ListView - ImageLoader sposta Elenco/elementi su Scroll up

Question

Sto cercando una risposta mezza giornata, ma non riesco a trovare nulla anche se ho pensato che fosse un problema comune. Il mio problema: Ho un ListView che ha oggetti di dimensioni diverse (altezze). Ogni articolo contiene un ImageView. L'immagine di questo ImageView viene caricato in background da una classe ImageLoader:

imageLoader.DisplayImage(url, holder.image); 

Se ho scorrere verso il basso il ListView tutto funziona bene. le immagini vengono caricate e visualizzate (ovviamente nella parte inferiore dello schermo/elenco).

Ma se si scorre verso l'alto e l'immagine non è più memorizzata nella cache, quindi ImageLoader deve ricaricare l'immagine, i salti ListView/gli elementi vengono spostati. Penso che sia perché un nuovo View viene creato in cima alla lista, con un ImageView con altezza 0dp. Se l'immagine viene caricata e impostata su ImageView, l'altezza dello ImageView cambia automaticamente da 0 dpi alla dimensione dell'immagine. Ciò spingerebbe il ListView verso il basso, penso.

Ho provato a salvare l'altezza dello ImageViews se è stata impostata un'immagine e quindi impostare l'altezza dello ImageView che viene creato in cima all'altezza salvata. Ma senza successo ..

Non so se si può capire il mio problema: D lo spero :)

Grazie e buona giornata!

EDIT: Aggiunto ImageLoader Classe

public class ImageLoader { 

MemoryCache memoryCache=new MemoryCache(); 
FileCache fileCache; 
int size; 
Context context; 
private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>()); 
private HashMap<String, Integer> imagesSizes; 
ExecutorService executorService; 
Handler handler=new Handler();//handler to display images in UI thread 

public ImageLoader(Context context, int size){ 
    fileCache=new FileCache(context); 
    this.context = context; 
    executorService=Executors.newFixedThreadPool(5); 
    this.size = size; 
    imagesSizes = new HashMap<String, Integer>(); 
} 

final int stub_id=R.color.transparent; 
public void DisplayImage(String url, ImageView imageView) 
{ 
    imageViews.put(imageView, url); 
    Bitmap bitmap=memoryCache.get(url); 
    if(bitmap!=null){ 
     imageView.setImageBitmap(bitmap); 
     saveImageSize(imageView, url); 
    } 
    else 
    { 
     queuePhoto(url, imageView); 
     imageView.setImageResource(stub_id); 
     setImageSize(imageView, url); 
    } 
} 

public void DisplayImage(File file, ImageView imageView) 
{ 
    imageViews.put(imageView, file.getAbsolutePath()); 
    Bitmap bitmap=memoryCache.get(file.getAbsolutePath()); 
    if(bitmap!=null){ 
     imageView.setImageBitmap(bitmap); 
     saveImageSize(imageView, file.getAbsolutePath()); 
    } 
    else 
    { 
     queuePhoto(file, imageView); 
     imageView.setImageResource(stub_id); 
     setImageSize(imageView, file.getAbsolutePath()); 
    } 
} 

private void saveImageSize(ImageView imageView, String url){ 

    int height = imageView.getHeight(); 
    imagesSizes.put(url, height); 
    System.out.println("IMAGE SIZE: Save: " + url + " " + height); 
} 

private void setImageSize(ImageView imageView, String url){ 
    if(imageView != null && imagesSizes!=null && imagesSizes.containsKey(url)){ 
     imageView.getLayoutParams().height = imagesSizes.get(url); 
     imageView.requestLayout(); 
     System.out.println("IMAGE SIZE: Set: " + url + " " + imagesSizes.get(url)); 
    } 
} 


private void queuePhoto(String url, ImageView imageView) 
{ 
    PhotoToLoad p=new PhotoToLoad(url, imageView); 
    executorService.submit(new PhotosLoader(p)); 
} 

private void queuePhoto(File file, ImageView imageView) 
{ 
    PhotoToLoad p=new PhotoToLoad(file, imageView); 
    executorService.submit(new PhotosLoader(p)); 
} 

public Bitmap getImage(String url){ 
    return getBitmap(url); 
} 

private Bitmap getBitmap(String url) 
{ 
    File f=fileCache.getFile(url); 

    //from SD cache 
    Bitmap b = decodeFile(f); 
    if(b!=null) 
     return b; 

