为加载Gridview创建自定义类

public class GridViewAdapter extends BaseAdapter {
    private Context mContext;
    private List<String> mData;

    public GridViewAdapter(Context context, List<String> data) {
        mContext = context;
        mData = data;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.grid_item_layout, parent, false);
            holder = new ViewHolder();
            holder.textView = convertView.findViewById(R.id.text_view);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        String dataItem = mData.get(position);
        holder.textView.setText(dataItem);

        return convertView;
    }

    private static class ViewHolder {
        TextView textView;
    }
}

GridView gridView = findViewById(R.id.grid_view);
List<String> data = new ArrayList<>();
// 添加数据项到data中
GridViewAdapter adapter = new GridViewAdapter(this, data);
gridView.setAdapter(adapter);