我試圖從API獲取一些數據返回null,但我總是在異步任務越來越空。這是我的AsyncTask:的AsyncTask與對象的ArrayList的結果在OnPostExecute
private class DownloadTask extends AsyncTask<Bundle, Void, List<Topic>> {
@Override
protected void onPreExecute() {
HomeActivity.mProgressBar.setVisibility(View.VISIBLE);
HomeActivity.mProgressBar.setIndeterminate(true);
}
@Override
protected List<Topic> doInBackground(Bundle... params) {
return downloadPhotos(params[0]);
}
@Override
protected void onPostExecute(List<Topic> topics) {
HomeActivity.mProgressBar.setVisibility(View.INVISIBLE);
HomeActivity.mProgressBar.setIndeterminate(false);
Log.d("List Size: ", ""+topics); // 0
adapter = new TopicListAdapter(activity, topics);
RecyclerView.LayoutManager manager = new MyCustomLayoutManager(activity);
recyclerView.setLayoutManager(manager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
}
}
用於檢索數據應該兩個數組合併成一個數組,因爲我是從兩個地方獲取數據的方法:
private List<Topic> downloadPhotos(Bundle params) {
String profileId = activity.getPreferencesManager().getProfileId();
List<Topic> topicsFromMe, topicsFromFriends;
topicsFromFriends = setValuesFromFriends(params);
topicsFromMe = setValuesFromMe(profileId, params);
topicsFromFriends.addAll(topicsFromMe);
sortTopics(topicsFromFriends);
int k = topicsFromFriends.size();
Log.d("List Size: ", "" + topicsFromFriends); // here also 0 for size
if (k > 10)
topicsFromFriends.subList(10, k).clear();
return topicsFromFriends;
}
這裏是一個方法,其中我設置值到數組列表。很奇怪,在這種情況下,RecyclerView是用這個數組填充的,但我沒有得到我想要的結果。例如,我應該對這個列表進行排序,並只顯示10條記錄。
private List<Topic> setValuesFromFriends(final Bundle params) {
final List<Topic> topics = new ArrayList<>();
activity.getSimpleFacebook().getFriends(new OnFriendsListener() {
@Override
public void onComplete(List<Profile> friends) {
for (final Profile profile : friends) {
activity.getSimpleFacebook().get(profile.getId(), "photos/uploaded", params,
new OnActionListener<List<Photo>>() {
@Override
public void onComplete(List<Photo> photos) {
for (final Photo photo : photos) {
// Initialize instance of Topic
final User user = photo.getFrom();
final Topic topic = new Topic();
topic.setCaption(photo.getName());
topic.setImageId(photo.getId());
topic.setCreatedTime(photo.getCreatedTime());
topic.setPostImage(photo.getSource());
topic.setUserId(user.getId());
topic.setName(user.getName());
final Bundle likeParams = new Bundle();
likeParams.putString("fields", "total_count");
likeParams.putString("limit", "100000");
activity.getSimpleFacebook().get(photo.getId(), "likes",
likeParams, new OnActionListener<List<Like>>() {
@Override
public void onComplete(List<Like> likes) {
topic.setNumOfLikes(likes.size());
topics.add(topic);
}
@Override
public void onThinking() {
super.onThinking();
}
});
}
}
});
}
}
});
return topics;
}