    //from web 
    try { 
     Bitmap bitmap=null; 
     URL imageUrl = new URL(url); 
     HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection(); 
     conn.setConnectTimeout(30000); 
     conn.setReadTimeout(30000); 
     conn.setInstanceFollowRedirects(true); 
     InputStream is=conn.getInputStream(); 
     OutputStream os = new FileOutputStream(f); 
     Utils.CopyStream(is, os); 
     os.close(); 
     conn.disconnect(); 
     bitmap = decodeFile(f); 
     return bitmap; 
    } catch (Throwable ex){ 
     ex.printStackTrace(); 
     if(ex instanceof OutOfMemoryError) 
      memoryCache.clear(); 
     return null; 
    } 
} 

//decodes image and scales it to reduce memory consumption 
private Bitmap decodeFile(File f){ 
    try { 
     //decode image size 
     BitmapFactory.Options o = new BitmapFactory.Options(); 
     o.inJustDecodeBounds = true; 
     FileInputStream stream1=new FileInputStream(f); 
     BitmapFactory.decodeStream(stream1,null,o); 
     stream1.close(); 

     //Find the correct scale value. It should be the power of 2. 
     final int REQUIRED_SIZE=size; 
     int width_tmp=o.outWidth, height_tmp=o.outHeight; 
     int scale=1; 
     while(true){ 
      if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE) 
       break; 
      width_tmp/=2; 
      height_tmp/=2; 
      scale*=2; 
     } 

     //decode with inSampleSize 
     BitmapFactory.Options o2 = new BitmapFactory.Options(); 
     o2.inSampleSize=scale; 
     FileInputStream stream2=new FileInputStream(f); 
     Bitmap bitmap=BitmapFactory.decodeStream(stream2, null, o2); 
     stream2.close(); 
     return bitmap; 
    } catch (FileNotFoundException e) { 
    } 
    catch (IOException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

//Task for the queue 
private class PhotoToLoad 
{ 
    public File file; 
    public String url; 
    public ImageView imageView; 
    public PhotoToLoad(String u, ImageView i){ 
     url=u; 
     imageView=i; 
     file = null; 
    } 

    public PhotoToLoad(File file, ImageView i){ 
     url=file.getAbsolutePath(); 
     imageView=i; 
     this.file = file; 
    } 
} 

class PhotosLoader implements Runnable { 
    PhotoToLoad photoToLoad; 
    PhotosLoader(PhotoToLoad photoToLoad){ 
     this.photoToLoad=photoToLoad; 
    } 

    @Override 
    public void run() { 
     try{ 
      if(imageViewReused(photoToLoad)) 
       return; 
      Bitmap bmp; 
      if(photoToLoad.file== null){ 
       bmp=getBitmap(photoToLoad.url); 
      } else { 
       bmp=decodeFile(photoToLoad.file); 
      } 
      memoryCache.put(photoToLoad.url, bmp); 
      if(imageViewReused(photoToLoad)) 
       return; 
      BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad); 
      handler.post(bd); 
     }catch(Throwable th){ 
      th.printStackTrace(); 
     } 
    } 
} 

boolean imageViewReused(PhotoToLoad photoToLoad){ 
    String tag=imageViews.get(photoToLoad.imageView); 
    if(tag==null || !tag.equals(photoToLoad.url)) 
     return true; 
    return false; 
} 

//Used to display bitmap in the UI thread 
class BitmapDisplayer implements Runnable 
{ 
    Bitmap bitmap; 
    PhotoToLoad photoToLoad; 
    public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;} 
    public void run() 
    { 
     if(imageViewReused(photoToLoad)) 
      return; 
     if(bitmap!=null) 
      photoToLoad.imageView.setImageBitmap(bitmap); 
     else 
      photoToLoad.imageView.setImageResource(stub_id); 
     if(photoToLoad.file== null){ 
      setImageSize(photoToLoad.imageView, photoToLoad.url); 
     } else { 
      setImageSize(photoToLoad.imageView, photoToLoad.file.getAbsolutePath()); 
     } 

    } 
} 



public void clearCache() { 
    memoryCache.clear(); 
    fileCache.clear(); 
} 

EDIT: Aggiunto Adapter:

public class LazyNewPostsAdapter extends BaseAdapter implements Constants{ 

private Activity activity; 
private ArrayList<Image> data; 
private static LayoutInflater inflater=null; 
private ImageLoader imageLoader; 
private AsyncHelper helper; 
public static final int VIEW_TYPE_LOADING = 0; 
public static final int VIEW_TYPE_ACTIVITY = 1; 

private int imgposition; 
Handler fmHandler = null; 

