167, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addContainerGap(298, Short.MAX_VALUE))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addGap(0, 0, Short.MAX_VALUE)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(99, 99, 99))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(41, 41, 41)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jButton1)
                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addGap(46, 46, 46)
            .addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, 27, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(48, 48, 48)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(91, Short.MAX_VALUE))
    );

    pack();
}// </editor-fold>                        

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:

    iterate();

}                                        

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    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(ProgressBar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(ProgressBar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(ProgressBar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(ProgressBar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new ProgressBar().setVisible(true);

    });
}

public void iterate()
    {
        int i = 0;
        while(i<=100){    
        jProgressBar1.setValue(i);    
        i=i+15;  

        try{Thread.sleep(700);}catch(Exception e){}    
    }    
  }

// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JProgressBar jProgressBar1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
private javax.swing.JTextField jTextField1;
// End of variables declaration                   
}

Answer 1

关键是你首先定义一个可以衡量的值来报告你的进度。

示例：您为上面列出的每个步骤提供15分，20分/百分比，每次完成此步骤，您都会增加进度。（您可以尝试预先测量执行时间，为不同的步骤提供不同的权重;或者您只是让每个步骤贡献相同的数量＆＃34;数量＆＃34;达到＆＃34; 100 ％＆＃34;最后）。

对于机制如何，那个教程肯定会有所描述！

这里的一个关键方面是线程。在您的示例中，主主题在进度条上调用setValue()。那样不行。当你回到oracle tutorial时，你会发现：

Task是javax.swing.SwingWorker的子类。 Task实例为ProgressBarDemo做了三件重要的事情：

实例在单独的线程中调用doInBackground。这是长时间运行的任务实际执行的地方。使用后台线程而不是事件派发线程可以防止用户界面在任务运行时冻结。

当后台任务完成后，实例将在事件派发线程中调用done方法。

实例维护绑定属性progress，该属性已更新以指示任务的进度。每次进度改变时都会调用propertyChange方法。

Answer 2

易。看看ProgressMonitorInputStream。

如何在java中测量JProgressBar的任务进度

2 个答案: