JFrame popup显示内容

Question

我有ClassA做了一些处理，我希望它创建一个弹出的Jframe ClassB，它显示了ClassA计算的一些统计信息。所以我做了这样的事情：

public class MainMenu extends javax.swing.JFrame { 

public MainMenu() { 
    initComponents(); 
} 

private void initComponents() { 

    calculateButton = new javax.swing.JButton(); 

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

    calculateButton.setText("Calculate"); 
    calculateButton.addActionListener(new java.awt.event.ActionListener() { 
     public void actionPerformed(java.awt.event.ActionEvent evt) { 
      calculateButtonActionPerformed(evt); 
     } 
    }); 

    pack(); 
}    

private void calculateButtonActionPerformed(java.awt.event.ActionEvent evt) {             
    new ClassA().calculate(); 
} 
public static void main(String args[]) { 

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




public class ClassA { 
private int i; 
private ClassB classB; 
public ClassA(){ 
    i = 3000; 
    classB = new ClassB(); 
    classB.setVisible(true); 


} 

public void calculate(){ 
    int percentComplete; 
    for (int j = 0 ; j<i ; j++){ 
     for (int x = 0; x<100000 ; x++) 
      for (int y = 0; y<100000 ; y++) 
       for (int z = 0; z<100000 ; z++); 
     percentComplete = (int) (100 * (float)j/ (float) i); 
     System.out.println(" "+percentComplete); 
     classB.setProgress(percentComplete); 
    } 
} 

}

public class ClassB extends javax.swing.JFrame { 

public ClassB() { 
    initComponents(); 
} 

private void initComponents() { 

    jPanel1 = new javax.swing.JPanel(); 
    jProgressBar1 = new javax.swing.JProgressBar(); 

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

    jProgressBar1.setStringPainted(true); 
    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1); 
    jPanel1.setLayout(jPanel1Layout); 
    jPanel1Layout.setHorizontalGroup(
     jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(jPanel1Layout.createSequentialGroup() 
      .addComponent(jProgressBar1, javax.swing.GroupLayout.DEFAULT_SIZE, 370, Short.MAX_VALUE) 
      .addContainerGap()) 
    ); 
    jPanel1Layout.setVerticalGroup(
     jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(jPanel1Layout.createSequentialGroup() 
      .addGap(39, 39, 39) 
      .addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addContainerGap(52, 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() 
      .addContainerGap() 
      .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) 
      .addContainerGap()) 
    ); 
    layout.setVerticalGroup(
     layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(layout.createSequentialGroup() 
      .addContainerGap() 
      .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addContainerGap(181, Short.MAX_VALUE)) 
    ); 

    pack(); 
} 

public void setProgress(int x){ 
    jProgressBar1.setValue (x); 
} 


private javax.swing.JPanel jPanel1; 
private javax.swing.JProgressBar jProgressBar1; 

}

我现在面临的问题是，ClassB的的JFrame中显示为一个空的窗口，而且不显示任何东西直到ClassA的所有过程/计算都完成。然后显示它的内容，但使用ClassA数据的最新更新。 任何想法或解决方案？

Answer 1

您没有显示如何调用那些进行各种计算的ClassA的方法。我只能猜测你在一个事件调度线程中调用了所有这些函数（细节请参见The Event Dispatch Thread），而且在ClassA完成其处理之前，Java不能渲染任何内容。

如果是这种情况，您应该在其他线程中运行这些计算。这样做的最方便的方式是using SwingWorker。