【发布时间】:2016-12-20 01:54:05
【问题描述】:
我正在创建一个可以抓取 YouTube 上播放列表列表的应用。它曾经是一个视频列表,但我已经更改了代码,现在它不允许我覆盖该方法。
我的理解是我应该用新的播放列表值而不是以前的视频来更改“扩展 AsyncTask”,但它仍然不起作用。
原来是这样的:
public abstract class GetPlaylistAsyncTask extends AsyncTask<String, Void, Pair<String, List<Video>>> {
现在是:
public abstract class GetPlaylistAsyncTask extends AsyncTask<String, Void, Pair<String, List<Playlist>>> {
这是错误所在:
mPlaylist = new Playlist(mPlaylistId);
initAdapter(mPlaylist);
new GetPlaylistAsyncTask(mYouTubeDataApi, mTitle, mSearchQuery) {
@Override
public void onPostExecute(Pair<String, List<Playlist>> result) {
handleGetPlaylistResult(mPlaylist, result);
}
}.execute(mPlaylist.playlistId, mPlaylist.getNextPageToken());
这是 AsyncTask:
public abstract class GetPlaylistAsyncTask extends AsyncTask<String, Void, Pair<String, List<Playlist>>> {
private static final String TAG = "GetPlaylistAsyncTask";
private static final Long YOUTUBE_PLAYLIST_MAX_RESULTS = 50L;
private static final String YOUTUBE_VIDEOS_PART = "snippet,contentDetails,statistics"; // video resource properties that the response will include.
private static final String YOUTUBE_VIDEOS_FIELDS = "items(id,snippet(title,description,thumbnails/high),contentDetails/duration,statistics)"; // selector specifying which fields to include in a partial response.
private YouTube mYouTubeDataApi;
private String mTitle;
private String mSearchQuery;
public GetPlaylistAsyncTask(YouTube api, String title, String searchQuery) {
mYouTubeDataApi = api;
mTitle = title;
mSearchQuery = searchQuery;
}
@Override
protected Pair<String, List<Playlist>> doInBackground(String... params) {
SearchListResponse searchResponse;
try {
YouTube.Search.List search = mYouTubeDataApi.search().list("id,snippet");
search.setKey(ApiKey.YOUTUBE_API_KEY);
search.setQ(mTitle + " " + mSearchQuery);
search.setType("video");
search.setFields("items(id/kind,id/videoId,snippet/title,snippet/thumbnails/default/url)");
search.setMaxResults(YOUTUBE_PLAYLIST_MAX_RESULTS);
searchResponse = search.execute();
} catch (IOException e) {
e.printStackTrace();
return null;
}
if (searchResponse == null) {
Log.e(TAG, "Failed to get playlist");
return null;
}
ArrayList videoIds = new ArrayList();
for (SearchResult item : searchResponse.getItems()) {
videoIds.add(item.getId().getVideoId());
}
VideoListResponse videoListResponse = null;
try {
videoListResponse = mYouTubeDataApi.videos()
.list(YOUTUBE_VIDEOS_PART)
.setFields(YOUTUBE_VIDEOS_FIELDS)
.setKey(ApiKey.YOUTUBE_API_KEY)
.setId(TextUtils.join(",", videoIds)).execute();
} catch (IOException e) {
e.printStackTrace();
}
return new Pair(searchResponse.getNextPageToken(), videoListResponse.getItems());
}
}
我不明白我的代码有什么问题,如果您能指出正确的方向,我将不胜感激。提前致谢!
【问题讨论】:
-
你得到什么错误?
-
方法不会覆盖其超类中的方法
-
将
public更改为protected