Question

1.i有一个网格视图，我必须从数据库获取图像路径，图像是可绘制的我的问题是，当我向下滚动网格视图图像变得不可见时，我有以下适配器什么帮助????

    import android.app.Activity;
    import android.graphics.drawable.Drawable;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseAdapter;
    import android.widget.ImageView;

    public class GridViewAdapter extends BaseAdapter {

    private Activity context;
    List<Fotota> list_popupBarBackGround;
    static final int ON_STICKER_LAYOUT=4;

    private static ViewHolder holder;
    private LayoutInflater l_Inflater;

    public GridViewAdapter(Activity context, List<Fotota> list_popupBarBackGround) {
    this.context = context;
    this.list_popupBarBackGround = list_popupBarBackGround;
    l_Inflater = LayoutInflater.from(context);
    }

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

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

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

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

    if (convertView == null) {

    holder = new ViewHolder();

    convertView = l_Inflater.inflate(R.layout.listview_griditem, null);
    holder = new ViewHolder();
    holder.imageView = (ImageView) convertView.findViewById(R.id.icon);


    convertView.setTag(holder);

   } else {

   holder = (ViewHolder) convertView.getTag();
   }              


 holder.imageView.setImageResource(context.getResources()
.getIdentifier(list_popupBarBackGround.get(position).getThumbnail(),     "drawable",context.getPackageName()));


   return convertView;
   }

   private static class ViewHolder {
   ImageView imageView;
   }

Answer 1

您需要返回getItem()中的位置。

同时在ViewHolder()方法中移除getView()的两个实例。只需宣布一次。

  @Override
   public Object getItem(int position) {
    return list_popupBarBackGround.get(position);
  }
  @Override
  public long getItemId(int position) {
      return position;  
  }

Answer 2

在适配器

中覆盖这两个方法

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

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

Answer 3

使用Recyclerview而不是Gridview。

recyclerView.setLayoutManager(new GridLayoutManager(this, numberOfColumns));

向下滚动时，网格视图项目变为不可见

3 个答案: