android: not able to find the location by using FusedLocationApi even after enabling GPS

问题

I'm trying to find the location of the mobile using GPS and FusedLocationApi location. Even after enabling the GPS i'm not getting the location details. Below is the steps i followed. Kindly Help me Out.

Step 1:-

Added the line in my gradle

  compile 'com.google.android.gms:play-services-location:8.1.0'

Step 2:-

MainActivity File

package com.developer.kamalasekar.locationfinder;

import android.location.Location;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {

   private static final String TAG = "MainActivity";
    private TextView mLatitudeTextView;
    private TextView mLongitudeTextView;
    private GoogleApiClient mGoogleApiClient;
    private Location mLocation;
    private LocationRequest mLocationRequest;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mLatitudeTextView = (TextView) findViewById((R.id.latitude_textview));
        mLongitudeTextView = (TextView) findViewById((R.id.longitude_textview));

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    public void onConnected(Bundle bundle) {
        mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);

        if (mLocation != null) {
            mLatitudeTextView.setText(String.valueOf(mLocation.getLatitude()));
            mLongitudeTextView.setText(String.valueOf(mLocation.getLongitude()));
        } else {
            Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
        }
      LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);




    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.i(TAG, "Connection Suspended");
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
    }

    @Override
    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
}

Step3:-

ActivityMain

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/latitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Latitude:"
        android:textSize="18sp" />
    <TextView
        android:id="@+id/latitude_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/latitude"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@+id/latitude"
        android:textSize="16sp" />
    <TextView
        android:id="@+id/longitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Longitude:"
        android:layout_marginTop="24dp"
        android:textSize="18sp" />
    <TextView
        android:id="@+id/longitude_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/longitude"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@+id/longitude"
        android:textSize="16sp"/>

</RelativeLayout>

Step 4:- Added the lines in my manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.developer.kamalasekar.locationfinder">


    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

       </application>

</manifest>

回答1:

There is a possibility that in onConnected if you call LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient); may return null when location not found. But if you execute the same line again after few seconds (1/2 secs and gps enabled ) then you definitely get location for sure.

@Override
public void onConnected(Bundle bundle) {
    mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLocation != null) {
        //your stuff
    } else {
        handler.sendEmptyMessageDelayed(1, 2000);
    }
}

int count;
android.os.Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        if (count < 2) {
            mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
            if (mLocation == null){
                handler.sendEmptyMessageDelayed(1, 2000);
            }else{
                 //your stuff
            }
            count++;
        } else{
            Log.i("MyTag","location not found");
        }
    }
};

or visit Android: Location Updates with the FusedLocationApi
or you can follow @user2450263 post by setting LocationListener.

来源：https://stackoverflow.com/questions/36394695/android-not-able-to-find-the-location-by-using-fusedlocationapi-even-after-enab