我制作了一个适配器,以显示我们必须选择它们的许多城市。但是,当我向下滚动并再次返回时,所选项目将再次被取消选择。
我尝试将sethasStableIds设置为true,但这也不起作用
public class CitiesAdapter extends RecyclerView.Adapter<CitiesAdapter.ViewHolder> {
private static final String TAG = "CitiesViewAdapter";
private List<Cities> citiesModelList;
private Context mContext;
private OnClickListner mOnNoteListner;
public CitiesAdapter(List<Cities> citiesModelList, Context mContext , OnClickListner mOnNoteListner) {
this.citiesModelList = citiesModelList;
this.mContext = mContext;
this.mOnNoteListner = mOnNoteListner;
setHasStableIds(true);
}
@NonNull
@Override
public CitiesAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cities_listitems, viewGroup , false);
CitiesAdapter.ViewHolder holder = new CitiesAdapter.ViewHolder(view , mOnNoteListner , this);
return holder;
}
@Override
public void onBindViewHolder(@NonNull CitiesAdapter.ViewHolder viewHolder, int i) {
Log.d(TAG , "onBindViewHolder: called.");
Cities citiesmodels = citiesModelList.get(i);
viewHolder.tvCitiesName.setText(citiesmodels.getName());
}
@Override
public int getItemCount() {
return citiesModelList.size();
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public int getItemViewType(int position)
{
return position;
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
TextView tvCitiesName;
OnClickListner onClickListner;
private CitiesAdapter citiesAdapter;
public ViewHolder(@NonNull View itemView , OnClickListner onClickListner , CitiesAdapter citiesAdapter) {
super(itemView);
tvCitiesName = itemView.findViewById(R.id.tvCitiesName);
this.onClickListner = onClickListner;
itemView.setOnClickListener(this);
this.citiesAdapter = citiesAdapter;
}
@Override
public void onClick(View v) {
onClickListner.onItemClick(getAdapterPosition(),citiesAdapter.getItem(getAdapterPosition()));
}
}
public Cities getItem(int i){
return citiesModelList.get(i);
}
public interface OnClickListner{
void onItemClick(int position , Cities cities);
}
}
我在下面粘贴了我的适配器。任何帮助将不胜感激。谢谢[]
我制作了一个适配器,以显示我们必须选择它们的许多城市。但是,当我向下滚动并再次返回时,所选项目将再次被取消选择。我尝试设置sethasStableIds ...
在Cities
对象上,定义一个名为selected
的布尔属性,并使用一种方法来确定是否通过使用诸如boolean isSelected()
之类的吸气剂来选择它。然后,在适配器的onBindViewHolder
方法上添加以下内容:
发生这种情况是因为当我们滚动onBindViewHolder方法调用时。
请使用SparseBooleanArray
维护Android Recyclerview中Checkbox的状态。您可以点击此链接Using SparseBooleanArray to store Checkbox state in RecyclerView when scrolling