Question

public class PlayText extends Thread {

   private int duration;
   private String text;
   private PlayerScreen playerscrn; 

   public PlayText(String text, int duration) {
        this.duration = duration;
        this.text = text;
        this.playerscrn = (PlayerScreen)UiApplication.getUiApplication().getActiveScreen();
   }



    public void run() {
        synchronized(UiApplication.getEventLock()) {
            try{
                RichTextField text1player = new RichTextField(this.text, Field.NON_FOCUSABLE);
                playerscrn.add(text1player);
                playerscrn.invalidate();

                Thread.sleep(this.duration);

                RichTextField text2player = new RichTextField("hahhaha", Field.NON_FOCUSABLE);
                playerscrn.add(text2player);
                playerscrn.invalidate();

                Thread.sleep(1000);
                RichTextField text3player = new RichTextField("Done", Field.NON_FOCUSABLE);
                playerscrn.add(text3player);
                playerscrn.invalidate();

            }catch(Exception e){
             System.out.println("I HAVE AN ERROR");
            }   
        }
    }
}

使用上面的代码，我正在尝试创建一个小型文本播放器而是逐个获取所有文本标签，类似于
显示text1player
等待this.duration毫秒
显示text2player
等待1000毫秒
显示text3player
线程完成。

屏幕等待this.duration + 1000毫秒并立即显示所有标签。我尝试使用runnable并调用.invokeLater或.invokeAndWait，但我仍然得到相同的行为，即使我像上面那样使用synchronized变脏，它仍然不起作用。
有谁知道我如何一次显示每个标签？
谢谢！

Answer 1

尝试在sleep语句之间移动同步...也许它没有显示，因为你已经获得了锁定，并且在你睡觉时UI线程无法更新。

在线程处于休眠状态时，您是否在UI中看到延迟或无响应？试试这种方式：

public class PlayText extends Thread {

   private int duration;
   private String text;
   private PlayerScreen playerscrn; 

    public PlayText(String text, int duration) {
        this.duration = duration;
        this.text = text;
        this.playerscrn = (PlayerScreen)UiApplication.getUiApplication().getActiveScreen();
    }

    private void displayTextLabel(string textToDisplay){
        synchronized(UiApplication.getEventLock()) {
            playerscrn.add(new RichTextField(textToDisplay, Field.NON_FOCUSABLE));
            playerscrn.invalidate();
        }
    }

    public void run() {

            try{

                displayTextLabel(this.text);
                Thread.sleep(this.duration);

                displayTextLabel("hahhaha");
                Thread.sleep(1000);

                displayTextLabel("Done");

            }catch(Exception e){
             System.out.println("I HAVE AN ERROR");
            }   
        }
    }
}

如何从线程更新blackberry UI项？

1 个答案: