CursorAdapter zeigt Bilder beim ersten Laden nicht an

Question

Ich bin dabei, eine App zu erstellen, wo ich einen Web - Server anrufe, die JSON - Daten herunterziehe, analysiere und in einer SQLite - Datenbank speichere und die Informationen der Benutzer.

Die erste Seite der App zeigt nur das Filmplakat, oder so soll es sein! Immer wenn die App neu installiert wird, wird das GridView nie aktualisiert, aber wenn es geschlossen und wieder geöffnet wird, werden die Filmplakate angezeigt, wie es sein sollte. Ich bin mir nicht sicher, was ich falsch mache, dass es nicht aktualisiert wird, wenn es frisch installiert ist.

Hier ist mein Code;

MainActivityFrament

public void update() { 
    Log.e(LOG_TAG, "In onUpdate"); 
    FetchMovieTask movieTask = new FetchMovieTask(getContext()); 
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity()); 
    String userChoice = sharedPreferences.getString(getString(R.string.pref_sort_key), getString(R.string.pref_sort_value_mostpop)); 
    movieTask.execute(userChoice); 
    progressBar.setVisibility(View.VISIBLE); 
} 

@Override 
public void onStart() { 
    super.onStart(); 
    Log.e(LOG_TAG, "In onStart"); 
    update(); 
} 

@Override 
public void onActivityCreated(Bundle savedInstanceState){ 
    Log.e(LOG_TAG, "In onActivityCreated"); 
    getLoaderManager().initLoader(MOVIE_LOADER, null, this); 
    super.onActivityCreated(savedInstanceState); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    Log.e(LOG_TAG, "In onCreateView"); 
    Cursor cursor = getActivity().getContentResolver().query(MovieContract.MovieEntry.CONTENT_URI, null, null, null, null); 

    customAdapter = new CustomAdapter(getActivity(), cursor, 0); 

    View rootView = inflater.inflate(R.layout.fragment_main, container, false); 

    progressBar = (ProgressBar) rootView.findViewById(R.id.progressBar); 
    gridView = (GridView) rootView.findViewById(R.id.gridView_movies); 
    gridView.setAdapter(customAdapter); 
    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      Cursor cursor = (Cursor) parent.getItemAtPosition(position); 

      Log.i(LOG_TAG, "set movie object values"); 
      int _id = cursor.getInt(cursor.getColumnIndex(MovieContract.MovieEntry._ID)); 
      if (cursor != null) { 
       Intent intent = new Intent(getActivity(), MovieDetailActivity.class); 
       intent.putExtra("movieId", _id); 
       Log.i(LOG_TAG, "About to start intent"); 
       startActivity(intent); 
      } 
     } 

    }); 

    return rootView; 
} 

@Override 
public Loader<Cursor> onCreateLoader(int id, Bundle args) { 
    Log.e(LOG_TAG, "In onCreateLoader"); 
    return new CursorLoader(
      getActivity(), 
      MovieContract.MovieEntry.CONTENT_URI, 
      MOVIE_COLUMNS, 
      null, 
      null, 
      null 
    ); 
} 


@Override 
public void onLoadFinished(Loader<Cursor> loader, Cursor data) { 
    Log.e(LOG_TAG, "In onLoadFinished"); 
    customAdapter.swapCursor(data); 
} 


@Override 
public void onLoaderReset(Loader<Cursor> loader) { 
    Log.e(LOG_TAG, "In onLoadReset"); 
    customAdapter.swapCursor(null); 
} 

Cursor

@Override 
public View newView(Context context, Cursor cursor, ViewGroup parent) { 
    Log.e(LOG_TAG, "In newView()"); 
    View view = LayoutInflater.from(context).inflate(R.layout.list_image_movie, parent, false); 

    return view; 
} 


@Override 
public void bindView(View view, Context context, Cursor cursor) { 

    Log.e(LOG_TAG, "in bindView()"); 
    String title =cursor.getString(cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_MOVIE_TITLE)); 
    Log.e(LOG_TAG, "Movie Title - " + title); 

    ImageView iv = (ImageView) view.findViewById(R.id.list_movie_pics_imageview); 

    int columIndex = cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_POSTER); 
    Bitmap image = Utility.getImage(cursor.getBlob(columIndex)); 

    iv.setImageBitmap(image); 
} 

AsyncTask

@Override 
protected Void doInBackground(String... params) { 
    Log.e(LOG_TAG, "In doInBackground"); 
    HttpURLConnection urlConnection = null; 
    BufferedReader reader = null; 

    String movieJsonStr = null; 

    try { 
     final String MOVIE_BASE_URL = "https://api.themoviedb.org/3/discover/movie?"; 
     final String SORT_PARAM = "sort_by"; 
     final String APIKEY_PARAM = "api_key"; 

     Uri builtUri = Uri.parse(MOVIE_BASE_URL).buildUpon() 
       .appendQueryParameter(SORT_PARAM, params[0]) 
       .appendQueryParameter(APIKEY_PARAM, BuildConfig.OPEN_MOVIE_MAP_API_KEY) 
       .build(); 

     URL url = new URL(builtUri.toString()); 

     Log.v(LOG_TAG, "Built URI :" + builtUri.toString()); 

     urlConnection = (HttpURLConnection) url.openConnection(); 
     urlConnection.setRequestMethod("GET"); 
     urlConnection.connect(); 

