我几个月前写了一篇文章MY POST

但是我想对我进行一些更改。现在我所有的代码都在Swingworker类中完成了。但是我想使用MVC方法并使用观察者模式来更新视图中的变量。

现在我有这样的东西

    public class CopyFrame extends JFrame {

        private JTextarea textArea;
        private JProgresbar progresbar;

        public CopyFrame(){
            progresbar = new JProgresbar
            textArea = new JTextarea();
            progresbar.setMaximum(100));
            /*in this method I added the components correctly*/
            addComponentsCorrecty();

            new Task().execute();
        }


        class Task extends Swingworker<Void,Void>{
            /*Dp this 10 times*/
            Files.Copy(source, destination);
            progresbar.setValue(progresbar.getValue + 10);

            String info = String.format("%s is completed", source)

        textArea.setText(textArea.getText + "\n" + info)
        }
    }


我想创建这样的东西

public class CopyFrame extends JFrame {

    private JTextarea textArea;
    private JProgresbar progresbar;

    public CopyFrame(){
        progresbar = new JProgresbar
        textArea = new JTextarea();
        progresbar.setMaximum(100));
        /*in this method I added the components correctly*/
        addComponentsCorrecty();

        Task task = new Task();
        task.addObserver(this);
        task.execute
    }

    @Override
    public void update(){
        progresbar.setValue(progresbar.getValue +10);
        textArea.setText(textArea.getText + "\n" + task.getInfo)
    }
}
class Task extends Swingworker<Void,Void> extends Observer{

        private String info;
        public Task(){
            doTask;
        }

        public void doTask(){
        /*Dp this 10 times*/
        Files.Copy(source, destination);
        info = String.format("%s is completed", source)
        setChanged();
        notifyObservers();
        }

        public String getInfo(){
            return info;
        }
}


我怎样才能做到这一点?因为我不能从两个班级扩展。
我想从另一个班级更新任务栏(任务)

我最好的选择是什么

最佳答案

SwingWorkerPropertyChangeListener的形式提供一种观察者模式。

这将提供有关状态更改(运行/完成/等)和进度更改的通知。

例如:


JProgressBar isn't progressing
How to use jProgress bar for ProcessBuilder process?
how to include a progress bar in a program of file transfer using sockets in java
Java - global, reusable loading dialog
JProgressBar won't update


厌倦了重写PropertyChangeListener的工作,我确实创建了一个简单的适配器,该适配器提供了更直接的事件通知

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.SwingWorker;

public class SwingWorkerListener<W extends SwingWorker> implements PropertyChangeListener {

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        W worker = (W) evt.getSource();
        switch (evt.getPropertyName()) {
            case "state":
                workerStateChanged(worker);
                switch (worker.getState()) {
                    case STARTED:
                        workerStarted(worker);
                        break;
                    case DONE:
                        workerDone(worker);
                        break;
                }
                break;
            case "progress":
                workerProgressUpdated(worker);
                break;
        }
    }

    protected void workerProgressUpdated(W worker) {
    }

    protected void workerStateChanged(W worker) {
    }

    protected void workerStarted(W worker) {
    }

    protected void workerDone(W worker) {
    }

}


这使我可以覆盖我实际感兴趣的方法,并减少了我必须继续编写的重复/锅炉代码的数量

记住,Swing基础的“侦听器”实际上是观察者模式的一种形式;)

关于java - JAVA:1类中具有Observer和Swingworker的JProgressbar&Files.copy,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/33136498/

10-12 03:03