Question

我有一个应用程序，它显示一个带有应用横幅和标题+图像+详细信息（RichTextField）的新闻屏幕以及屏幕底部的广告横幅，所以一旦我向下滚动阅读细节我无法回来在顶部..它停在屏幕中间，就像你在这些图片中看到的那样..我不知道为什么......当你在触摸屏设备上使用触摸时，它的效果非常好

before scrolling

after scrolling back with the trackwheel

这是我的屏幕代码...请帮忙

public class DetailsScreen_en extends MainScreen {

AppManager appManager;
private Detailsbean_en bean;
private AppManager manager;
private BitmapField bitmapField;
private LabelField titleField;
private LabelField dateField;
private RichTextField articleField;
private Bitmap bitmap;
private BitmapField bar;
private HorizontalFieldManager hfm;
Adsbean[] adsBean;
BitmapField ad;
VerticalFieldManager otherStuff;
VerticalFieldManager vvv;
Timer time;
TimerTask task;
private HorizontalFieldManager admanager;
private int adCounter = 0;
private boolean status;
private int tour;

public DetailsScreen_en(boolean status, int tour) {
    appManager = AppManager.getInstance();
    adsBean = appManager.getAdsBean();
    Locale.setDefault(Locale.get(Locale.LOCALE_en));
    // ScreenOne.showLoadingScreen();
    this.status = status;
    this.tour = tour;
    XYEdges padding = new XYEdges(10, 10, 10, 10);
    HTMLParser parser = new HTMLParser();

    vvv = new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL
            | Field.FOCUSABLE) {
        protected void sublayout(int maxWidth, int maxHeight) {
            // TODO Auto-generated method stub
            super.sublayout(maxWidth, maxHeight);
            setExtent(maxWidth, Display.getHeight() - ad.getHeight());
        }
    };
    hfm = new HorizontalFieldManager();
    bar = new BitmapField(DesignSizes.FanClubBar(), Field.FIELD_HCENTER
            | Field.NON_FOCUSABLE | Field.READONLY);
    hfm.add(bar);
    vvv.add(hfm);
    hfm = new HorizontalFieldManager();
    manager = AppManager.getInstance();
    bean = manager.getBean_en();
    // System.out.println("DATE: "+ bean.getNewsDate() );

    // another try ...
    Date _date;
    Calendar _cal = Calendar.getInstance();
    _cal.set(Calendar.YEAR,
            Integer.parseInt(bean.getNewsDate().substring(0, 4)));
    _cal.set(Calendar.MONTH,
            Integer.parseInt(bean.getNewsDate().substring(5, 7)) - 1);
    _cal.set(Calendar.DAY_OF_MONTH,
            Integer.parseInt(bean.getNewsDate().substring(8, 10)));

    _date = _cal.getTime();

    DateFormat dff = new SimpleDateFormat("dd MMMM yyyy");
    String datedatedate = dff.formatLocal(_date.getTime());
    dateField = new LabelField(datedatedate);
    dateField.setPadding(padding);
    titleField = new LabelField(bean.getNewsTitle(), Field.FIELD_LEFT) {
        protected void paint(Graphics graphics) {
            // TODO Auto-generated method stub
            graphics.setColor(Color.ORANGE);
            super.paint(graphics);
        }

    };
    titleField.setPadding(padding);
    Font font = Font.getDefault().derive(Font.BOLD, 9, Ui.UNITS_pt);
    titleField.setFont(font);
    bitmapField = new BitmapField(DesignSizes.newsIsLoading(),
            Field.FIELD_HCENTER);
    bitmapField.setPadding(padding);
    setBitmap(bean.getImgUrl());

    articleField = new RichTextField(parser.clean(bean.getNewsArticle()),
            RichTextField.USE_TEXT_WIDTH | RichTextField.TEXT_ALIGN_LEFT
                    | RichTextField.READONLY);
    // bitmap field for the add bitmap
    ad = new BitmapField(DesignSizes.adBanner(), Field.FIELD_TRAILING
            | Field.FIELD_HCENTER);
    // horizontal field manager to set the bitmapfield away from the
    // scrollable screen .. as its required to be only
    // on the bottom of the screen !

    admanager = new HorizontalFieldManager(
            VerticalFieldManager.NO_VERTICAL_SCROLL
                    | VerticalFieldManager.NO_VERTICAL_SCROLLBAR
                    | Field.FIELD_HALIGN_MASK);