Handler handler = new Handler(){ 
    public void handleMessage(android.os.Message msg) { 
     switch(msg.what){ 
     case HANDLER_NEW_POST_VOTE_IMAGE: 
       int position = msg.arg1; 
      JSONObject json; 
      try { 
       json = new JSONObject((String) msg.obj); 

       int success = json.getInt("success"); 

       if(success == 1){ 

        int i_id = json.getInt("i_id"); 
        int votesUp = json.getInt("votes_up"); 
        int votesDown = json.getInt("votes_down"); 

        data.get(position).setVotesUp(votesUp); 
        data.get(position).setVotesDown(votesDown); 
        notifyDataSetChanged(); 
       } 

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

      break; 
     case HANDLER_USER_REPORTED_IMAGE: 
      JSONObject json2 = Utils.createJSON((String)msg.obj); 
      System.out.println("REPORT IMAGE " + json2); 
      if(json2 != null){ 
       try { 
        int success = json2.getInt("success"); 
        if(success==1){ 
         Toast.makeText(activity, "Image reported!", Toast.LENGTH_LONG).show(); 

        } 
       } catch (JSONException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } 
      } 
      break; 
     case HANDLER_IMAGE_SIZE_AVAILABLE: 
      String url = (String) msg.obj; 
      int height = msg.arg1; 
      int width = msg.arg2; 

      int imgPosition = findImageOfCertainURL(url); 
      System.out.println("GETVIEW HANDLER 1: IMAGE POSITION" + imgPosition); 

      if(imgPosition != -1){ 
       data.get(imgPosition).setHeight(height); 
       data.get(imgPosition).setWidth(width); 
      } 
      Message copyMsg = new Message(); 
      copyMsg.what = HANDLER_IMAGE_SIZE_AVAILABLE; 
      copyMsg.arg1 = height; 
      copyMsg.arg2 = width; 
      copyMsg.obj = url; 
      fmHandler.sendMessage(copyMsg); 
      notifyDataSetChanged(); 
      break; 
     } 
    }; 
}; 

private int findImageOfCertainURL(String url){ 
    for(int i = 0; i <data.size();i++){ 
     if((URL_FOLDER_IMAGES + data.get(i).getUrl()).equalsIgnoreCase(url)){ 
      return i; 
     } 
    } 
    return -1; 
} 

public LazyNewPostsAdapter(Activity a, ArrayList<Image> d, Handler fragmentHandler) { 

    activity = a; 

    data=d; 
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    helper = new AsyncHelper(activity, handler); 

    imageLoader=new ImageLoader(activity.getApplicationContext(), 600,handler) ; 
    fmHandler = fragmentHandler; 
} 

public void updateData(ArrayList<Image> d){ 
    data = d; 
    notifyDataSetChanged(); 
} 



public int getCount() { 
    return data.size()+1; 
} 

@Override 
public int getViewTypeCount() { 
    return 2; 
} 

@Override 
public int getItemViewType(int position) { 
    // TODO Auto-generated method stub 
    return (position >= data.size()) ? VIEW_TYPE_LOADING 
      : VIEW_TYPE_ACTIVITY; 
} 

@Override 
public boolean isEnabled(int position) { 
    return getItemViewType(position) == VIEW_TYPE_ACTIVITY; 
} 

public Object getItem(int position) { 
    return (getItemViewType(position) == VIEW_TYPE_ACTIVITY) ? data.get(position) : null; 
} 

public long getItemId(int position) { 
    return (getItemViewType(position) == VIEW_TYPE_ACTIVITY) ? position 
      : -1; 
} 

public View getFooterView(int position, View convertView, 
     ViewGroup parent) { 

     // the ListView has reached the last row 
     TextView tvLastRow = new TextView(activity); 
     if(AsyncHelper.isDownloadingImages){ 
      tvLastRow.setHint("Requesting new Images.."); 
     } else { 

      tvLastRow.setHint("Reached the last row."); 
     } 
     tvLastRow.setGravity(Gravity.CENTER); 
     return tvLastRow; 

