如何用 ArrayList 替换 String[]？

Question

I'm trying to populate my gridview with images using picasso. I'm using jsoup to collect the image links and placing them into a ArrayList. I have something wrong with my ImageAdapter cause none of my images load when I start the app. My log shows the links being collected so that works. Any help will be appreciated. I'm posting the entire code for the Activity.

   public class MainActivity extends Activity
  {GridView grid;
String url="http://dstreet.site/";
String link,title,src;
ArrayList list= new ArrayList();



   @Override
   protected void onCreate(Bundle savedInstanceState)
   {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    Scrapper();
    grid = (GridView)findViewById(R.id.grid);
    grid.setAdapter(new ImageAdapter(this, list));


    }


public class ImageAdapter extends BaseAdapter {


    ArrayList list;
    private LayoutInflater inflater;

    Context c;
     int mCount;

    ImageAdapter(Context context, ArrayList list) {
        inflater = LayoutInflater.from(context);
        c = context;

        mCount = list.size();
        this.list=list;

    }

    @Override
    public int getCount() {
        return mCount;
    }

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

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

    @Override
    public View getView(int position, View 
    convertView, ViewGroup parent) {
        final ViewHolder holder;
        View view = convertView;
        if (view == null) {
            view = inflater.inflate(R.layout.img, parent, 
       false);
            holder = new ViewHolder();
            assert view != null;

            holder.imageView = (ImageView) 
      view.findViewById(R.id.image);


            view.setTag(holder);
        } else {
            holder = (ViewHolder) view.getTag();
        }

        Picasso.get()
            .load(list.get(position))
            .placeholder(R.drawable.ic_launcher)
            .error(R.drawable.ic_launcher)
            .fit()
            .into(holder.imageView, new Callback() {

                @Override
                public void onError(Exception p1)

    {holder.imageView.setVisibility(View.INVISIBLE);
                    // TODO: Implement this method
                }


                @Override
                public void onSuccess() {

   holder.imageView.setVisibility(View.VISIBLE);
                    }


            });

        return view;
    }
}

static class ViewHolder {
    ImageView imageView;

}
public void Scrapper()
{
    Content content= new Content();
    content.execute();
}

public class Content extends 
   AsyncTask<Void,Void,Void>
{

    @Override
    protected Void doInBackground(Void[] p1)
    {
        // TODO: Implement this method

        try
        {
            Document doc = Jsoup.connect(url).get();
            // Identify Table Class "worldpopulation"
            for (Element table : 
     doc.select("div[class=poster]")) {

                Elements imgSrc = 
   table.select("img[src]");
                // Get only src from img src
                src = imgSrc.attr("src");
                list.add(src);
            }







            Log.d("image links",list.toString());
        }
        catch (IOException e)
        {e.printStackTrace();


        }
        return null;


    }

}}

Answer 1

如果要将 String[] 替换为 ArrayList，则需要使用 ArrayList.get(position) 而不是 IMAGE_URLS [position]。

Answer 2

It looks like you're not iterating over the elements after you queried the table for images:

for (Element table : doc.select("div[class=poster]")) {

    Elements imgSrc = table.select("img[src]");
    src = imgSrc.attr("src");
    list.add(src);

}

Something like this should do it:

doc.select("div[class=poster]")               // get list of div
   .stream()                                  // for each div
   .map(table -> table.select("img[src]"))    // find all images
   .flatmap(Elements::stream)                 // collapse images into 1 list
   .map(imgSrc -> imgSrc.attr("src"))         // for each image
   .forEach(list::add);                       // add to Collection