    // the other stuff title bar + action bar + itemRow + button more
    otherStuff = new VerticalFieldManager(
            VerticalFieldManager.VERTICAL_SCROLL) {
        protected void sublayout(int maxWidth, int maxHeight) {
            // TODO Auto-generated method stub
            super.sublayout(maxWidth, maxHeight);
            setExtent(maxWidth, Display.getHeight() - ad.getHeight());
        }
    };
    admanager.add(ad);
    // font for the article
    Font artFont = Font.getDefault().derive(Font.PLAIN, 6, Ui.UNITS_pt);
    articleField.setPadding(padding);
    articleField.setFont(artFont);
    vvv.add(dateField);
    vvv.add(titleField);
    vvv.add(bitmapField);
    vvv.add(articleField);
    add(vvv);
    add(admanager);

    switch (Display.getWidth()) {
    case 320:
        getAd(adsBean[adCounter].getBlackberry320());
        break;
    case 360:
        getAd(adsBean[adCounter].getBlackberry360());
        break;
    case 480:
        getAd(adsBean[adCounter].getBlackberry480());
        break;
    case 640:
        getAd(adsBean[adCounter].getBlackberry640());
        break;
    }


}

private void setBitmap(final String url) {

    // TODO Auto-generated method stub\\

    UiApplication.getUiApplication().invokeLater(new Runnable() {

        public void run() {
            // TODO Auto-generated method stub
            final DownLoadImage dope = new DownLoadImage(url);
            bitmap = dope.getImage();
            Bitmap resized_bitmap = bitmap;
            Bitmap tempbitmap = new Bitmap(Display.getWidth() - 20,
                    (int) ((Display.getWidth() - 20) * 0.458));
            tempbitmap.createAlpha(Bitmap.TRUE_WHITE);
            resized_bitmap.scaleInto(tempbitmap, Bitmap.FILTER_LANCZOS);
            bitmap = tempbitmap;
            bitmapField.setBitmap(bitmap);

        }
    });
}

protected boolean keyDown(int keycode, int time) {
    int key = Keypad.key(keycode);
    if (key == Characters.ESCAPE) {
        try{
            this.time.cancel();
        }catch(Exception e){

        }
        UiApplication.getUiApplication().pushScreen(
                new NewsScreen_en(status, tour));

        return true;
    }
    return super.keyDown(keycode, time);
}

// =============================================================================================
    // for getting the ads ...
    // =============================================================================================
    private void loadAD(int timer) {
        System.out.println("Timer start! ");

            time = new Timer();
            task = new TimerTask() {

                public void run() {
                    time.cancel();
                    switch (Display.getWidth()) {
                    case 320:
                        getAd(adsBean[adCounter].getBlackberry320());
                        break;
                    case 360:
                        getAd(adsBean[adCounter].getBlackberry360());
                        break;
                    case 480:
                        getAd(adsBean[adCounter].getBlackberry480());
                        break;
                    case 640:
                        getAd(adsBean[adCounter].getBlackberry640());
                        break;
                    }
                    System.out.println("tik tik tik");
                }
            };
            time.schedule(task, timer * 1000);

    }

    private void getAd(final String url) {

        UiApplication.getUiApplication().invokeLater(new Runnable() {

            public void run() {
                // TODO Auto-generated method stub
                final DownLoadImage dope = new DownLoadImage(url);
                Bitmap bitmap = dope.getImage();
                ad.setBitmap(bitmap);
            }
        });


        //for saving more memo
        switch(Integer.parseInt(adsBean[adCounter].getAdDuration())){
        case 0:
            //
            break;
        default:
            System.out.println("loading ad! ");
            adCounter++ ;

            if(adCounter == adsBean.length || adCounter > adsBean.length){
            adCounter = 0;
            }
            loadAD(Integer.parseInt(adsBean[adCounter].getAdDuration()));
            break;
        }





    }
     }

Answer 1

要使屏幕可滚动，请为其添加可聚焦元素。如果屏幕或其区域没有可聚焦元素，则滚动此屏幕/区域时会遇到问题。

作为选项，在每个不可聚焦的字段后添加空的和可聚焦的分隔符字段。它不会影响应用程序的外观，但会有助于滚动。

黑莓屏幕不会一直向后滚动

1 个答案: