2017-02-23 54 views
0

我創建了一個GridView,其中我加載數據。數據有一個圖像鏈接,我得到這個鏈接,並把它放在畢加索加載ImageView。 當我的GridView滾動結束時,我正在將更多數據加載到適配器。 如果適配器數據有更多的40個項目,神祕的滾動工作。 當我停留在適配器的中間位置並嘗試向上滾動時,適配器將我移動到第一個位置,並且所有圖像自動刷新。 任何人都可以幫助我嗎?GridView滾動神祕行爲後notifyDataSetChanged()

MyAdapter:

public class GridArrayAdapter extends BaseAdapter { 
private static final String URL_SITE = "some url"; 
private List<Movie> movies = new ArrayList<>(); 
private Context context; 


public GridArrayAdapter(Context context, List<Movie> model) { 
    super(); 
    this.movies = model; 
    this.context = context; 

} 

public void addMovies(List<Movie> newMovies){ 
    this.movies.addAll(newMovies); 
    notifyDataSetChanged(); 
} 

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

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

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

@Override 
public View getView(final int position, View convertView, final ViewGroup parent) { 
    Holder holder; 
    if(convertView == null) { 
     convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false); 
     holder = new Holder(); 
     holder.imageView = (ImageView) convertView.findViewById(R.id.thumbnail); 
     convertView.setTag(holder); 

    } else { 
     holder = (Holder) convertView.getTag(); 
     holder.imageView.setImageDrawable(null); 
    } 
    com.squareup.picasso.Picasso 
      .with(context) 
      .load(URL_SITE + movies.get(position).getPosterPath()) 
      .into(holder.imageView); 

    return convertView; 
} 
class Holder{ 
    ImageView imageView; 
}} 

滾動代碼:

 gridView.setOnScrollListener(new AbsListView.OnScrollListener() { 
     private boolean canScroll = false; 
     @Override 
     public void onScrollStateChanged(AbsListView view, int scrollState) { 
      if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) { 
       canScroll = false; 
      } else if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING || 
        scrollState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) { 
       canScroll = true; 
      } 
     } 

     @Override 
     public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { 
      if(firstVisibleItem + visibleItemCount == filmArray.size()&& canScroll) { 
       canScroll = false; 
       getPage(currentPage); 
      } 
     } 
    }); 

} 

獲取數據:

private void getPage(Integer page){ 
    Call<Result> callPage = service.getPopularPage(++page, MovieDBApi.API_KEY); 
    callPage.enqueue(new Callback<Result>() { 
     @Override 
     public void onResponse(Call<Result> call, retrofit2.Response<Result> response) { 
      currentPage = response.body().getPage(); 
      adapter.addMovies(response.body().getResults()); 
     } 

     @Override 
     public void onFailure(Call<Result> call, Throwable t) { 
      Log.d("onFailure", "Fail"); 
     } 
    }); 
} 
+1

刪除onScrollStateChanged()中的代碼。您不需要控制滾動狀態。你只需要識別列表的最後一個滾動並調用getPage()。 – nnn

回答

0

你的圖像刷新,因爲你沒有在你的畢加索加載圖像使用標籤。應該是:

com.squareup.picasso.Picasso 
      .with(context) 
      .load(URL_SITE + movies.get(position).getPosterPath()) 
      .tag(context) 
      .into(holder.imageView); 

你可以仔細閱讀本post

爲什麼你設置holder.imageView.setImageDrawable(null);標記。你可以刪除它並嘗試。但移動太快後圖像清爽非常簡單。