} 

private OnClickListener myHotButtonClickListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     int position = (Integer) v.getTag(); 
     if(ActivityMain.user.isLoggedIn()){ 
      data.get(position).setThisUserVote(1); 
      helper.vote_image(position, data.get(position).getId(), HOT); 
     } else { 
      Toast.makeText(activity, "Login to vote" , Toast.LENGTH_SHORT).show(); 
     } 
    } 
}; 

private OnClickListener myColdButtonClickListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     int position = (Integer) v.getTag(); 
     if(ActivityMain.user.isLoggedIn()){ 
      data.get(position).setThisUserVote(2); 
      helper.vote_image(position, data.get(position).getId(), COLD); 
     }else { 
      Toast.makeText(activity, "Login to vote" , Toast.LENGTH_SHORT).show(); 
     } 
    } 
}; 

private OnClickListener myOptionsButtonClickListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     final int position = (Integer) v.getTag(); 
     Runnable optionsRunnable = new Runnable() { 

      @Override 
      public void run() { 


       openOptionsDialog(position); 

      } 
     }; 
     handler.postDelayed(optionsRunnable, 500); 


    } 
}; 
private void openOptionsDialog(final int imgposition){ 
    final CharSequence[] items = {"Share", "Save", "Report"}; 

    AlertDialog.Builder builder = new AlertDialog.Builder(activity); 
    builder.setTitle("Options"); 
    builder.setItems(items, new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int item) { 
      if(item==0){ 
       Utils.shareImage(activity, imageLoader.getImage(URL_FOLDER_IMAGES + data.get(imgposition).getUrl()) , data.get(imgposition).getTitle()); 
      } else if(item==1) { 
       Utils.saveImage(imageLoader.getImage(URL_FOLDER_IMAGES + data.get(imgposition).getUrl()),activity); 
      } else if(item==2) { 
       openReportDialog(imgposition); 
      } 
     } 
    }); 
    AlertDialog alert = builder.create(); 
    alert.show(); 
} 

private void openReportDialog(final int imgposition){ 

    AlertDialog.Builder builder = new AlertDialog.Builder(activity, R.style.AppCompatAlertDialogStyle); 
    builder.setTitle("Report This Image?"); 
    builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() { 

     @Override 
     public void onClick(DialogInterface dialog, int which) { 
      helper.reportImage(data.get(imgposition).getId()); 
     } 
    }); 
    builder.setNegativeButton("No", null); 

    AlertDialog alert = builder.create(); 
    alert.show(); 
} 

public View getView(final int position, View convertView, ViewGroup parent) { 
    if (getItemViewType(position) == VIEW_TYPE_LOADING) { 
     // display the last row 
     return getFooterView(position, convertView, parent); 
    } 
    View vi=convertView; 
    final ViewHolder holder; 
    final Image img = data.get(position); 
    boolean isViNull = false; 
    if(convertView==null){ 
    vi = inflater.inflate(R.layout.item_new_posts, null); 
     holder = new ViewHolder(); 
     isViNull = true; 
     holder.title=(BrushTextView)vi.findViewById(R.id.tv_newposts_title); 
     holder.image=(RatioImageView)vi.findViewById(R.id.iv_newposts_image); 
     holder.uploader = (BrushTextView) vi.findViewById(R.id.tv_newposts_uploader); 
     holder.upvotes = (BrushTextView) vi.findViewById(R.id.tv_newposts_upvotes); 
     holder.downvotes= (BrushTextView) vi.findViewById(R.id.tv_newposts_downvotes); 
     holder.options=(LinearLayout)vi.findViewById(R.id.ll_newposts_button_options); 

     holder.iv_hot=(ImageView)vi.findViewById(R.id.iv_newposts_button_upvote); 
     holder.iv_cold=(ImageView)vi.findViewById(R.id.iv_newposts_button_downvote); 
     holder.ll_hot=(LinearLayout)vi.findViewById(R.id.ll_newposts_button_upvote); 
     holder.ll_cold=(LinearLayout)vi.findViewById(R.id.ll_newposts_button_downvote); 

     vi.setTag(holder); 

