AsyncTask doInBackground() 返回 null

Question

我正在尝试使用YouTube Data API。他们创建了一个 Java 客户端。 Here is the sample 我试图跟随它向他们的服务器发送请求。我不能拥有这个

// Call the API and print results.
SearchListResponse searchResponse = search.execute();
List<SearchResult> searchResultList = searchResponse.getItems();

在主线程中，因为 Android 不允许在主线程上联网。所以我尝试使用AsyncTask

public class youtubeSearchTask extends AsyncTask<YouTube.Search.List, Void, SearchListResponse> {

    @Override
    protected SearchListResponse doInBackground(YouTube.Search.List... params) {
        SearchListResponse a;
        try {
            a = params[0].execute();
        } catch (java.io.IOException ioe) {
            ioe.printStackTrace();
        }
        return a;
    }

    @Override
    protected void onPostExecute(SearchListResponse searchResponse) {
        List<SearchResult> searchResultList = searchResponse.getItems();
        List<String> videoIds = new ArrayList<String>();

        if (searchResultList != null) {

            // Merge video IDs
            for (SearchResult searchResult : searchResultList) {
                videoIds.add(searchResult.getId().getVideoId());
            }
            Joiner stringJoiner = Joiner.on(',');
            String videoId = stringJoiner.join(videoIds);

            // Call the YouTube Data API's youtube.videos.list method to
            // retrieve the resources that represent the specified videos.
            try {
                YouTube.Videos.List listVideosRequest = youtube.videos().list("snippet, statistics").setId(videoId);
                new videoSearchTask().execute(listVideosRequest);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

我试过了

return params[0].execute();

来自doInBackground 方法，但它让我考虑了可能的IOException。所以我更改了代码，现在它说的是variable 'a' might not have been initialized。我该怎么办？

Answer 1

也许如果你至少用一个 null 来初始化你的变量 a SearchListResponse a = null; 它将删除 a not initialized