Question

我是使用微调器的新手，我想在OnCreate中使用getSelectedItemPosition，因为我想在微调器项更改时添加一些过滤，我一直在尝试，但仍然在getSelectedItemPosition中得到NULL，我知道我无法初始化onCreate中的setSpinner但我不知道如何解决它

public class FragmentHistory extends Fragment {

public Spinner spinFilter;
private String[] filterView={"Booking","Success"};
public List<Reservation> getData;
private List<historyView> listHistory;
private RecyclerView myRecycleView;
private ProgressDialog progress;
String URL;
private GetURL getURL=new GetURL(URL);
RecycleViewAdapterHistory recycleViewAdapterHistory;

public FragmentHistory(List<Reservation> getData) {
    this.getData = getData;
}

public FragmentHistory() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view= inflater.inflate(R.layout.fragment_history, container, false);
    setSpinner();

    //Create Recycle view
    myRecycleView=(RecyclerView)view.findViewById(R.id.history_view);
    recycleViewAdapterHistory =new RecycleViewAdapterHistory(getContext(),listHistory);
    myRecycleView.setLayoutManager(new LinearLayoutManager(getActivity()));
    myRecycleView.setAdapter(recycleViewAdapterHistory);

    return view;

}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setSpinner();
    listHistory=new ArrayList<>();
    spinFilter.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            if(spinFilter.getSelectedItemPosition()==0){
                Toast.makeText(getActivity(),"0",Toast.LENGTH_SHORT).show();
                for(int j=0;j<getData.size();j++){
                    //mydata
                }
            }else{
                Toast.makeText(getActivity(),"1",Toast.LENGTH_SHORT).show();
                for(int j=0;j<getData.size();j++){
                    ///mydata
                }
            }
        }

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

        }
    });

}
void setSpinner(){
    spinFilter=(Spinner)getView().findViewById(R.id.spinFilter);
    ArrayAdapter<String> adapterSpinner= new ArrayAdapter<String>(this.getActivity(),android.R.layout.simple_spinner_item,filterView);
    adapterSpinner.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
    spinFilter.setAdapter(adapterSpinner);
}}

Answer 1

你不需要调用getItemSelectedPosition（），因为 int i （onItemSelected的第三个参数）是所选项目的位置。

为微调器添加过滤器以使用RecycleView显示

1 个答案: