查找位置：Google Play 位置服务或 Android 平台位置 API

Finding Location : Google Play Location Service or Android platform location APIs

提问by Fazil Uruniyengal

i am trying to get the users location for my new navigation app. i want to check the users location frequently and it has to be accurate . I use the following code from sample to get the location .

我正在尝试获取我的新导航应用程序的用户位置。我想经常检查用户的位置，它必须是准确的。我使用示例中的以下代码来获取位置。

public class MainActivity extends Activity implements LocationListener {
private LocationManager locationManager;
private String provider;
private TextView a;
private TextView b;

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    a = (TextView) findViewById(R.id.a);
    b = (TextView) findViewById(R.id.b);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    Location location = locationManager.getLastKnownLocation(provider);

    if (location != null) {
        System.out.println("Provider " + provider + " has been selected.");
        onLocationChanged(location);
    } else {
        a.setText("Location not available");
        b.setText("Location not available");
    }
}

@Override
protected void onResume() {
    super.onResume();
    locationManager.requestLocationUpdates(provider,0, 1, this);
}

@Override
protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {
    Double lat =  location.getLatitude();
    Double lng =  location.getLongitude();
    a.setText(String.valueOf(lat));
    b.setText(String.valueOf(lng));
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String provider) {
    Toast.makeText(this, "Enabled new provider " + provider,
            Toast.LENGTH_SHORT).show();

}

@Override
public void onProviderDisabled(String provider) {
    Toast.makeText(this, "Disabled provider " + provider,
            Toast.LENGTH_SHORT).show();
}
}

But location cordinates are not updating as i move,i get a constant value always ... is there any better way to get location ? According to to android docs i can use Google Play Location Service or Android platform location APIs for this . I checked the sample code for both and it implements the LocationListener interface to get the user location .So whats the actual difference between them?

但是位置坐标不会随着我的移动而更新，我总是得到一个恒定的值......有没有更好的方法来获取位置？根据 android 文档，我可以为此使用 Google Play 位置服务或 Android 平台位置 API。我检查了两者的示例代码，它实现了 LocationListener 接口以获取用户位置。那么它们之间的实际区别是什么？

回答by nickfox

Absolutely use the new google play location services. They work much better indoors than the old location manager. I have created a sample that uses the new google play location services and works in the background periodically. Check it out:

绝对使用新的 google play 位置服务。他们在室内的工作比旧的位置经理好得多。我创建了一个示例，它使用新的 google play 位置服务并定期在后台工作。一探究竟：

https://github.com/nickfox/GpsTracker/tree/master/phoneClients/android

https://github.com/nickfox/GpsTracker/tree/master/phoneClients/android

回答by Shobhit Puri

When I was working with it, I came across 2 good sources:

当我使用它时，我遇到了两个很好的来源：

1. The blog post: Android Location Fused Provider. It includes a great complete tutorial on using the FusedLocationProviderApito get location in Android.

2. Answers on following Android LocationClient class is deprecated but used in documentationquestion.

1. 博文：Android Location Fused Provider。它包括一个关于使用FusedLocationProviderApi在 Android 中获取位置的完整教程。

2. 不推荐使用以下Android LocationClient 类的答案，但在文档问题中使用。

Basically both talk about the similar steps as mentioned in the Google I/O session, link to which is mentioned in one of the answers:

基本上两者都讨论了 Google I/O 会议中提到的类似步骤，其中一个答案中提到了链接：

• First, to get a GoogleClientApiinstance, like:

  GoogleClientApi googleApiClient = new GoogleApiClient.Builder(locationActivity)
          .addApi(LocationServices.API)
          .addConnectionCallbacks(this)
          .addOnConnectionFailedListener(this)
          .build();
  

• Then to call .connect()on it like:

  googleApiClient.connect();
  

• Then in the callback onConnected, get the last location or even can request the location updates as per your need, eg:

  LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
  

  If you want request location updates, then can use the requestLocationUpdatescall.

• 首先，要获取一个GoogleClientApi实例，例如：

  GoogleClientApi googleApiClient = new GoogleApiClient.Builder(locationActivity)
          .addApi(LocationServices.API)
          .addConnectionCallbacks(this)
          .addOnConnectionFailedListener(this)
          .build();
  

• 然后.connect()像这样调用它：

  googleApiClient.connect();
  

• 然后在回调中onConnected，获取最后一个位置，甚至可以根据您的需要请求位置更新，例如：

  LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
  

  如果你想要请求位置更新，那么可以使用requestLocationUpdates调用。

Hope it helps.

希望能帮助到你。