RecyclerView 单选按钮不会只注册最新检查的项目（也记得以前的）

Question

我有 RecyclerView，它有多个项目，这些项目包含单选按钮、课程名称 (TextView) 和孔号 (TextView)。应该发生的是，当我单击单选按钮时，它应该只选择那个 1，如果有之前的检查，它应该取消选中它（单选）。好吧，目前它一次只检查 1 个，这是可以的（因此前端可以正常工作），但是“在引擎盖下”发生了什么......例如：

RecyclerView 目前有 3 个项目。我单击要检查的第三个项目，然后单击第一个，然后再次单击第三个。现在我点击“开始游戏”按钮，应该发生的是它应该采用最后选中的项目（在本例中是最后选择的第三个）并将其课程名称和洞号用于下一个活动，但现在发生的是它意图第一个项目课程名称和洞号......另外，如果我和以前一样，但我没有点击第一个项目，而是点击第二个项目，然后即使最后我点击了第三个项目，而不是意图它的课程名称和孔号，它意味着第二个项目......所以它总是意图被点击的项目（在某个时候）并且从那些被点击的项目中它检查第一个（从列表的顶部到底部）并接受它的意图。

这是我的适配器，我在其中检查选择了哪一个：

public class NewGameCourseAdapter extends RecyclerView.Adapter<NewGameCourseAdapter.NewGameCourseViewHolder> {

    private ArrayList<NewGameCourseItem> mCourseList;

    private NewGamePlayerAdapter.OnItemsCheckStateListener checkStateListener;

private NewGameCourseAdapter.OnItemClickListener itemClickListener;

public void setOnItemClickListener(NewGameCourseAdapter.OnItemClickListener listener) {

    itemClickListener = listener;

}

public interface OnItemClickListener {

    void onItemClick(int position);

}

public void setOnItemsCheckStateListener(NewGamePlayerAdapter.OnItemsCheckStateListener checkStateListener) {

    this.checkStateListener = checkStateListener;

}

public static class NewGameCourseViewHolder extends RecyclerView.ViewHolder {

        public RadioButton mRadioButton;

        public NewGameCourseViewHolder(@NonNull View itemView, final NewGameCourseAdapter.OnItemClickListener listener) {

            super(itemView);

            mRadioButton = itemView.findViewById(R.id.radioButton);

        }

    }

onBindViewHolder:

@Override

    public void onBindViewHolder(@NonNull final NewGameCourseViewHolder holder, final int position) {

        final NewGameCourseItem currentItem = mCourseList.get(position);

        /** This can prevent some unwanted actions in some cases **/

        holder.mRadioButton.setOnCheckedChangeListener(null);

        holder.mRadioButton.setChecked(selectedPosition == position);

摘要：在前端它看起来是正确的，它只选择最后单击的那个单选按钮并取消选中前一个（它应该），但在内部，它不会像它应该做的那样“忘记”以前的选择......

Answer 1

你正在做一些奇怪的事情，如果可能的话让它变得简单。第 1 步：在您的适配器类中创建一个方法来获取所选项目public NewGameCourseItem getSelectedItem() {&nbsp; &nbsp;return mCourseList.get(selectedPosition);}第 2 步：然后修改您的点击方法，如下所示mStartGame.setOnClickListener(new View.OnClickListener() {&nbsp; &nbsp; &nbsp; @Override&nbsp; &nbsp; &nbsp; public void onClick(View view) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;NewGameCourseItem&nbsp; item = adapter.getSelecteditem();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Intent intent = new Intent(ActivityNewGame2.this, ActivityGame.class);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;/** Also intent selected items: course name and hole number **/&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;intent.putExtra("COURSENAME", item.getCourseName());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;intent.putExtra("HOLESNM", item.getHolesNm());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;startActivity(intent);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);&nbsp; &nbsp; &nbsp; }&nbsp;});第 3 步：现在修改您的 onCheckedChanged 如下&nbsp;public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {&nbsp; &nbsp; &nbsp;notifyItemChanged(selectedPosition);&nbsp; &nbsp; &nbsp;selectedPosition = holder.getAdapterPosition();&nbsp; &nbsp; &nbsp;notifyItemChanged(selectedPosition);&nbsp;}

Answer 2

在适配器中创建一个类变量private int selectedPosition = -1; //change -1 to any default position, need to be selected.修改适配器中的以下功能@Overridepublic void onBindViewHolder(@NonNull final NewGameCourseViewHolder holder, final int position) {&nbsp; &nbsp; final NewGameCourseItem currentItem = mCourseList.get(position);&nbsp; &nbsp; holder.mRadioButton.setChecked(selectedPosition == position);&nbsp; &nbsp; holder.mRadioButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {&nbsp; &nbsp; &nbsp; &nbsp; @Override&nbsp; &nbsp; &nbsp; &nbsp; public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if(isChecked) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int tempSelected = selectedPosition;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; selectedPosition = position;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; notifyDataSetChanged();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; });}在适配器中创建一个新方法，如下所示 -public int getSelectedItemIndex() {&nbsp; &nbsp; return selectedPosition;}我假设是Activity 类中adapter的变量。NewGameCourseAdapter修改Activity中的按钮点击：mStartGame.setOnClickListener(new View.OnClickListener() {&nbsp; &nbsp; @Override&nbsp; &nbsp; public void onClick(View view) {&nbsp; &nbsp; &nbsp; &nbsp; int selectedRecyclerItemPosition = adapter.getSelectedItemIndex();&nbsp; &nbsp; &nbsp; &nbsp; //Calling intent and pass selected item info&nbsp; &nbsp; &nbsp; &nbsp; Intent intent = new Intent(ActivityNewGame2.this, ActivityGame.class);&nbsp; &nbsp; &nbsp; &nbsp; /** Also intent selected items course name and hole number **/&nbsp; &nbsp; &nbsp; &nbsp; intent.putExtra("COURSENAME", mCourseList.get(selectedRecyclerItemPosition).getCourseName());&nbsp; &nbsp; &nbsp; &nbsp; intent.putExtra("HOLESNM", mCourseList.get(selectedRecyclerItemPosition).getHolesNm());&nbsp; &nbsp; &nbsp; &nbsp; startActivity(intent);&nbsp; &nbsp; &nbsp; &nbsp; overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);&nbsp; &nbsp; }});