     InputStream inputStream = urlConnection.getInputStream(); 

     StringBuffer buffer = new StringBuffer(); 
     if (inputStream == null) { 
      return null; 
     } 

     reader = new BufferedReader(new InputStreamReader(inputStream)); 

     String line; 
     while ((line = reader.readLine()) != null) { 
      buffer.append(line + "\n"); 
     } 

     if (buffer.length() == 0) { 
      return null; 
     } 

     movieJsonStr = buffer.toString(); 
     parseMovieData(new JSONObject(movieJsonStr)); 
     checkDBValues(mContext); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } finally { 

     if (urlConnection != null) { 
      urlConnection.disconnect(); 
     } 

     if (reader != null) { 
      try { 
       reader.close(); 
      } catch (final IOException e) { 
       Log.e(LOG_TAG, "Error closing stream", e); 
      } 
     } 
    } 
    return null; 
} 

@Override 
protected void onPostExecute(Void aVoid) { 
    Log.e(LOG_TAG, "In onPostExecute"); 
    customAdapter.notifyDataSetChanged(); 
    MainActivityFragment.progressBar.setVisibility(View.GONE); 
} 

public void parseMovieData(JSONObject movieData) { 
    Log.e(LOG_TAG, "In parseMovieData"); 
    try { 
     JSONArray movieArray = movieData.getJSONArray("results"); 

     Time dayTime = new Time(); 
     dayTime.setToNow(); 
     int julianStartDay = Time.getJulianDay(System.currentTimeMillis(), dayTime.gmtoff); 

     if (movieArray != null) { 
      for (int i = 0; i < movieArray.length(); i++) { 
       JSONObject movies = movieArray.getJSONObject(i); 

       long dateTime = dayTime.setJulianDay(julianStartDay + i); 
       Bitmap moviePoster = Utility.getBitmapFromURL(CustomAdapter.IMAGE_BASE_URL + movies.getString(CustomAdapter.IMAGE_PATH)); 
       String moviePosterUrl = CustomAdapter.IMAGE_BASE_URL + movies.getString(CustomAdapter.IMAGE_PATH); 
       String movieTitle = movies.getString(CustomAdapter.MOVIE_TITLE); 
       String movieDescription = movies.getString(CustomAdapter.MOVIE_DESCRIPTION); 
       double movieRating = movies.getDouble(CustomAdapter.MOVIE_RATING); 
       String movieReleaseDate = movies.getString(CustomAdapter.MOVIE_RELEASE_DATE); 

       ContentValues movieValues = new ContentValues(); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_POSTER_URL, moviePosterUrl); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_POSTER, Utility.getBytes(moviePoster)); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_RELEASE_DATE, movieReleaseDate); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_DESCRIPTION, movieDescription); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_MOVIE_RATING, movieRating); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_MOVIE_TITLE, movieTitle); 
       movieValues.put(MovieContract.MovieEntry.COLUMN_DATE, dateTime); 

       if (MovieProvider.rowExists(movieTitle)) { 
        continue; 
       } 

       insertMoviesToDB(movieValues); 
      } 
     } 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } 
} 

public void insertMoviesToDB(ContentValues movieValues){ 
    Log.e(LOG_TAG, "In insertMoviesToDB"); 
    MovieProvider.mOpenHelper.getReadableDatabase().insert(MovieContract.MovieEntry.TABLE_NAME, null, movieValues); 
} 

public void checkDBValues(Context context) { 
    Log.e(LOG_TAG, "In checkDBValues"); 
    Cursor cursor = context.getContentResolver().query(
      MovieContract.MovieEntry.CONTENT_URI, 
      null, 
      null, 
      null, 
      null 
    ); 

    int count = 0; 
    while (cursor.moveToNext()) { 
     count++; 
    } 
    Log.i(LOG_TAG, "Got " + count + " values from the DB"); 
} 

MainLayout

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
     xmlns:tools="http://schemas.android.com/tools" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     tools:context=".MainActivityFragment"> 

<GridView 
     android:layout_width="fill_parent" 
     android:layout_height="match_parent" 
     android:verticalSpacing="0dp" 
     android:horizontalSpacing="0dp" 
     android:id="@+id/gridView_movies" 
     android:layout_gravity="center" 
     android:stretchMode="columnWidth" 
     android:numColumns="2"/> 

<ProgressBar 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/progressBar" 
    android:layout_gravity="center" 
    android:visibility="gone" /> 

Ich glaube, ich habe alle relevanten Informationen enthalten. Es werden keine Fehler erzeugt, daher werden keine relevanten Protokolle angezeigt. Wenn zusätzliche Informationen erforderlich sind, bitte fragen Sie und ich werde es zur Verfügung stellen.

Alle Informationen zu diesem Thema stark

noch gewürdigt werden würde

Answer 1

In OnPostExecute, notifyDatasetChanged wird nicht funktionieren, wie Daten in Cursor auf dem customAdapter der ist.

Sie müssen den neuen Cursor mit aktualisierten Informationen abrufen und dann den Änderungscursor aufrufen. Also, bevor der notifyDataSetChanged sollte es so etwas wie dieses

Cursor newCursor = getActivity().getContentResolver().query(MovieContract.MovieEntry.CONTENT_URI, null, null, null, null); 

customAdapter.changeCusrsor(newCursor); 

customAdapter.notifyDataSetChanged();