无法使用LocationListener的机器人工作室2.3

Question

我试图获取用户的当前位置，并在日志

这里显示它在日志中显示当前位置我的主要活动的Java代码

import android.Manifest; 
import android.content.Context; 
import android.content.pm.PackageManager; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Build; 
import android.os.Bundle; 
import android.support.annotation.NonNull; 
import android.support.v4.app.ActivityCompat; 
import android.support.v4.content.ContextCompat; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 

public class MainActivity extends AppCompatActivity { 

LocationManager locationManager; 
LocationListener locationListener; 

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

    locationManager = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE); 

    locationListener = new LocationListener() { 
     @Override 
     public void onLocationChanged(Location location) { 

      Log.i("Location",location.toString()); 
     } 

     @Override 
     public void onStatusChanged(String provider, int status, Bundle extras) { 

     } 

     @Override 
     public void onProviderEnabled(String provider) { 

     } 

     @Override 
     public void onProviderDisabled(String provider) { 

     } 
    }; 

    //If the device is running version older than Marshmallow 

    if(Build.VERSION.SDK_INT<23) 
    { 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 
    } 

    else 
    { 
     //Checking if it has permission access 
     if(ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) 
     { 
      //ask for permission 

      ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1); 


     } 
     else 
     { 
      //we have permission 

      locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 
     } 
    } 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
    super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

    if(ContextCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) 
    { 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 
    } 
} 

}

但我没有看到我日志中的销售标签，这里有相应的日志：

Here are My Logs

我是Android新手，因此我不太确定代码出错的位置。

Answer 1

起初，你需要移动LocationListener的onCreate()外：

public class MainActivity extends AppCompatActivity { 

LocationManager locationManager; 
LocationListener locationListener; 

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

    if(Build.VERSION.SDK_INT<23) 
    { 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 
    } 

    else 
    { 
     //Checking if it has permission access 
     if(ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) 
     { 
      //ask for permission 

      ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1); 


     } 
     else 
     { 
      //we have permission 

      locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 
     } 
    } 
} 


    locationListener = new LocationListener() { 
     @Override 
     public void onLocationChanged(Location location) { 

      Log.i("Location",location.toString()); 
     } 

     @Override 
     public void onStatusChanged(String provider, int status, Bundle extras) { 

     } 

     @Override 
     public void onProviderEnabled(String provider) { 

     } 

     @Override 
     public void onProviderDisabled(String provider) { 

     } 
    }; 

    ..... 
} 

然后，修改onRequestPermissionResult()如下：

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
    super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

    switch (requestCode) { 
     case 1: { 
      // If request is cancelled, the result arrays are empty. 
      if (grantResults.length > 0 
        && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
       locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener); 

      } else { 
       Toast.makeText(getApplicationContext(), "Please provide permission.", Toast.LENGTH_LONG).show(); 
      } 
      break; 
     } 
    } 
}