JProgress Bar不確定模式不更新

Question

我有一個JNI函數，可能需要一段時間才能完成，並且我想要一個JProgress欄處於不確定模式，並在完成該函數時運行。我已閱讀了Oracle提供的教程，但其教程的性質似乎並沒有幫助我理解如何去做。我意識到我應該在後臺線程中運行這個函數，但我不太確定如何去做。

這是相關的代碼。我有一個按鈕（runButton），將調用函數，mainCpp（），按下時：

public class Foo extends javax.swing.JFrame 
         implements ActionListener, 
            PropertyChangeListener{ 

    @Override 
    public void actionPerformed(ActionEvent ae){ 
     //Don't know what goes here, I don't think it is necessary though because I do not intend to use a determinate progress bar 
    } 

    @Override 
    public void propertyChange(PropertyChangeEvent pce){ 
     //I don't intend on using an determinate progress bar, so I also do not think this is necassary 
    } 

class Task extends SwingWorker<Void, Void>{ 

    @Override 
    public Void doInBackground{ 
     Foo t = new Foo(); 
     t.mainCpp(); 

     System.out.println("Done..."); 
    } 
    return null; 
} 

/*JNI Function Declaration*/ 
public native int mainCpp(); //The original function takes arguments, but I have ommitted them for simplicity. If they are part of the problem, I can put them back in. 

...//some codes about GUI 

private void runButtonActionPerformed(java.awt.event.ActionEvent evt) { 

    ProgressBar.setIndeterminate(true); 
    Task task = new Task(); 
    task.execute();  
    ProgressBar.setIndeterminate(false); 

} 


/*Declarations*/ 
private javax.swing.JButton runButton; 
} 

任何幫助，將不勝感激。

編輯：編輯嘗試做什麼kiheru建議，但仍然無法正常工作。

Answer 1

假設你有一個這樣的的SwingWorker：

class Task extends SwingWorker<Void, Void>{ 
    @Override 
    public Void doInBackground() { 
     // I'm not sure of the code snippets if you are already in a 
     // Foo instance; if this is internal to Foo then you obviously do 
     // not need to create another instance, but just call mainCpp(). 
     Foo t = new Foo(); 
     t.mainCpp(); 
     return null; 
    } 

    @Override 
    public void done() 
     // Stop progress bar, etc 
     ... 
    } 
} 

你可以保留一個實例中包含的對象的字段，然後用它的工作是這樣的：

private void runButtonActionPerformed(java.awt.event.ActionEvent evt) { 
    // Start progress bar, disable the button, etc. 
    ... 
    // Task task has been created earlier, maybe in the constructor 
    task.execute(); 
} 

，或者你可以創建一個工作人員：

private void runButtonActionPerformed(java.awt.event.ActionEvent evt) { 
    // Start progress bar, disable the button, etc. 
    ... 
    new Task().execute(); 
}