    } else { 
     holder = (ViewHolder) vi.getTag(); 
    } 


    if(img.getHeight() != 0 && img.getWidth() != 0){ 

     holder.image.getLayoutParams().height = img.getHeight(); 
     holder.image.getLayoutParams().width = img.getWidth(); 
     holder.image.requestLayout(); 
    } 
    holder.ll_hot.setTag(position); 
    holder.ll_hot.setOnClickListener(myHotButtonClickListener); 
    holder.ll_cold.setTag(position); 
    holder.ll_cold.setOnClickListener(myColdButtonClickListener); 


    holder.options.setTag(position); 
    holder.options.setOnClickListener(myOptionsButtonClickListener); 


    changeVoteButtonImages(img, holder.iv_hot, holder.iv_cold); 
    if(img.getTitle()!=null){ 
     holder.title.setVisibility(View.VISIBLE); 
     holder.title.setText(img.getTitle()); 
    } else { 
     holder.title.setVisibility(View.GONE); 
    } 
    holder.uploader.setText(img.getUploader()); 
    holder.upvotes.setText(img.getVotesUp()+""); 
    holder.downvotes.setText(img.getVotesDown()+""); 
    String url = URL_FOLDER_IMAGES + img.getUrl(); 
    System.out.println("GETVIEW NEW POST ADAPTER: height = " + img.getHeight() + " width = " + img.getWidth()); 
    if(isViNull) 
    System.out.println("GETVIEW CONVERTVIEW: VI: " +vi.getHeight()); 
    imageLoader.DisplayImage(url, holder.image); 

    return vi; 
} 

private void changeVoteButtonImages(Image image, ImageView upvote,ImageView downvote){ 
    switch(image.getThisUserVote()){ 
    case 0: 
     upvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_hot_0)); 
     downvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_cold_0)); 
     break; 
    case 1: 
     downvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_cold_0)); 
     upvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_hot_1)); 
     break; 
    case 2: 
     upvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_hot_0)); 
     downvote.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_post_cold_1)); 
     break; 
    } 
} 

static class ViewHolder {    
    public BrushTextView title, uploader, upvotes, downvotes; 
    public ImageView iv_hot,iv_cold; 
    public LinearLayout options, ll_hot,ll_cold; 
    public RatioImageView image; 
} 

} 

Ed ecco il Fragment, che contiene il ListView

public class Fragment_New_Posts extends Fragment implements Constants, OnRefreshListener{ 

private static final String ARG_SECTION_NUMBER = "section_number"; 

private ListView list; 
private LazyNewPostsAdapter adapter; 
private Images images; 
private ArrayList<Image> imagesList; 
private SharedPreferences prefs; 
private Editor editor; 
private int visible_i_id; 
private SwipeRefreshLayout swipeLayout; 
private int option_image_filter; 
private AsyncHelper helper; 
private boolean onRefreshFired = false; 
private Parcelable state; 

public static Fragment_New_Posts newInstance(int sectionNumber) { 
    Fragment_New_Posts fragment = new Fragment_New_Posts(); 
    Bundle args = new Bundle(); 
    args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
    fragment.setArguments(args); 
    return fragment; 
} 

public static Fragment_New_Posts newInstance(int sectionNumber, Images imgs) { 
    Fragment_New_Posts fragment = new Fragment_New_Posts(imgs); 
    Bundle args = new Bundle(); 
    args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
    fragment.setArguments(args); 
    return fragment; 
} 

public void updateImages(Images images, boolean createNew, boolean loadOldImages){ 
    int i_id_position = 0; 
    this.images = images; 
    if(!images.hasErrorOccured){ 
     if(this.imagesList == null || createNew || onRefreshFired){ 
      this.imagesList = images.getListOfImages(); 
     } else { 
      this.imagesList.addAll(images.getListOfImages()); 
     } 
    } 

    if(loadOldImages){ 
     i_id_position = this.images.getIDPosition(visible_i_id); 
    } 
    if(onRefreshFired){ 
     swipeLayout.setRefreshing(false); 
     onRefreshFired = false; 
    } 
    synchronized (adapter) { 
     adapter.updateData(this.imagesList); 
     if(list!=null && createNew){ 
      if(loadOldImages){ 
       list.setSelection(i_id_position); 
      } else { 
       list.setSelection(0); 
      } 
     } 
    } 

} 

private Handler handler = new Handler(){ 
    public void handleMessage(android.os.Message msg) { 
     switch(msg.what){ 
     case HANDLER_MAIN_IMAGE_UPDATE: 
      String imagesString = (String) msg.obj; 
      Images imgs = new Images(imagesString); 
      updateImages(imgs, false, false); 
      if(imgs.hasErrorOccured){ 
       Toast.makeText(getActivity(), "Can\'t get new Images", Toast.LENGTH_SHORT).show(); 
      } 
      break; 
     case HANDLER_IMAGE_SIZE_AVAILABLE: 
      String url = (String) msg.obj; 
      int height = msg.arg1; 
      int width = msg.arg2; 

