我已经开发了一个Android RSS reader。我已经创建了一个选项卡布局，并为每种类型的新闻（比如标题、国家、国际等）创建了每个选项卡。
然后我在 tablayout 的第一页的自定义列表视图中列出了 RSS 标题及其图像。
见下图。
现在，当用户单击新闻标题时，会打开另一个带有新闻描述的活动（页面）。
我的问题是当用户单击选项卡并加载时，如果互联网连接不可用，我想显示一个带有两个按钮的对话框Retry& Exit。
当用户单击Retry活动时应重新加载。但在我的代码中，它仅重新加载当前活动并仅显示该活动而不是包含选项卡布局的主要活动。
下面是我的代码。
public class International extends Activity {
static final String URL = "http://www.abcd.com/en/taxonomy/term/3/0/feed";
static final String KEY_HEAD = "item";
static final String KEY_DATE = "pubDate";
ListView list;
InternationalAdapter adapter;
public static String[] Title;
public static String[] Description;
public static String[] image;
public static String[] Date;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.headlines);
Bundle mybundle = new Bundle();
mybundle.putString("number", "0");
new DoInBackground().execute();
}
public void do_update()
{
internationalparser.parse();//this is the function to parse RSS feeds
}
public void populate_listview()
{
ArrayList<HashMap<String, String>> newsList = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML from URL
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_HEAD);
// looping through all song nodes <song>
NodeList itemLst = doc.getElementsByTagName("item");
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
//map.put(KEY_DATE, parser.getValue(e, KEY_DATE));
newsList.add(map);
}
list=(ListView)findViewById(R.id.list);
// Getting adapter by passing xml data ArrayList
adapter=new InternationalAdapter(this, newsList);
list.setAdapter(adapter);
// Click event for single list row
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Intent myintent = new Intent("com.abcd.rssreaderinternationalpodcast.PODCAST");
Bundle mybundle = new Bundle();
mybundle.putInt("number", position);
myintent.putExtras(mybundle);
startActivity(myintent);
}
});
}
private class DoInBackground extends AsyncTask<Void, Void, Void>
implements DialogInterface.OnCancelListener
{
private ProgressDialog dialog;
private Intent intent;
private Intent intent2;
public void onPreExecute()
{
dialog = ProgressDialog.show(International.this, "", "Loading", true);
}
protected Void doInBackground(Void... unused)
{
do_update();
return null;
}
public void retry()
{
internationalparser.parse();
}
protected void onPostExecute(Void unused)
{
if(International.Title!=null)
{
dialog.dismiss();
populate_listview();
}
if(International.Title==null)
{
dialog.dismiss();
AlertDialog.Builder alertbox = new AlertDialog.Builder(International.this);
alertbox.setMessage("Error in connection!");
alertbox.setPositiveButton("Retry", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
retry(); //here i want to reload activity
}
});
alertbox.setNegativeButton("Exit", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
finish();
}
});
alertbox.show();
}
}
public void onCancel(DialogInterface dialog)
{
cancel(true);
dialog.dismiss();
}
}
}
谢谢。