java - onItemSelected 的问题

Question

这个问题已经有答案了:

method "onItemSelected" doesn't work in array adapter and also in fragment (2 个回答)

已关闭 6 年前。

为什么 OnItemSelected 不适用于 array adapter ？

我有spinner在 list view 的每一行中。这是我的代码:

package info.androidhive.materialtabs.activity;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

import info.androidhive.materialtabs.R;

/**
 * Created by marco on 24/07/16.
 */

    public  class MyListAdapter extends ArrayAdapter implements AdapterView.OnItemSelectedListener  {
        Spinner spinner;

        /*public MyListAdapter(Context context, int textViewResourceId) {
            super(context, textViewResourceId);
        }*/

        public MyListAdapter(Context context) {
            super(context, R.layout.single_listview_item);
        }





            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                View row = convertView;
                System.out.println("ciao");

                spinner = (Spinner) convertView.findViewById(R.id.simpleSpinner);
                ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                        getContext(),
                        R.array.country_arrays,
                        android.R.layout.simple_spinner_item);
                adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                spinner.setAdapter(adapter);
                spinner.setOnItemSelectedListener(this);

    /*
                spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    */
               /*     @Override
                    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                        //Spinner spinner = null;
                       // String selState = (String) ((Spinner) parent).getSelectedItem();

                        spinner.setSelection(position);
                        String selState = (String) ( parent).getSelectedItem();
                        Toast.makeText(
                                parent.getContext(),
                                "Clicked on Planet: " + selState + "", Toast.LENGTH_SHORT).show();
                    }

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

                    }


                });*/



                return row;
            }

        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            spinner.setSelection(position);
            String selState = (String) ( parent).getSelectedItem();
            Toast.makeText(
                    parent.getContext(),
                    "Clicked on Planet: " + selState + "", Toast.LENGTH_SHORT).show();
        }

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

        }


       /* @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            String selState = (String) spinner.getSelectedItem();
            System.out.println(selState);
            Toast.makeText(
                    getContext(),
                    "Clicked on Planet: " + selState + "", Toast.LENGTH_SHORT).show();
        }

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

        }*/

        }

fragment :

listView = (ListView) rootView.findViewById(R.id.listview);
        ListAdapter listAdapter = new MyListAdapter(getContext());
        listView.setAdapter(listAdapter);

Answer 1

只需在 OnItemSelected 方法中尝试一下...

改变

 String selState = (String) ( parent).getSelectedItem();     

到

 String selState = spinner.getSelectedItem().toString();