在 RecyclerView 中获取微调器选择的项目

Question

我在 RecyclerView 中添加了 Spinner ，当我试图获取旋转器选择的项目数据时，它获得 another/wrong 位置数据，有人建议我获得正确的选择项目位置来自 Spinner onItemSelected

这是我的代码

@Override
public void onBindViewHolder(final QuestionHolder holder, final int position) {
        if (position % 2 == 1)
            holder.itemView.setBackgroundColor(Color.parseColor("#F8F8F8"));
        adapter = new ArrayAdapter<Option>(binding.getRoot().getContext(),
                        R.layout.item_spinner, questionList.get(position).getOptions());
        adapter.setDropDownViewResource(R.layout.item_spinner);
        binding.optionSpinner.setAdapter(adapter);

        binding.serialNo.setText((position + 1) + ".");
        binding.setQuestion(questionList.get(position));
        binding.executePendingBindings();
        binding.optionSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(holder.itemView.getContext(), position+" : "+binding.optionSpinner.getSelectedItem().toString(), Toast.LENGTH_SHORT).show();
                spinnerData.setSelectedData(position, binding.optionSpinner.getSelectedItem().toString());
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

    }

Answer 1

我想你必须试试这个

  showSpinnerList.setOnItemSelectedListener(new 
         AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int 
               position, long id) {
                // On selecting a spinner item

                String item = parent.getItemAtPosition(position).toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // todo for nothing selected
            }
        });

Answer 2

检查这个，可能会有所帮助并可能解决您的问题。如果这不能解决您的问题，至少您可以摆脱 Lint 错误。 Lint error “Do not treat position as fixed; only use immediately…”。所以无论你在哪里使用 final int position** 将其更改为 getAdapterPosition();

The documentation of RecyclerView.Adapter.onBindViewHolder() states:

Note that unlike ListView, RecyclerView will not call this method again if the position of the item changes in the data set unless the item itself is invalidated or the new position cannot be determined. For this reason, you should only use the position parameter while acquiring the related data item inside this method and should not keep a copy of it. If you need the position of an item later on (e.g. in a click listener), use getAdapterPosition() which will have the updated adapter position

So, technically items may be re-arranged and binding will not be necessary because items are not invalidated yet. The position variable received holds true only for the scope of bind function and will not always point to correct position in the data set. That's why the function getAdapterPosition() must be called everytime updated position is needed.

IMHO, mLastPosition = holder.getAdapterPosition(); is still potentially wrong. Because item may be re-arranged and mLastPosition still points to old position.

About why lint is silent, perhaps Lint rule is not that thorough. Its only checking whether position parameter is being copied or not.

在 RecyclerView 中获取微调器选择的项目

Get spinner selected item inside RecyclerView

android

android-spinner

android-recyclerview