android开发google play服务位置API

Question

我想构建一个应用程序，通过谷歌播放服务为我带来我的位置。 我已经做了所有需要的事情但是我认为它不起作用因为mLastLocation = LocationServices.FusedLocationApi.getLastLocation（mGoogleApiClient）; 返回null，我不知道为什么。我的项目支持谷歌播放服务。

public class MainActivity extends FragmentActivity implements
GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
public static final String TAG = MainActivity.class.getSimpleName();
private Location mLastLocation;
private TextView mLatitudeText;
private TextView mLongitudeText;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mLatitudeText = (TextView) findViewById(R.id.mLatitudeText);
    mLongitudeText = (TextView) findViewById(R.id.mLongitudeText);
    if (mGoogleApiClient == null) {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }
    mLocationRequest = LocationRequest.create()
            .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
            .setInterval(10 * 1000)        // 10 seconds, in milliseconds
            .setFastestInterval(1 * 1000); // 1 second, in milliseconds
}

protected void onStart() {
    super.onStart();
    mGoogleApiClient.connect();

}

protected void onStop() {
    mGoogleApiClient.disconnect();
    super.onStop();
}

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

@Override
protected void onPause() {
    super.onPause();
    if (mGoogleApiClient.isConnected()) {
        LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        mGoogleApiClient.disconnect();
    }
}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
    if (connectionResult.hasResolution()) {
        try {
            // Start an Activity that tries to resolve the error
            connectionResult.startResolutionForResult(this, CONNECTION_FAILURE_RESOLUTION_REQUEST);
        } catch (IntentSender.SendIntentException e) {
            e.printStackTrace();
        }
    } else {
        Log.i(TAG, "Location services connection failed with code " + connectionResult.getErrorCode());
    }
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission
            (this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }
    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null) {
        handleNewLocation(mLastLocation);
    }
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onLocationChanged(Location location) {
    handleNewLocation(location);
}

private void handleNewLocation(Location location) {
    double currentLatitude = location.getLatitude();
    double currentLongitude = location.getLongitude();

}

的build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.example.tazazo.locationgoogleplayservice"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.2.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha7'
    testCompile 'junit:junit:4.12'
    compile 'com.google.android.gms:play-services:10.2.0'
}

的manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.tazazo.locationgoogleplayservice">
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        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>