吐司不起作用。选项卡中的微调器

Question

public static class SectionsFragment2 extends Fragment {
    public SectionsFragment2() {}
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_page2, container, false);
        Spinner spinner_device = (Spinner) rootView.findViewById(R.id.spinner_device);
        ArrayAdapter<CharSequence> adapter_device = ArrayAdapter.createFromResource(getActivity(), R.array.array_device, android.R.layout.simple_spinner_item);
            adapter_device.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner_device.setAdapter(adapter_device);
            AdapterView.OnItemSelectedListener listener = new AdapterView.OnItemSelectedListener() {
                public void onItemSelected(AdapterView<?> parent, View view,int pos, long id) {
                  Toast.makeText(parent.getContext(), "OnItemSelected: " + parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
                }
                @Override
                public void onNothingSelected(AdapterView<?> arg0) {
                    //do nothing.
                }
            };
            return rootView;
        }
    }

Answer 1

您没有将OnItemSelectedListener设置为Spinner。试着添加这一行:

spinner_device.setOnItemSelectedListener(listener);