      int imgPosition = findImageOfCertainURL(url); 
      System.out.println("GETVIEW HANDLER 2: IMAGE POSITION" + imgPosition); 
      if(imgPosition != -1){ 
       imagesList.get(imgPosition).setHeight(height); 
       imagesList.get(imgPosition).setWidth(width); 
      } 

      break; 
     } 

    }; 
}; 

private int findImageOfCertainURL(String url){ 
    for(int i = 0; i <imagesList.size();i++){ 
     if((URL_FOLDER_IMAGES + imagesList.get(i).getUrl()).equalsIgnoreCase(url)){ 
      return i; 
     } 
    } 
    return -1; 
} 

public Fragment_New_Posts() { 
} 

public Fragment_New_Posts(Images imgs) { 
    this.images = imgs; 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 
    System.out.println("NEW POST FRAGMENT ONCREATE"); 
    View rootView = inflater.inflate(R.layout.fragment_new_posts, container, false); 
    prefs = getActivity().getSharedPreferences(PREF_WOODU, getActivity().MODE_PRIVATE); 
    editor = prefs.edit(); 
    if(prefs!=null){ 
     visible_i_id = prefs.getInt(PREF_NEW_POSTS_VISIBLE_I_ID, 0); 
     option_image_filter = prefs.getInt(PHP_TAG_IMAGE_FILTER, 0); 
    } 
    swipeLayout = (SwipeRefreshLayout) rootView.findViewById(R.id.swipe_container); 
    swipeLayout.setColorSchemeColors(R.color.red_hot); 
    swipeLayout.setOnRefreshListener(this); 
    helper = new AsyncHelper(getActivity(), handler); 
    imagesList = new ArrayList<Image>(); 
    if(images != null){ 
     imagesList = images.getListOfImages(); 
     System.out.println("SAVE IMAGES: load: imgsList " + imagesList); 

    } 
    list = (ListView) rootView.findViewById(R.id.lv_new_posts); 
    adapter = new LazyNewPostsAdapter(getActivity(), imagesList, handler); 
    list.setAdapter(adapter); 

    list.setOnScrollListener(new EndlessScrollListener() { 
     @Override 
     public void onLoadMore(int page, int totalItemsCount) { 
      if(imagesList!=null && imagesList.size()!=0){ 
       helper.getImageUpdate(imagesList.get(imagesList.size()-1).getId(), option_image_filter); 
      } 
     } 
    }); 

    if(images != null){ 
     updateImages(images, true, true); 
    } 

    return rootView; 
} 



@Override 
public void onPause() { 
    int lastVisposition = list.getLastVisiblePosition(); 
    if(lastVisposition>=0 && lastVisposition < this.imagesList.size()){ 
     visible_i_id = this.imagesList.get(list.getFirstVisiblePosition()).getId(); 
     editor.putInt(PREF_NEW_POSTS_VISIBLE_I_ID, visible_i_id); 
     editor.commit(); 
    } 

    super.onPause(); 
} 




@Override 
public void onResume() { 
    super.onResume(); 


} 

@Override 
public void onDestroy() { 
    if(images != null){ 
     editor.putString(PREF_NEW_POSTS_CURRENT_IMAGES, Utils.createJSONStringFromImageArrayList(imagesList, editor)); 
     editor.commit(); 
    } 
    super.onDestroy(); 
} 

@Override 
public void onRefresh() { 
    onRefreshFired = true; 
    if(prefs!=null){ 
     option_image_filter = prefs.getInt(PHP_TAG_IMAGE_FILTER, 0); 
    } 
    helper.getImageUpdate(0, option_image_filter); 
} 
} 

Ora qui ci sono molte molte informazioni e codice. Spero che non spaventi nessuno per aiutare: D

Grazie !!

Answer 1

probabilmente ho risolto il problema .. Finalmente .. La mia idea di impostare l'altezza del ImageView in GetView non era poi così male .. problema era:

mio ImageView è stato avvolto in un CardView in XML .. Quindi avevo bisogno di cambiare l'altezza del CardView invece del ImageView :)

Answer 2

WeakHashMap ... si utilizzano riferimenti deboli. Questo fa bene. Elimina oggetti se non più utilizzati. Quindi, basta cambiarlo in HashMap e si dovrebbe andare bene.

Answer 3

Please, Please, si prega di non "ri-inventare la ruota" e utilizzare qualsiasi lib là fuori per il caricamento delle immagini, la memorizzazione nella cache, ecc come Picasso, Affresco, planata ecc ....