如何解决Android Spinner setOnItemSelectedListener 不会触发,但它会显示来自 API
Spinner 有问题。我使用 Volley 从 API 下载数据并将其放入 Spinner。我可以看到我从 API 获得的所有项目。但是我不能选择它,spinner setonItemSelectedListener 也不会触发(没有日志,没有敬酒)。 来自 getDataFromAPI() 的日志效果很好,所有数据都从源正确下载。
您可以在下面看到代码。
感谢您的帮助。
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolBox.JsonArrayRequest;
import com.android.volley.toolBox.Volley;
import com.example.plantapp.Model.WeatherStation;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class StationUser extends AppCompatActivity {
private Spinner stationUserSpinnerStation,stationUserSpinnerConfirm;
private String IMGW_URL = "https://danepubliczne.imgw.pl/api/data/synop";
private ArrayList<WeatherStation> WeatherList = new ArrayList<>();
private List<String> StationList = new ArrayList<>();
private RequestQueue mQueue;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_station_user);
stationUserSpinnerStation = findViewById(R.id.stationUserSpinnerStation);
mQueue = Volley.newRequestQueue(this);
getDataFromAPI();
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(this,android.R.layout.simple_spinner_item,StationList);
arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
stationUserSpinnerStation.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();
stationUserSpinnerStation.setonItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent,View view,int position,long id) {
String spinnerValue = parent.getItemAtPosition(position).toString();
stationUserSpinnerStation.setSelection(position);
Log.d("saodjawduiaw",spinnerValue + " " + position + " " + id + "\n\n");
Toast.makeText(StationUser.this,"Selected item" + spinnerValue,Toast.LENGTH_SHORT).show();
arrayAdapter.notifyDataSetChanged();
}
@Override
public void onnothingSelected(AdapterView<?> parent) {
Toast.makeText(StationUser.this,"Selected item",Toast.LENGTH_SHORT).show();
}
});
}
private void getDataFromAPI() {
JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET,IMGW_URL,null,new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
try {
for (int i = 0; i < response.length(); i++) {
JSONObject station = response.getJSONObject(i);
String stacja = station.getString("stacja");
double temperatura = station.getDouble("temperatura");
double suma_opadu = station.getDouble("suma_opadu");
WeatherStation tempstation = new WeatherStation(stacja,temperatura,suma_opadu);
WeatherList.add(tempstation);
StationList.add(stacja);
Log.d("info",stacja + " " + temperatura + " " + suma_opadu + "\n\n");
Log.d("stacja",tempstation.getStation() + tempstation.getTemperature() + tempstation.getRainfall());
}
} catch (JSONException e) {
e.printstacktrace();
}
}
},new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printstacktrace();
}
});
mQueue.add(request);
}
}
解决方法
试试这样,将arrayadapter定义为全局变量然后在onCreate方法中初始化arrayadapter,然后调用arrayAdapter.notifyDataSetChanged( ); 在 onResponse 方法中
public class StationUser extends AppCompatActivity {
private Spinner stationUserSpinnerStation,stationUserSpinnerConfirm;
private String IMGW_URL = "https://danepubliczne.imgw.pl/api/data/synop";
private ArrayList<WeatherStation> WeatherList = new ArrayList<>();
private List<String> StationList = new ArrayList<>();
private RequestQueue mQueue;
ArrayAdapter<String> arrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
stationUserSpinnerStation = findViewById(R.id.stationUserSpinnerStation);
mQueue = Volley.newRequestQueue(this);
getDataFromAPI();
arrayAdapter = new ArrayAdapter<>(this,android.R.layout.simple_spinner_item,StationList);
arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
stationUserSpinnerStation.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();
stationUserSpinnerStation.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent,View view,int position,long id) {
String spinnerValue = parent.getItemAtPosition(position).toString();
stationUserSpinnerStation.setSelection(position);
Log.d("saodjawduiaw",spinnerValue + " " + position + " " + id + "\n\n");
Toast.makeText(getApplicationContext(),"Selected item" + spinnerValue,Toast.LENGTH_SHORT).show();
arrayAdapter.notifyDataSetChanged();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
Toast.makeText(getApplicationContext(),"Selected item",Toast.LENGTH_SHORT).show();
}
});
}
private void getDataFromAPI() {
JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET,IMGW_URL,null,new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
try {
for (int i = 0; i < response.length(); i++) {
JSONObject station = response.getJSONObject(i);
String stacja = station.getString("stacja");
double temperatura = station.getDouble("temperatura");
double suma_opadu = station.getDouble("suma_opadu");
WeatherStation tempstation = new WeatherStation(stacja,temperatura,suma_opadu);
WeatherList.add(tempstation);
StationList.add(stacja);
Log.d("info",stacja + " " + temperatura + " " + suma_opadu + "\n\n");
Log.d("stacja",tempstation.getData1() + tempstation.getData2() + tempstation.getData3());
arrayAdapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
},new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
mQueue.add(request);
}
}
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