getLastLocation() 返回俄罗斯中部的随机位置

Posted 2023-04-14

【中文标题】getLastLocation() 返回俄罗斯中部的随机位置

【英文标题】：getLastLocation() returns a random location in the middle of russia

【发布时间】：2021-01-17 05:20:09

【问题描述】：

我试图通过 SMS 向用户发送最后知道的位置，但 lastKnownLocation() 不断返回 null 或随机位置，位于俄罗斯海岸附近的偏远地区，感谢任何帮助！ 我早些时候试图通过 LocationManager 获取位置，但后来开始每次都重新调整 null。 我正在遵循文档中给出的步骤 https://developer.android.com/training/location/retrieve-current

package com.r30.wec_task;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import android.Manifest;
import android.app.PendingIntent;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;


import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

public class SosActivity extends AppCompatActivity 
    private static final int REQUEST_LOCATION = 1;
    private static final int REQUEST_SMS = 1;
    private FusedLocationProviderClient fusedLocationClient;

    FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
    DatabaseReference userRef = FirebaseDatabase.getInstance().getReference("users").child(user.getUid());
   // LocationManager locationManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sos2);
        ActivityCompat.requestPermissions( this,
                new String[] Manifest.permission.ACCESS_FINE_LOCATION, REQUEST_LOCATION);
        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);


    
    String emergencyContactNo;
    @Override
    protected void onStart() 
        super.onStart();
        ImageButton sosBtn = findViewById(R.id.sosButton);
        //Get Emergency Contact from DataBase
        userRef.addValueEventListener(new ValueEventListener() 
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) 
                emergencyContactNo = snapshot.child("eContact").getValue(String.class).toString();
                Toast.makeText(SosActivity.this,emergencyContactNo,Toast.LENGTH_SHORT);

            

            @Override
            public void onCancelled(@NonNull DatabaseError error) 
                Toast.makeText(SosActivity.this,"Error getting your emergency contact",Toast.LENGTH_SHORT);
            
        );
        //Button Click sends SOS signal + GPS Co-ordinates
        sosBtn.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                //get Location of user
                LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) 
                    OnGPS();
                 else 
                    sendLocation();
                
            
        );
    
    private void OnGPS() 
        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("Enable GPS").setCancelable(false).setPositiveButton("Yes", new  DialogInterface.OnClickListener() 
            @Override
            public void onClick(DialogInterface dialog, int which) 
                startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
            
        ).setNegativeButton("No", new DialogInterface.OnClickListener() 
            @Override
            public void onClick(DialogInterface dialog, int which) 
                dialog.cancel();
            
        );
        final AlertDialog alertDialog = builder.create();
        alertDialog.show();
    
    String ans;
    private void sendLocation() 
        if (ActivityCompat.checkSelfPermission(
                SosActivity.this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
                SosActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) 
            ActivityCompat.requestPermissions(this, new String[]Manifest.permission.ACCESS_FINE_LOCATION, REQUEST_LOCATION);
         else 
            fusedLocationClient.getLastLocation()
                    .addOnSuccessListener(this, new OnSuccessListener<Location>() 
                        @Override
                        public void onSuccess(Location location) 
                            // Got last known location. In some rare situations this can be null.
                            if (location != null) 
                                // Logic to handle location object
                                ans=location.getLongitude()+","+location.getLongitude();
                                Intent intent=new Intent(SosActivity.this,SosActivity.class);
                                PendingIntent pi=PendingIntent.getActivity(getApplicationContext(), 0, intent,0);
                                //Get the SmsManager instance and call the sendTextMessage method to send message
                                SmsManager sms=SmsManager.getDefault();
                                sms.sendTextMessage(emergencyContactNo, null, "SOS my location is http://maps.google.com/maps?q="+ans, pi,null);
                                Toast.makeText(getApplicationContext(), "Message Sent successfully!"+emergencyContactNo,
                                        Toast.LENGTH_LONG).show();
                            
                        
                    );
        
    

【参考方案1】：

您使用了两次经度：

ans=location.getLongitude()+","+location.getLongitude();

应该是：

ans=location.getLatitude()+","+location.getLongitude();

【讨论】：

非常感谢！！我已经让 7 个人检查了我的代码，不敢相信没有人发现这个。