我为黑莓（java）开发了一个 Rss 应用程序，并成功显示了来自 Rss 文件的标题（需要在线播放的广播频道列表）。我已经开发了播放这些广播频道列表的代码，但我的要求是播放第一个频道（第一个列表）当我的列表最初（频道列表）显示时，任何人都可以帮助我在哪里编写我的逻辑（默认播放第一个频道）以在我的频道立即显示后执行？
这是我的 Rss 代码：
public class RssScreen extends MainScreen implements ListFieldCallback,FieldChangeListener {
Connection _connectionthread;
private static ListField _list;
String image;
String title;
private static Vector listElements = new Vector();
private static Vector listImage = new Vector();
public long mycolor ;
VerticalFieldManager mainManager;
VerticalFieldManager subManager;
int selectedList;
Radio radio;
public RssScreen(){
final Bitmap backgroundBitmap = Bitmap.getBitmapResource("blackbackground.png");
mainManager = new VerticalFieldManager(Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR )
{
public void paint(Graphics graphics)
{
graphics.drawBitmap(0, 0, Display.getWidth(),Display.getHeight(),backgroundBitmap, 0, 0);
super.paint(graphics);
}
};
subManager = new VerticalFieldManager(Manager.VERTICAL_SCROLL | Manager.VERTICAL_SCROLLBAR )
{
protected void sublayout( int maxWidth, int maxHeight )
{
int displayWidth = Display.getWidth();
int displayHeight = Display.getHeight();
super.sublayout( displayWidth, displayHeight);
setExtent( displayWidth, displayHeight);
}
};
add(mainManager);
_list = new ListField()
{
protected boolean navigationClick(int status, int time)
{
return true;
}
public void paint(Graphics graphics)
{
graphics.setColor((int) mycolor);
super.paint(graphics);
}
};
mycolor = 0x00FFFFFF;
_list.invalidate();
_list.setEmptyString("* Feeds Not Available *", DrawStyle.HCENTER);
_list.setRowHeight(50);
_list.setCallback(this);
mainManager.add(subManager);
listElements.removeAllElements();
_connectionthread = new Connection();
_connectionthread.start();
}
private class Connection extends Thread
{
public Connection()
{
super();
}
public void run() {
Document doc;
StreamConnection conn = null;
InputStream is = null;
try {
conn = (StreamConnection) Connector.open("http://toucheradio.com/toneradio/android/toriLite/toriplaylist.xml"+";deviceside=true");
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
docBuilderFactory.setIgnoringElementContentWhitespace(true);
docBuilderFactory.setCoalescing(true);
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
docBuilder.isValidating();
is = conn.openInputStream();
doc = docBuilder.parse(is);
doc.getDocumentElement().normalize();
NodeList listImg = doc.getElementsByTagName("title");
for (int i = 0; i < listImg.getLength(); i++) {
Node textNode = listImg.item(i).getFirstChild();
listElements.addElement(textNode.getNodeValue());
image=textNode.getNodeValue();
}
NodeList list = doc.getElementsByTagName("image");
for (int a = 0; a < list.getLength(); a++) {
Node textNode1 = list.item(a).getFirstChild();
listImage.addElement(textNode1.getNodeValue());
}
}
catch (Exception e) {
System.out.println(e.toString());
} finally {
if (is != null) {
try { is.close();
} catch (IOException ignored) {}
} if (conn != null) {
try { conn.close(); }
catch (IOException ignored) {}
} } UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
_list.setSize(listElements.size());
subManager.add(_list);
invalidate();
}
});
}
}
public void drawListRow(ListField list, Graphics g, int index, int y, int w)
{
String title=(String)listElements.elementAt(index);
String image=(String)listImage.elementAt(index);
// Bitmap image1= getBitmapFromUrl(image);
System.out.println("Title"+title);
System.out.println("Image"+image);
int yPos = 0+y;
g.drawLine(0, yPos, w, yPos);
g.drawText(title, 0, y, 0, w);
// g.drawBitmap(0,y,image1.getWidth(),image1.getHeight(),image1,0,0);
}
public Object get(ListField list, int index)
{
return listElements.elementAt(index);
}
public int indexOfList(ListField list, String prefix, int string)
{
return listElements.indexOf(prefix, string);
}
public int getPreferredWidth(ListField list)
{
return Display.getWidth();
}
public void insert(String toInsert, int index) {
listElements.addElement(toInsert);
}
public void fieldChanged(Field field, int context) {
}
}