java - 从数组填充 GridView

Question

我有一组图像网址，我想使用 Picasso 下载图像并在 GridView 中显示它们。我当前的实现有效，但它将最后一个图像放入 GridView 中的每个 ImageView 中。

public class GridViewAdapter extends ArrayAdapter {

        Context context;

        public GridViewAdapter(Context context) {
            super(context, 0);
            this.context = context;
        }

        public int getCount() {
            return thumbnailURLS.size();
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            View row = convertView;

            if(row == null) {
                LayoutInflater inflater = ((Activity)context).getLayoutInflater();
                row = inflater.inflate(R.layout.grid_row, parent, false);

                ImageView gridImageView = (ImageView)row.findViewById(R.id.gridImageView);

                for(String s : thumbnailURLS) {
                    Picasso.with(context)
                            .load(s)
                            .placeholder(R.drawable.placeholder)
                            .error(R.drawable.placeholder)
                            .into(gridImageView);
                }
            }

            return row;
        }
    }

Answer 1

getView 对每个项目调用一次(即调用次数等于“getCount”)。最简单的方法是放弃 for 循环并使用位置参数查找缩略图 Url。

即

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View row = convertView;

        if(row == null) {
            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(R.layout.grid_row, parent, false);
        }

        ImageView gridImageView = (ImageView) row.findViewById(R.id.gridImageView);

        Picasso.with(context)
               .load(thumbnailURLs.get(position))
               .placeholder(R.drawable.placeholder)
               .error(R.drawable.placeholder)
               .into(gridImageView);

        return row;
    }