我使用LayerUI的自定义子类创建了一些加载指示。
该列表是StringWorker子类的arrayArray。它的get方法是一个阻塞调用,所以我认为这就是问题,只是不知道如何解决。该层启动了一个计时器,据我所知,计时器是在自己的线程中执行的,因此阻塞获取不应被干扰。
loadingLayer.setVisible(true);
lockComponents();
for(int i = 0; i < list.size(); i++) {
try {
System.out.println("About to check "+i);
if(list.get(i).get() == null) {
}
} catch (InterruptedException e1) {
e1.printStackTrace();
} catch (ExecutionException e1) {
e1.printStackTrace();
}
}
unlockComponents();
loadingLayer.setVisible(false);
仅在完成所有这些代码之后,“ loadingLayer”才会出现。
LoadingLayerUI类:
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComponent;
import javax.swing.Timer;
import javax.swing.plaf.LayerUI;
public class LoadingLayerUI extends LayerUI<JComponent> implements ActionListener {
/**
*
*/
private static final long serialVersionUID = 827885062549399916L;
private boolean isShowing;
private Timer timer;
private String text;
@Override
public void paint(Graphics g, JComponent jc) {
super.paint(g, jc);
if(!isShowing)
return;
Graphics2D g2 = (Graphics2D) g.create();
int w = jc.getWidth();
int h = jc.getHeight();
g2.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, .7f));
g2.setPaint(Color.LIGHT_GRAY);
g2.fillRect(0, 0, w, h);
g2.setColor(Color.BLACK);
Font font = new Font("Sans-Serif",Font.BOLD, 20);
int width = g2.getFontMetrics(font).stringWidth("Loading");
g2.setFont(font);
if(text != null)
g2.drawString(text, (w-width)/2, h/2);
g2.dispose();
jc.repaint();
}
public void setVisible(boolean set) {
this.isShowing = set;
if(isShowing) {
timer = new Timer(200, this);
timer.start();
}
else {
timer.stop();
}
}
@Override
public void actionPerformed(ActionEvent e) {
if(!isShowing && timer.isRunning())
timer.stop();
if(text == null || text.equals("Downloading...")) {
text = "Downloading";
}
else
text += ".";
}
}
最佳答案
使用Swing时,应在单独的线程中执行长时间运行的任务。
这是本教程:http://docs.oracle.com/javase/tutorial/uiswing/concurrency/worker.html