我正在尝试根据我在活动中收到的结果刷新Fragment的ListView的内容。
非常感谢任何帮助！
以下是代码：
MainActivity： 包com.example.deep.musico;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.net.ssl.HttpsURLConnection;
import kaaes.spotify.webapi.android.SpotifyApi;
import kaaes.spotify.webapi.android.SpotifyService;
import kaaes.spotify.webapi.android.models.Artist;
import kaaes.spotify.webapi.android.models.ArtistsPager;
import kaaes.spotify.webapi.android.models.Pager;
public class MainActivity extends ActionBarActivity {
Intent intent;
private static final String MAINFRAGMENT_TAG = "MFTAG";
private static final String LOGTAG = "MainActivity";
MainActivityFragment mainActivityFragment;
List<String> artistsName = new ArrayList<String>();
List<String> spotifyId = new ArrayList<String>();
List<String> artistImageURL = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// mainActivityFragment = new MainActivityFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.artists_detail_container, new MainActivityFragment(), MAINFRAGMENT_TAG).commit();
queryArtists(getIntent());
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
queryArtists(intent);
}
private void queryArtists(Intent intent){
this.intent = intent;
if(Intent.ACTION_SEARCH.equals(intent.getAction())) {
String queryString = intent.getStringExtra(SearchManager.QUERY).replace(" ", "+");
QueryArtistsFromSpotify queryArtistsFromSpotify = new QueryArtistsFromSpotify(this);
queryArtistsFromSpotify.execute(queryString);
Log.v(LOGTAG, "Getting fragment reference");
mainActivityFragment = (MainActivityFragment) getSupportFragmentManager().findFragmentByTag(MAINFRAGMENT_TAG);
if(mainActivityFragment == null) { Log.v(LOGTAG, "Fragment reference is null"); }
else {
Log.v(LOGTAG, "Fragment reference is NOT null");
// mainActivityFragment.artists = artistsName.toArray(new String[artistsName.size()]);
((ArrayAdapter<String>) mainActivityFragment.getListAdapter()).clear();
((ArrayAdapter<String>) mainActivityFragment.getListAdapter()).addAll(artistsName);
((ArrayAdapter<String>) mainActivityFragment.getListAdapter()).notifyDataSetChanged();
// mainActivityFragment.artistsAdapter.addAll(artistsName);
// mainActivityFragment.artistsAdapter.notifyDataSetChanged();
}
}
}
private class QueryArtistsFromSpotify extends AsyncTask<String, Void, ArtistsPager> {
Context context;
public QueryArtistsFromSpotify(Context context) {
this.context = context;
}
@Override
protected ArtistsPager doInBackground(String... params) {
SpotifyApi spotifyApi = new SpotifyApi();
SpotifyService spotifyService = spotifyApi.getService();
ArtistsPager artistsPager = spotifyService.searchArtists(params[0]);
return artistsPager;
}
@Override
protected void onPostExecute(ArtistsPager artistsPager) {
//super.onPostExecute(artistsPager);
List<Artist> artistsList = artistsPager.artists.items;
Iterator<Artist> iterator = artistsList.iterator();
while(iterator.hasNext()){
Artist artist = iterator.next();
artistsName.add(artist.id);
spotifyId.add(artist.id);
Log.v(LOGTAG, artist.id);
Log.v(LOGTAG, artist.name);
if(artist.images.size() == 0 ) {
artistImageURL.add("");
} else if(artist.images.size() > 0 ) {
artistImageURL.add(artist.images.get(artist.images.size() - 1).toString());
Log.v(LOGTAG, artist.images.get(artist.images.size() - 1).toString());
}
}
}
}
}
MainActivityFragment： 包com.example.deep.musico;
import android.app.Fragment;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* A placeholder fragment containing a simple view.
*/
public class MainActivityFragment extends ListFragment {
SearchView searchView;
ListView listView;
ArtistsAdapter artistsAdapter;
/* String[] items = new String[]{"Today - Sunny - 88/63", "Tomorrow - Foggy - 88/63",
"Wednesday - Cloudy - 88/63", "Thursday - Rainy - 88/63", "Friday - Sunny - 88/63"};*/
String[] artists = new String[]{};
public MainActivityFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
SearchManager searchManager = (SearchManager) getActivity().getSystemService(Context.SEARCH_SERVICE);
searchView = (SearchView) rootView.findViewById(R.id.artistsSearchView);
searchView.setSearchableInfo(searchManager.getSearchableInfo(getActivity().getComponentName()));
/*ArrayAdapter<String> artistsAdapter = new ArrayAdapter<String>(getActivity(),
R.layout.artists_view, R.id.artistNameTextView, items);*/
artistsAdapter = new ArtistsAdapter(getActivity(), R.layout.artists_view, R.id.artistNameTextView, new ArrayList<String>(Arrays.asList(artists)));
setListAdapter(artistsAdapter);
return rootView;
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
Intent intent = new Intent(getActivity(), SongsActivity.class);
startActivity(intent);
// super.onListItemClick(l, v, position, id);
}
class ArtistsAdapter extends ArrayAdapter<String> {
Context context;
public ArtistsAdapter(Context context, int resource, int textViewResource, ArrayList<String> items) {
super(context, resource, textViewResource, items);
this.context = context;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// return super.getView(position, convertView, parent);
// View view = LayoutInflater.from(context).inflate(R.layout.artists_view, parent, false);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(R.layout.artists_view, parent, false);
ImageView imageView = (ImageView) view.findViewById(R.id.artistsNameImageView);
TextView textView = (TextView) view.findViewById(R.id.artistNameTextView);
imageView.setImageResource(R.drawable.button_blank_blue_01);
if(artists.length > 0) {
textView.setText(artists[position]);
}
return view;
}
}
}
答案 0 :(得分：0)
是的，看看你的代码，当然，你片段中的数据是空的。为什么呢？
QueryArtistsFromSpotify queryArtistsFromSpotify = new QueryArtistsFromSpotify(this);
queryArtistsFromSpotify.execute(queryString);
- ＆GT;这两行将在UI线程上运行，这意味着它在另一个线程上运行。我们可以看到您在线程开始后立即更改数据 - ＆gt;结果是空数据。如果要显示在QueryArtistsFromSpotify中检索的数据，则必须在完成线程后显示！ - ＆GT;您必须通过onPostExecute通知。