Question

我有一个JNI函数可能需要一段时间才能完成，我希望在完成函数时运行不确定模式的JProgress栏。我已经阅读了Oracle提供的教程，但是他们的教程的性质似乎并没有帮助我理解如何做到这一点。我意识到我应该在后台线程中运行这个函数，但我不太清楚如何去做。

这是相关代码。我有一个按钮（runButton），当按下时会调用函数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：编辑试图做kiheru建议，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
        ...
    }
}

您可以将实例保存在包含对象的字段中，然后使用它将如下所示：

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();
}

，或者您可以创建一个工作人员：

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

JProgressBar不确定模式不更新

1 个答案: