我试图使一个应用程序，从mysql数据库的值列表微调器应该只显示名称，然后我会得到这个名称的id移动到其他活动的问题是，微调器不显示任何东西在运行时，即使它的工作很好，当我只运行php页面请我需要帮助这是我的代码

public class ChooseScanActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
    String emailToPass;
    String organizer_ID;
    private Spinner eventSpinner;
    private ArrayList <Event> eventsList;
    ProgressDialog pDialog;
    private String URL_Event = "http://192.168.1.3/Tactic1/list.php?organizer_ID="+organizer_ID;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_choose_scan);
        emailToPass = getIntent().getExtras().getString("emailToPass");
        eventSpinner = (Spinner)findViewById(R.id.spinnerEventID);
        eventsList = new ArrayList<Event>();
        eventSpinner.setOnItemSelectedListener(this);
    }

    private void populateSpinner() {
        List<String> lables = new ArrayList<String>();

        for (int i = 0; i < eventsList.size(); i++) {
            lables.add(eventsList.get(i).getName());
        }

        ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, lables);

        spinnerAdapter
                .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        eventSpinner.setAdapter(spinnerAdapter);

    }

    private class GetEvents extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(ChooseScanActivity.this);
            pDialog.setMessage("get events..");
            pDialog.setCancelable(false);
            pDialog.show();

        }

        @Override
        protected Void doInBackground(Void... arg0) {
            ServiceHandler jsonParser = new ServiceHandler();
            String json = jsonParser.makeServiceCall(URL_Event, ServiceHandler.GET);

            Log.e("Response: ", "> " + json);

            if (json != null) {
                try {
                    JSONObject jsonObj = new JSONObject(json);
                    if (jsonObj != null) {
                        JSONArray frutas = jsonObj
                                .getJSONArray("frutas");

                        for (int i = 0; i < frutas.length(); i++) {
                            JSONObject catObj = (JSONObject) frutas.get(i);
                            Event event = new Event(catObj.getInt("id"),
                                    catObj.getString("nombre"));
                            eventsList.add(event);
                        }
                    }

                } catch (JSONException e) {
                    e.printStackTrace();
                }

            } else {
                Log.e("JSON Data", "¿No ha recibido ningún dato desde el servidor!");
            }

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            if (pDialog.isShowing())
                pDialog.dismiss();
            populateSpinner();
        }

    }

    public void onItemSelected(AdapterView<?> parent, View view, int position,
                               long id) {
        Toast.makeText(
                getApplicationContext(),
                parent.getItemAtPosition(position).toString() + " Seleccionado" ,
                Toast.LENGTH_LONG).show();

    }

    public void onNothingSelected(AdapterView<?> arg0) {
    }

        protected void onResume()
    {
        super.onResume();
        getSqlDetails();
    }

    private void getSqlDetails(){

        String url= "http://192.168.1.3/Tactic1/getOrganizerID.php?emailOrg="+emailToPass;
        StringRequest stringRequest = new StringRequest(Request.Method.GET,
                url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {

                        try {
                            JSONObject jObj = new JSONObject(response);
                            organizer_ID = jObj.getString("organizer_ID");

                            Toast.makeText(getApplicationContext(), organizer_ID, Toast.LENGTH_LONG).show();

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        if(error != null){

                            Toast.makeText(getApplicationContext(), "Something went wrong.", Toast.LENGTH_LONG).show();
                        }
                    }
                }

        );

        MySingleton.getInstance(getApplicationContext()).addToRequestQueue(stringRequest);
    }

        public void onPointerCaptureChanged(boolean hasCapture) {

    }

}

这里是服务处理程序的代码

public class ServiceHandler {

    static InputStream is = null;
    static String response = null;
    public final static int GET = 1;

    public ServiceHandler() {

    }

    /*
     * Making service call
     * @url - url to make request
     * @method - http request method
     * */
    public String makeServiceCall(String url, int method) {
        return this.makeServiceCall(url, method, null);
    }

    /*
     * Making service call
     * @url - url to make request
     * @method - http request method
     * @params - http request params
     * */
    public String makeServiceCall(String url, int method,
                                  List<NameValuePair> params) {
        try {
            // http client
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpEntity httpEntity = null;
            HttpResponse httpResponse = null;

            // Checking http request method type
            if (method == GET) {
                // appending params to url
                if (params != null) {
                    String paramString = URLEncodedUtils
                            .format(params, "utf-8");
                    url += "?" + paramString;
                }
                HttpGet httpGet = new HttpGet(url);

                httpResponse = httpClient.execute(httpGet);

            }
            httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "UTF-8"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            response = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error: " + e.toString());
        }

        return response;

    }
}

这里是事件类的代码

public class Event {

    private int id;
    private String name;

    public Event(){}

    public Event(int id, String name){
        this.setId(id);
        this.setName(name);
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

xml代码

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ChooseScanActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="4dp"
        android:layout_marginLeft="4dp"
        android:text="@string/select_event"
        android:textSize="16sp" />

    <Spinner
        android:id="@+id/spinnerEventID"
        style="@style/Widget.AppCompat.DropDownItem.Spinner"
        android:layout_width="fill_parent"
        android:layout_height="50dp"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="77dp" />

</RelativeLayout>

php代码

<?php
require "conn.php";
$answer = array() ;  
$answer [ "event" ] = array ( ) ;  
$organizer_ID =$_GET['organizer_ID'];

$sql = "select name_Event, event_ID from event where organizer_ID = '$organizer_ID'";

$result = mysqli_query ( $conn , $sql ) ;
while ( $row = mysqli_fetch_array ( $result )){  
$tmp = array () ;  
$tmp ["event_ID"] = $row["event_ID"] ;  
$tmp ["name_Event"] = $row["name_Event"] ;  
array_push ( $answer ["event"] , $tmp ) ;
}
// Keep the response header to json
header ( 'Content-Type: application / json' ) ;
// Listening to json's result
echo json_encode ( $answer ) ; 
?>