java - 如何使用共享首选项在回收器 View 中保存复选框选择？

Question

我在Recycler View中使用了checkBox，当选择checkBox时，ArrayList favorite会根据位置填充ArrayList list_items中的新项目，当单击 Collection 夹按钮时，Recycler View会填充ArrayList favorite，但复选框的选择消失，当选择onBackPressed时，Recycler View会显示填充ArrayList list_items，而没有选择checkBoxes，我尝试共享首选项来解决此问题，并且如果我关闭应用程序但没有成功，也会保留checkBoxes选择

    class RecyclerView_dAdapter extends RecyclerView.Adapter {

private List<List_Item> list_items;
private ArrayList favorite = new ArrayList();
private List<List_Item> favorite_itemes = new ArrayList<>();
private Context context;

RecyclerView_dAdapter(List<List_Item> list_Item, Context context) {
list_items = list_Item;
this.context = context;
}

@Override
public RecyclerView_dAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_item, parent, false);
return new ViewHolder(v);
}

@Override
public void onBindViewHolder(final RecyclerView_dAdapter.ViewHolder holder, final int position) {
final List_Item current = list_items.get(position);
final String name = current.getName();
holder.TextName.setText(name);

 holder.TextName.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(context, Show_Team_Activity.class);
        intent.putExtra("Team_num", name);
        context.startActivity(intent);
    }
});
holder.favorite_checkBox.setChecked(favorite_itemes.contains(current)); 
holder.setItemClickListener(new ItemClickListener() {
    @Override
    public void onItemClick(View v, int pos) {
        CheckBox chk = (CheckBox) v;
        if (chk.isChecked()) {
           favorite_itemes.add(list_items.get(pos));
            chk.setChecked(true);
        } else if (!chk.isChecked()) {               
            favorite_itemes.remove(list_items.get(pos));
            chk.setChecked(false);
        }
    }
});

}
ArrayList favorite_array(){
for (int i = 0; i < favorite_itemes.size(); i++){
    favorite.add(favorite_itemes.get(i));
}return favorite;
}

@Override
public int getItemCount() {
return list_items.size();
}

class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {      
private TextView TextName;
private CheckBox favorite_checkBox;
ItemClickListener itemClickListener;
ViewHolder(View view) {
    super(view);
    TextName = (TextView) view.findViewById(R.id.textView_rowitem);
    favorite_checkBox = (CheckBox) view.findViewById(R.id.favorite_checkBox);
   favorite_checkBox.setOnClickListener(this);
}
public void setItemClickListener(ItemClickListener ic) {
    this.itemClickListener = ic;
}

@Override
public void onClick(View v) {
    this.itemClickListener.onItemClick(v, getLayoutPosition());
}
}
 }

Answer 1

使用以下步骤: 1. 将您的favourite_items转换为JSONArray并将其转换为字符串

将字符串存储在 SharedPreferences 中

在创建时检索共享首选项，将其转换回 JSON 数组，然后转换为 ArrayList

遍历ArrayList中是否包含当前复选框，将其标记为选中。

看看这个 https://stackoverflow.com/a/10238647/2555419