MainActvity güncellenmiyor

Question

AsyncTask arka plan iş parçacığı kullanarak MainActivity Fragmentinde film posterleri yükleyen bir MovieApp geliştiriyorum. Resimleri görüntülemek için gridview ve BaseAdapter kullanıyorum. Aşağıdaki kod.

MainActivityFragment.java:

package com.android.example.cinemaapp.app; 
import android.app.Fragment; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.net.Uri; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.GridView; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.Serializable; 
import java.net.HttpURLConnection; 
import java.net.URL; 
import java.util.HashMap; 


public class MainActivityFragment extends Fragment{ 

MoviePosterAdapter moviePosterAdapter; 
GridView posterGridView; 
public HashMap<String, JSONObject> movieMap; 

public MainActivityFragment() { 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setHasOptionsMenu(true); 
} 

@Override 
public void onStart(){ 
    super.onStart(); 
    updateMovies(); 
} 

@Override 
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
    inflater.inflate(R.menu.moviefragment, menu); 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    int id = item.getItemId(); 
    if (id == R.id.action_refresh) { 
     updateMovies(); 
    } 
    return super.onOptionsItemSelected(item); 
} 

public void updateMovies(){ 
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity()); 
    String sortBy = sharedPreferences.getString(getString(R.string.pref_sort_key), getString(R.string.pref_sort_popular)); 
    new FetchMoviePosterTask().execute(sortBy); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 

    View rootView = inflater.inflate(R.layout.fragment_main, container, false); 
    moviePosterAdapter = new MoviePosterAdapter(getActivity()); 
    posterGridView = (GridView) rootView.findViewById(R.id.gridview_movie); 
    posterGridView.setAdapter(moviePosterAdapter); 
    posterGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) { 
      // logic to start detail activity 
      startActivity(intent); 
     } 
    }); 
    return rootView; 
} 

public class FetchMoviePosterTask extends AsyncTask<String, String, Void> implements Serializable { 


    @Override 
    protected Void doInBackground(String... params) { 
     Log.v("FetchMoviePosterTask", "In background method"); 

     HttpURLConnection urlConnection = null; 
     BufferedReader reader = null; 

     String movieJsonStr; 

     try { 

      //logic to create uri builder 

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

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

      // Read the input stream into a String 
      InputStream inputStream = urlConnection.getInputStream(); 
      StringBuffer buffer = new StringBuffer(); 
      if (inputStream == null) { 
       // Nothing to do. 
       movieJsonStr = null; 
      } 
      reader = new BufferedReader(new InputStreamReader(inputStream)); 

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

      if (buffer.length() == 0) { 
       movieJsonStr = null; 
      } 
      movieJsonStr = buffer.toString(); 
      // Log.v("MainActivityFragment", "Movie json "+movieJsonStr); 

      try { 
       String[] posterPaths = getPosterPaths(movieJsonStr); 
       for(String path : posterPaths){ 
        publishProgress(path); 
       } 
      }catch(JSONException je){ 
       Log.e("MoviePosterPath","Error while parsing JSON"); 
      } 
     } catch (IOException e) { 
      Log.e("MoviePosterAdapter", "Error ", e); 
      movieJsonStr = null; 
     } finally { 
      if (urlConnection != null) { 
       urlConnection.disconnect(); 
      } 
      if (reader != null) { 
       try { 
        reader.close(); 
       } catch (final IOException e) { 
        Log.e("MoviePosterAdapter", "Error closing stream", e); 
       } 
      } 
     } 
     return null; 
    } 

    public String[] getPosterPaths(String movieJsonStr) throws JSONException{ 
     final String POSTER_PATH = //some value 
     final String POSTER_SIZE = //some value 
     JSONObject jsonObject = new JSONObject(movieJsonStr); 
     JSONArray results = jsonObject.getJSONArray("results"); 
     String[] posterStrs = new String[results.length()]; 
     movieMap = new HashMap<String, JSONObject>(); 

     for(int i =0; i < results.length(); i++){ 
      JSONObject movieObj = (JSONObject) results.get(i); 
      posterStrs[i] = POSTER_PATH + POSTER_SIZE + movieObj.getString("poster_path"); 
      movieMap.put(posterStrs[i], movieObj); 
     } 

     return posterStrs; 
    } 

    @Override 
    protected void onProgressUpdate(String... posterValues){ 
     Log.v("FetchMoviePosterTask", "In onProgress method"); 
     moviePosterAdapter.add(posterValues[0]); 
     super.onProgressUpdate(posterValues); 
    } 

    @Override 
    protected void onPostExecute(Void result) { 
     Log.v("FetchMoviePosterTask", "In onPostExecute method"); 
     moviePosterAdapter.notifyDataSetChanged(); 
     super.onPostExecute(result); 
    } 
} 
} 

MoviePosterAdapter.java:

package com.android.example.cinemaapp.app; 

import android.content.Context; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.ImageView; 

import com.squareup.picasso.Picasso; 

import java.util.ArrayList; 


public class MoviePosterAdapter extends BaseAdapter { 

ArrayList<String> movieArray = new ArrayList<String>(); 
private Context mContext; 

public MoviePosterAdapter(Context c) { 
    mContext = c; 
} 

void add(String path){ 
    movieArray.add(path); 
} 

void clear(){ 
    movieArray.clear(); 
} 

void remove(int index){ 
    movieArray.remove(index); 
} 

@Override 
public int getCount() { 
    return movieArray.size(); 
} 

@Override 
public Object getItem(int position) { 
    return movieArray.get(position); 
} 

@Override 
public long getItemId(int position) { 
    return 0; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    ImageView imageView; 
    if (convertView == null) { 
     // if it's not recycled, initialize some attributes 
     imageView = new ImageView(mContext); 

     imageView.setScaleType(ImageView.ScaleType.FIT_XY); 

    } else { 
     imageView = (ImageView) convertView; 
    } 

    Picasso.with(mContext).load(movieArray.get(position)).into(imageView); 
    return imageView; 
} 
} 

Sorun: Uygulama ilk başlatıldığında, UI imageviews doldurulur almıyor. Ben 'Yenile' düğmesini tıkladığınızda LogCat ben kontrol doBackground(), onProgressUpdate() ve onPostExecute().

içinden akıyor görebiliyordu veya i başka bir etkinlik ya da uygulamaya giderseniz ve mükemmel iyi çalışıyor (onResume()) Movie uygulaması UI geri dönün. Görüntüler görüntülenir.

Şimdiden çok teşekkürler!

Answer 1

'dan onCreateView'a updateMovies();'u değiştirmelisiniz. Gabe Sechan'ın dediği gibi, yaşam döngüsü hakkında yanılıyorsunuz. Fragment yaşam döngüsü hakkında biraz araştırma yapmaya çalışın.

Answer 2

Sadece yöntem updateMovies(); posterGridView = (GridView) rootView.findViewById'den (R.id.gridview_movie) sonra onCreateView() 'dan;

call from start();