JProgress Bar Indeterminate 模式未更新

Question

我有一个 JNI 函数可能需要一段时间才能完成，我希望在完成该函数时运行一个处于不确定模式的 JProgress 栏。我已经阅读了 Oracle 提供的教程，但他们教程的性质似乎并不能帮助我理解如何去做。我意识到我应该在后台线程中运行这个函数，但我不太确定该怎么做。

这里是相关代码。我有一个按钮（runButton），按下时会调用函数 mainCpp()：

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;
}

任何帮助将不胜感激。

编辑：编辑以尝试执行 kiheru 建议的操作，但仍然无法正常工作。

Answer 1

假设你有一个像这样的 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
        ...
    }
}

您可以在包含对象的字段中保留一个实例，然后使用它会像这样工作：

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();
}

，或者你可以就地创建一个worker：

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