Question

我正在为Blackberry设备构建一个应用程序，它将在主屏幕上显示一个自动收报机。我搜索了很多但找不到解决方案。

我已尝试在固定间隔后更新背景图像，但这会使手机变得非常慢。我不是主题开发人员，但尝试过它并再次失败。我想从我的应用程序中更新自动收报机的文本。

请帮助我，我真的被困在这里。提前致谢

Answer 1

StackOverflow中有类似的帖子希望能帮到你

Add A ticker to Blackberry Display

如果这不能解决您的问题，请回复

Answer 2

下面的代码可以让您更深入地了解Ticker 只需在下面的类中创建一个对象并传递所需的参数即可。这将使你的工作完成。我猜:)

import java.util.Timer;
import java.util.TimerTask;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Font;
import net.rim.device.api.ui.Graphics;

public class TickerField extends Field {
        String text;
        static final int screenWidth = Display.getWidth();
        int offset;
        private Timer timer = new Timer();
        final int delay = 30;
        private static int fontH = Font.getDefault().getHeight();
        private int w;
        private int h;
        private int bgColor = Color.WHITE;
        public TickerField(String text, int width, int height) {
                this.text = text;
                w = width;
                h = height;
                offset = w;
                final int textWidth = Font.getDefault().getAdvance(text);

                //schedule and start timertask 
                TimerTask timerTask = new TimerTask() {
                        public void run() {
                                offset--;
                                if (offset + textWidth == 0) {
                                        offset = screenWidth;
                                }
                                invalidate();
                        }
                };
                timer.scheduleAtFixedRate(timerTask, delay, delay);
        }
        public TickerField(String text) {
                this(text, screenWidth, fontH);
        }
        public TickerField(int width, int height) {
                this("", width, height);
        }
        public TickerField() {
                this("", screenWidth, fontH);
        }
        //set ticker text
        public void setText(String text) {
                this.text = text;
        }
        //get ticker text
        public String getText() {
                return text;
        }
        // implement layout to give specific arrangement to this field
        // Invoke Math.min() to return the smaller of the user specified w and h,
        // and the preferred width and height of the field.
        protected void layout(int width, int height) {
                width = Math.min(w, getPreferredWidth());
                height = Math.min(h, getPreferredHeight());
                setExtent(width, height);
        }
        // Implement the paint() to redraw the field with different
        // offset controlled by timer task.That will give the
        // ticker effect.
        protected void paint(Graphics graphics) {
                graphics.drawText(text, offset, 0);
        }

        public void setBgColor(int bgColor) {
                this.bgColor = bgColor;
        }
        //Implement the paintBackground() method to change the 
        //background color of the field.
        protected void paintBackground(Graphics g) {
                g.setBackgroundColor(bgColor);
                g.clear();
                super.paintBackground(g);
        }


        // Implement getPreferredWidth() and getPreferredHeight(), using the
        // screenWidth and font height to make sure that the ticker does not exceed
        // the dimensions of the
        // component.
        public int getPreferredWidth() {
                return screenWidth;
        }
        public int getPreferredHeight() {
                return fontH;
        }

}

快乐编码：）

黑莓主屏幕上的自动收报机

2 个答案: