在Android中查找用户的当前位置 [英] Finding current location of the user in Android

问题描述

我是Android的新手，我正在尝试开发一个显示用户当前位置的Android应用.我正在使用Genymotion.现在我正在使用

I am new to Android and I am trying to develop an Android app which shows current location of the user. I am using Genymotion. Now I am using

mLocation=LocationServices.FusedLocationApi.getLastLocation(mGoogleClient); 

获取设备的最后位置.事情是我想要获取当前位置，但是有了这个，我得到mlocation的值不是非null就可以了.但是在地图中，它始终显示设备的最后位置，而不是当前位置.

to get the last location of the device. The thing is I wanted to get the current location but with this I get mlocation as not null that's fine. But in the map it shows last location of the device always not the current location.

代码段

@Override
public void onConnected(Bundle bundle) {
    Log.i(TAG, "inside onconnected Location services connected");
    Location mLocation=null;
    mLocationRequest= new LocationRequest();
    mLocationRequest.setInterval(10 * 1000)    ;   
    mLocationRequest.setFastestInterval(1 * 1000);mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) !=
        PackageManager.PERMISSION_GRANTED &&
        ActivityCompat.checkSelfPermission(this,
        Manifest.permission.ACCESS_COARSE_LOCATION) !=
        PackageManager.PERMISSION_GRANTED) {

    }
               mLocation=LocationServices.FusedLocationApi.getLastLocation(mGoogleClient);
    if(mLocation==null)
    {
        Log.d("***Inside mlocation***", "***mlocation is null here");
    }

    if (mLocation != null) {
        onLocationChanged(mLocation);
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleClient, mLocationRequest, this);
}

@Override
public void onLocationChanged(Location location) {
    double currentLatitude = location.getLatitude();
    double currentLongitude = location.getLongitude();
    LatLng latLng = new LatLng(currentLatitude,currentLongitude);
    MarkerOptions options = new MarkerOptions()
            .position(latLng)
            .title("Im here!");

    mMap.addMarker(options);
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
}

，在onstart()中，我打电话给googleapi.connect()，并适当地使用了setUpMapIfNeeded().

and in onstart() I called googleapi.connect() and I used setUpMapIfNeeded() appropriately.

请告诉我这段代码有什么问题.我正在尝试3天.

Please tell me whats the problem in this code. I am trying this for 3 days.

推荐答案

发布带有代码的简单解决方案.

posting simple solution with code.

在AndroidManifest.xml文件中添加权限

add permissions inside AndroidManifest.xml file

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

如果您的应用程序兼容棉花糖，请检查运行时权限.

if you app is marshmallow compatible then check run time permission.

在gradle文件中添加依赖项:

add dependency inside gradle file:

compile 'com.google.android.gms:play-services:9.2.0'

在您的活动中实现这两个界面

implements this two interface in you activity

GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener

和

在oncreate中创建像这样的googleapiclient对象:

create googleapiclient object like this in oncreate:

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

并在开始活动时进行

mGoogleApiClient.connect();

在这里，我们继续执行此覆盖方法上的location的结果回调.

here we go on result callback of location on this override method.

public void onConnected(@Nullable Bundle bundle) {
    Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null) {
        Log.e(TAG, "onConnected: " + String.valueOf(mLastLocation.getLatitude()) + ":" + String.valueOf(mLastLocation.getLongitude()));
    } else {
        Toast.makeText(getApplicationContext(), "Your Location Not Found", Toast.LENGTH_LONG).show();
    }
}

完整的活动代码如下:

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

private static final String TAG = LocationActivity.class.getSimpleName();

private GoogleApiClient mGoogleApiClient;

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


    // Create an instance of GoogleAPIClient.
    if (mGoogleApiClient == null) {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }
}

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

@Override
protected void onStop() {
// disconnect googleapiclient
    mGoogleApiClient.disconnect();
    super.onStop();
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
    if (mLastLocation != null) {
    // here we go you can see current lat long.
        Log.e(TAG, "onConnected: " + String.valueOf(mLastLocation.getLatitude()) + ":" + String.valueOf(mLastLocation.getLongitude()));
    }
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}}

p.s..googleapiclient无法在没有播放服务的模拟器中工作，因此您必须在真实设备上对其进行测试. 请确保在该设备上启用了gps.

p.s. googleapiclient is not working in emulator without play services, so you have to test it on real devices. please make sure gps is enable on that device.

如果要使用传统方法获取位置，请尝试使用本教程. http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/

if you want to use traditional method for get location then try this tutorial. http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/

------更新6月15日---------

获取最新的API 检查android Google帖子: https://android-developers. googleblog.com/2017/06/reduce-friction-with-new-location-apis.html

for latest apis check android google post: https://android-developers.googleblog.com/2017/06/reduce-friction-with-new-location-apis.html

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