我正在使用theMovieDb.com API来获取数据。在启动应用程序时，它显示了流行电影的网格视图。在设置菜单中，它可以选择在更受欢迎和最高评级的基础上对网格视图进行排序。我正在使用共享首选项来存储用户首选项和关于首选项更改的侦听器。但无法对网格视图进行排序。
MainActivityFragment.java
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
GridView gridView = (GridView) rootView.findViewById(R.id.grid_view_movies);
final ImageAdapter mAdapter= new ImageAdapter(getActivity(),listMovie);
gridView.setAdapter(mAdapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
Movie movieSelected= listMovie.get(position);
String movieTitle=movieSelected.getTitle();
String movieThumbnail=movieSelected.getUrlThumbnail();
String movieReleaseDate=movieSelected.getReleaseDate();
String movieOverview=movieSelected.getOverview();
String movieRating = movieSelected.getRating();
Intent i = new Intent( getActivity() ,DetailsMovies.class);
i.putExtra(EXTRA_MESSAGE_1, movieThumbnail);
i.putExtra(EXTRA_MESSAGE_2, movieTitle);
i.putExtra(EXTRA_MESSAGE_3, movieReleaseDate);
i.putExtra(EXTRA_MESSAGE_4, movieRating);
i.putExtra(EXTRA_MESSAGE_5, movieOverview);
startActivity(i);
}
});
return rootView;
}
private void sendJsonRequest() {
//In the case of theMovieDB it is JSON Object Request
//Specify several argument in JSON Object Request
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET,
getRequestUrl(),
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
parseJsonResponse(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
requestQueue.add(request);
}
private void parseJsonResponse(JSONObject response) {
if (response == null || response.length() == 0) {
return;
}
long id = -1;
String title = Constants.NA;
String releaseDate = Constants.NA;
String synopsis = Constants.NA;
String urlThumbnail = Constants.NA;
String rating = Constants.NA;
try {
if (response.has(KEY_RESULTS)) {
JSONArray jsonArray = response.getJSONArray(KEY_RESULTS);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject currentMovies = jsonArray.getJSONObject(i);
//Get the id of the current movie
//If statement is used to check whether id is null or not.
if (currentMovies.has(KEY_ID) && !currentMovies.isNull(KEY_ID)) {
id = currentMovies.getLong(KEY_ID);
}
//Get the synopsis of the current movie
if (currentMovies.has(KEY_OVERVIEW) && !currentMovies.isNull(KEY_OVERVIEW)) {
synopsis = currentMovies.getString(KEY_OVERVIEW);
}
//Get the title of the current movie
if (currentMovies.has(KEY_TITLE) && !currentMovies.isNull(KEY_TITLE)) {
title = currentMovies.getString(KEY_TITLE);
}
//Get the urlThumbnail of the current movie
if (currentMovies.has(KEY_POSTER_PATH) && !currentMovies.isNull(KEY_POSTER_PATH)) {
urlThumbnail = currentMovies.getString(KEY_POSTER_PATH);
}
//Get the release date of the current movie
if (currentMovies.has(KEY_RELEASE_DATE) && !currentMovies.isNull(KEY_RELEASE_DATE)) {
releaseDate = currentMovies.getString(KEY_RELEASE_DATE);
}
//Get the rating of current movie
if (currentMovies.has(KEY_VOTE_AVERAGE) && !currentMovies.isNull(KEY_VOTE_AVERAGE)) {
rating = currentMovies.getString(KEY_VOTE_AVERAGE);
}
//Create movie object
movie=new Movie();
movie.setId(id);
movie.setTitle(title);
movie.setUrlThumbnail("http://image.tmdb.org/t/p/w185/" + urlThumbnail);
movie.setReleaseDate(releaseDate);
movie.setOverview(synopsis);
movie.setRating(rating);
//This decides when to add movies to the ArrayList
if (id != -1 && !title.equals(Constants.NA)) {
listMovie.add(movie);
}
}
}
} catch (JSONException e) {
Log.e("error", e.getMessage());
}
}
public String getRequestUrl() {
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(getActivity());
String order = pref.getString(getString(R.string.pref_order_key), getString(R.string.pref_popularity));
if(order.equals(getString(R.string.pref_rating)))
return URL + "vote_average" + UrlEndpoints.URL_PARAM + MyApplication.API_KEY;
else
return URL+ "popularity"+UrlEndpoints.URL_PARAM + MyApplication.API_KEY;
}
//Base Adapter which is used to put poster in grid view
public class ImageAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<Movie> movieItems;
public ImageAdapter(Context c, ArrayList<Movie> movieList) {
this.mContext = c;
this.movieItems = movieList;
}
public int getCount() {
return movieItems.size();
}
public Object getItem(int position) {
return movieItems.get(position);
}
public long getItemId(int position) {
return position;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null) {
inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
if (convertView == null) {
convertView = inflater.inflate(R.layout.grid_item_movies, null);
}
mNetworkImageView = (NetworkImageView) convertView.findViewById
(R.id.networkImageView);
//Getting movie data for the row
Movie m = movieItems.get(position);
//Thumbnail Image
//ImageLoader is used to load the images from json object retrieved.
imageLoader=VolleySingleton.getInstance().getImageLoader();
mNetworkImageView.setImageUrl(m.getUrlThumbnail(), imageLoader);
return convertView;
}
}
}
SettingsActivity.java
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Add 'general' preferences, defined in the XML file
// Added preferences from XML
addPreferencesFromResource(R.xml.pref_general);
// For all preferences, attach an OnPreferenceChangeListener so the UI summary can be
// updated when the preference changes.
// Added preferences
bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_order_key)));
}
/**
* Attaches a listener so the summary is always updated with the preference value.
* Also fires the listener once, to initialize the summary (so it shows up before the value
* is changed.)
*/
private void bindPreferenceSummaryToValue(Preference preference) {
// Set the listener to watch for value changes.
preference.setOnPreferenceChangeListener(this);
// Trigger the listener immediately with the preference's
// current value.
onPreferenceChange(preference,
PreferenceManager
.getDefaultSharedPreferences(preference.getContext())
.getString(preference.getKey(), ""));
}
@Override
public boolean onPreferenceChange(Preference preference, Object value) {
String stringValue = value.toString();
if (preference instanceof ListPreference) {
// For list preferences, look up the correct display value in
// the preference's 'entries' list (since they have separate labels/values).
ListPreference listPreference = (ListPreference) preference;
int prefIndex = listPreference.findIndexOfValue(stringValue);
if (prefIndex >= 0) {
preference.setSummary(listPreference.getEntries()[prefIndex]);
}
} else {
// For other preferences, set the summary to the value's simple string representation.
preference.setSummary(stringValue);
}
return true;
}