从片段开始活动

Posted 2023-05-07

【中文标题】从片段开始活动

【英文标题】：Starting Activity From Fragment

【发布时间】：2016-03-31 11:18:47

【问题描述】：

我有两个 AsyncTask（FetchDataFromApi，FetchDataFromDb），它们都有一个“onPostExecute”方法的实现，每个都通过调用 passDataToDetailedActivity 方法来启动 DetailActivity。 每当我从 FetchFromApi onPostExecute 方法启动DetailedActivity 时，它都运行良好， 但整个问题是当我尝试从 FetchFromDb onPostExecute 方法启动DetailedActivity 时，因为DetailedActivity UI 的某些组件没有出现而其他组件出现。

请帮忙,,提前谢谢:)

public class MainFragment extends Fragment 

public final static String API_KEY = "b932ba435fc93a5944938fe9d44cd198";
public final String BASE_URL = "http://api.themoviedb.org/3/discover/movie?sort_by=&api_key=";


ArrayList<Movie> movies = new ArrayList<>();
movieAdapter adapter;
GridView gridview;
DbOpenHelper dbOpenHelper;
ArrayList<Movie> FavList = new ArrayList<>();


public MainFragment() 



public MainFragment(String SortBy) 
    if (SortBy == "fav") 
        new FetchDataFromDb().execute();
     else 
        new FetchDataFromApi(SortBy).execute();
    



@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
    View view = inflater.inflate(R.layout.fragment_main, container, false);
    gridview = (GridView) getActivity().findViewById(R.id.gridView);
    adapter = new movieAdapter(getActivity(), R.layout.movie_item, movies);
    return view;



class FetchDataFromApi extends AsyncTask<String, Void, Boolean> 
    String SORT_CATEGORY;

    FetchDataFromApi(String paramUrl) 
        SORT_CATEGORY = paramUrl;
    

    @Override
    protected Boolean doInBackground(String... params) 

        HttpURLConnection urlConnection = null;

        try 
            Uri uriBuilder = Uri.parse(BASE_URL).buildUpon()
                    .appendQueryParameter("sort_by", SORT_CATEGORY)
                    .appendQueryParameter("api_key", API_KEY)
                    .build();
            URL url = new URL(uriBuilder.toString());
            urlConnection = (HttpURLConnection) url.openConnection();

            InputStream in = urlConnection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in));
            StringBuilder sb = new StringBuilder();
            String line;

            while ((line = bufferedReader.readLine()) != null) 
                sb.append(line);
            

            String response = sb.toString();
            ParseJsonData(response);

         catch (MalformedURLException e) 
            e.printStackTrace();
         catch (IOException e) 
            e.printStackTrace();
         catch (JSONException e) 
            e.printStackTrace();
         finally 
            urlConnection.disconnect();
        

        return null;
    

    @Override
    protected void onPostExecute(Boolean result) 
        super.onPostExecute(result);
        gridview.setAdapter(adapter);
        gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) 
                PassDataToDetailedActivity(position);
            
        );
    


    private void ParseJsonData(String response) throws JSONException 
        String PosterBaseUrl = "http://image.tmdb.org/t/p/";
        String LargePoster = "w185";
        String SmallPoster = "";
        final String RESULTS = "results";
        final String ORIGINAL_TITLE = "original_title";
        final String OVERVIEW = "overview";
        final String RELEASE_DATE = "release_date";
        final String POSTER_PATH = "poster_path";
        final String VOTE_AVERAGE = "vote_average";
        final String POPULARITY = "popularity";
        final String ID = "id";



        JSONObject jsono = new JSONObject(response);
        Log.v("Json", response);
        JSONArray jarray = jsono.getJSONArray(RESULTS);

        for (int i = 0; i < jarray.length(); i++) 
            JSONObject object = jarray.getJSONObject(i);

            String id = object.getString(ID);
            String title = object.getString(ORIGINAL_TITLE);
            String releaseDate = object.getString(RELEASE_DATE);
            String overView = object.getString(OVERVIEW);
            String voteAverage = object.getString(VOTE_AVERAGE);
            String popularity = object.getString(POPULARITY);
            String posterPath = object.getString(POSTER_PATH);

            String BigPoster = PosterBaseUrl + LargePoster + posterPath;
            String MinPoster = PosterBaseUrl + SmallPoster + posterPath;

            Movie m = new Movie();
            m.setId(id);
            m.setTitle(title);
            m.setReleaseDate(releaseDate);
            m.setOverView(overView);
            m.setVoteAverage(voteAverage);
            m.setPopularity(popularity);
            m.setLargePoster(BigPoster);
            m.setMinPoster(MinPoster);

            movies.add(m);
        
    


private void PassDataToDetailedActivity(int position) 

    String id = movies.get(position).getId();
    String title = movies.get(position).getTitle();
    String releaseDate = movies.get(position).getReleaseDate();
    String overView = movies.get(position).getOverView();
    String voteAverage = movies.get(position).getVoteAverage();
    String popularity = movies.get(position).getPopularity();
    String BigPoster = movies.get(position).getLargePoster();
    String MinPoster = movies.get(position).getMinPoster();

    Intent intent = new Intent(MainActivity.context, DetailedActivity.class);
    intent.putExtra("id", id);
    intent.putExtra("title", title);
    intent.putExtra("releaseDate", releaseDate);
    intent.putExtra("overView", overView);
    intent.putExtra("voteAverage", voteAverage);
    intent.putExtra("popularity", popularity);
    intent.putExtra("MaxPoster", BigPoster);
    intent.putExtra("MinPoster", MinPoster);
    startActivity(intent);


public class FetchDataFromDb extends AsyncTask<String, Void, Boolean> 

    @Override
    protected Boolean doInBackground(String... params) 
        dbOpenHelper = new DbOpenHelper(MainActivity.context);
        movies.clear();
        movies = dbOpenHelper.getAllFavoritePosters();
        Log.v("database count", Integer.toString(FavList.size()));
        return null;
    

    @Override
    protected void onPostExecute(Boolean aBoolean) 
        super.onPostExecute(aBoolean);
        Log.v("database status", "Finished From Db");

        adapter.notifyDataSetChanged();
        gridview.setAdapter(adapter);
        gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) 
                PassDataToDetailedActivity(position);
            
        );
    

【问题讨论】：

您的意思是说您的详细活动正在打开，但该活动的某些 UI 没有显示。？

是的，但只有当我从 FetchDataFromDb 启动它时才会发生这种情况，从 FetchDataFromApi 启动 Activity 效果很好。

您是否检查过您传递的数据实际上是用于该活动的？

是的，伙计，我在手动编码时调试了它们，但它们也没有出现

你能展示你的xml布局代码吗？

【参考方案1】：

试试这个代码：

Intent in = new Intent(getActivity(), Opening_Activtiy_Name().class);
getActivity().startActivity(in);

注意：将您的 gridListener 带出该 post execute 方法

【讨论】：

它并没有真正帮助我怀疑这可能是因为片段附加的东西，但我调试并确保它不是问题。我真的被困在这个:(