Question

好的我正在尝试在Android Studio中实现微调器

这些是我的导入

import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

这是我的java。在这里，我得到了红色的setOnItemSelectedListner，并说无法解析。我正在上面导入它，尽管它正在显示。可能是什么问题。

 Spinner spinner = (Spinner) findViewById(R.id.spinner);
 spinner.setOnItemSelectedListner(this);

整个代码就是这样......

import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.AdapterView.OnItemSelectedListener;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

    }


    Spinner spinner = (Spinner) findViewById(R.id.spinner);

    spinner.setOnItemSelectedListner(this);


    List<String> categories = new ArrayList<String>();
    categories.add("Automobile");
    categories.add("Business Services");
    categories.add("Computers");
    categories.add("Education");
    categories.add("Personal");
    categories.add("Travel");


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


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


    spinner.setAdapter(dataAdapter);
        }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

        String item = parent.getItemAtPosition(position).toString();


        Toast.makeText(parent.getContext(), "Selected: " + item, Toast.LENGTH_LONG).show();
    }
    public void onNothingSelected(AdapterView<?> arg0) {

    }

Answer 1

错字：setOnItemSelectedListner。它应该是setOnItemSelectedListener。

Answer 2

我想你错过了 AdapterView.OnItemSelectedListener

的工具

只需替换此

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,AdapterView.OnItemSelectedListener

而不是

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback

无法解析setOnItemSelectedListener的微调器

2 个答案: