Spin ner OnItemSelected在Android Studio中不起作用[关闭]

Question

我可以查看微调器项目，但onItemSelected方法无效。其他文本数据不显示，该怎么办？

我有微调器，它显示用户的名称，我试图按微调器项目显示其他三个文本框数据，但Textview上没有数据显示。

我不知道是什么。

 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Spinner;

 import android.widget.TextView;

 import com.android.volley.RequestQueue;
 import com.android.volley.Response;
 import com.android.volley.VolleyError;
 import com.android.volley.toolbox.StringRequest;
 import com.android.volley.toolbox.Volley;

 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;

 import java.util.ArrayList;
 import android.widget.AdapterView.OnItemSelectedListener;
 import android.view.View.OnClickListener;

 public class Search extends AppCompatActivity implements AdapterView.OnItemSelectedListener 

  private Spinner spinner;
  private ArrayList<String> students;
  private JSONArray result;
  private TextView textViewName;
  private TextView textViewCourse;
  private TextView textViewSession;

  @Override
  protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_search);
    students = new ArrayList<String>();
    spinner = (Spinner) findViewById(R.id.myspinner);
   // spinner.setOnItemSelectedListener(this);
    textViewName = (TextView) findViewById(R.id.txtName);
    textViewCourse = (TextView) findViewById(R.id.txtBussy);
    textViewSession = (TextView) findViewById(R.id.txtAdd);
    getData();


  

  private void getData()
     StringRequest stringRequest = new 
   StringRequest("https://maheshwaghela.com/RukhiVivah/RetrivesData/spinner1.php",
            new Response.Listener<String>() 
                @Override
                public void onResponse(String response) 
                    JSONObject j = null;
                    try 
                        j = new JSONObject(response);
                        result = j.getJSONArray(Config.JSON_ARRAY);
                        getStudents(result);
                     catch (JSONException e) 
                        e.printStackTrace();
                    
                
            ,
            new Response.ErrorListener() 
                @Override
                public void onErrorResponse(VolleyError error) 

                
            );
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);

   

   private void getStudents(JSONArray j)
    for(int i=0;i<j.length();i++)
        try 
            JSONObject json = j.getJSONObject(i);
            students.add(json.getString(Config.TAG_USERNAME));
         catch (JSONException e) 
            e.printStackTrace();
        
    
    spinner.setAdapter(new ArrayAdapter<String>(Search.this, android.R.layout.simple_spinner_dropdown_item, students));
 

//Method to get student name of a particular position
private String getName(int position)
    String name="";
    try 
        //Getting object of given index
        JSONObject json = result.getJSONObject(position);

        //Fetching name from that object
        name = json.getString(Config.TAG_NAME);
     catch (JSONException e) 
        e.printStackTrace();
    
    //Returning the name
    return name;


//Doing the same with this method as we did with getName()
private String getCourse(int position)
    String bussy="";
    try 
        JSONObject json = result.getJSONObject(position);
        bussy = json.getString(Config.TAG_BUSSY);
     catch (JSONException e) 
        e.printStackTrace();
    
    return bussy;


//Doing the same with this method as we did with getName()
private String getSession(int position)
    String address="";
    try 
        JSONObject json = result.getJSONObject(position);
        address = json.getString(Config.TAG_ADDRESS);
     catch (JSONException e) 
        e.printStackTrace();
    
    return address;



   //this method will execute when we pic an item from the spinner
  //  @Override
  public void onItemSelected(AdapterView<?> parent, View view, int position, long id) 
    //Setting the values to textviews for a selected item
    textViewName.setText(getName(position));
    textViewCourse.setText(getCourse(position));
    textViewSession.setText(getSession(position));
 

 //When no item is selected this method would execute
 // @Override
 public void onNothingSelected(AdapterView<?> parent) 
    textViewName.setText("");
    textViewCourse.setText("");
    textViewSession.setText("");

为什么onItemSelected不起作用。请提供解决方案。