我正在尝试从网址页面解析XML
。为此,我使用了this IBM example中解释的SAX实现Adapter
以及我从this article获得的其他更改。我还尝试实现AsyncTask
进行解析并显示ProgressDialog
,但我认为这是我的应用程序开始崩溃的地方。
我真的不知道如何在我的代码中实现AsyncTask
,我相信我糟糕的实现会导致我的应用程序强行关闭。
MainActivity:
public class MainActivity extends Activity {
/** Called when the activity is first created. */
ListView lv1;
ProgressDialog ShowProgress;
public static ArrayList<MangaItem> MangaItemList = new ArrayList<MangaItem>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv1 = (ListView) findViewById(R.id.listView1);
ShowProgress = ProgressDialog.show(MainActivity.this, "",
"Loading. Please wait...", true);
//new loadingTask().execute("http://www.mangapanda.com/alphabetical");
new loadFeedTask().execute();
lv1.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Intent intent = new Intent(Intent.ACTION_VIEW).setData(Uri
.parse(MangaItemList.get(position).getMangaLink()));
startActivity(intent);
}
});
}
class loadFeedTask extends AsyncTask<String, Void, ArrayList<MangaItem>> {
private String feedUrl;
protected void onPostExecute(String s) {
lv1.setAdapter(new EfficientAdapter(MainActivity.this, MangaItemList));
//new MangaParserTask().execute();
ShowProgress.dismiss();
}
protected ArrayList<MangaItem> doInBackground(String... params) {
ArrayList<MangaItem> ParsedMangaItemList = new ArrayList<MangaItem>();
feedUrl = "http://www.mangapanda.com/alphabetical";
FeedParser parser = new SaxFeedParser(feedUrl);
ParsedMangaItemList = parser.parse();
for (MangaItem mitem : ParsedMangaItemList) {
MangaItemList.add(mitem);
}
return MangaItemList;
}
}
}
如何正确使用AsyncTask
,以便我的解析器返回ArrayList
,然后我可以将其放入ArrayAdapter
答案 0 :(得分:1)
使用此代码
try {
items = new ArrayList<String>();
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(true);
XmlPullParser xpp = factory.newPullParser();
xpp.setInput(new InputStreamReader(
getUrlData(" url")));
while (xpp.getEventType() != XmlPullParser.END_DOCUMENT) {
Log.i(TAG, "doc started");
if (xpp.getEventType() == XmlPullParser.START_TAG) {
if (xpp.getName().equals("entry")) {
items.add(xpp.getAttributeValue(0));
}
}
xpp.next();
}
} catch (Throwable t) {
Toast.makeText(this, "Request failed: " + t.toString(),
Toast.LENGTH_LONG).show();
}
获取网址数据方法
public InputStream getUrlData(String url) throws URISyntaxException,
ClientProtocolException, IOException {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet method = new HttpGet(new URI(url));
HttpResponse res = client.execute(method);
return res.getEntity().getContent();
}
答案 1 :(得分:1)
在子类(AsyncTask<Params, Progress, Result>
)中不正确地使用类型参数。重写AsyncTask
子类。
class loadFeedTask extends AsyncTask<String, Void, ArrayList<MangaItem>> {
protected void onPostExecute(ArrayList<MangaItem> list) {
lv1.setAdapter(new EfficientAdapter(MainActivity.this, list));
ShowProgress.dismiss();
}
protected ArrayList<MangaItem> doInBackground(String... params) {
ArrayList<MangaItem> list=null;
String feedUrl = "http://www.mangapanda.com/alphabetical";
FeedParser parser = new SaxFeedParser(feedUrl);
list = parser.parse();
MangaItemList=list;
return list;
}
}