Android 原生定位

有两种定位的方式： 
1.基于GPS定位； 
2.基于网络定位。

GPS定位的 好处 ：精确度高； 坏处 ：仅能在户外使用，获取定位信息速度慢，耗费电池。 
网络定位的 好处 ：户内户外都能使用，定位速度快，电量耗费低； 坏处 ：精确度不太高。

android原生定位框架的核心组件是 
LocationManager 
系统服务，获取这个组件并不需要实例化，通常是通过函数 
getSystemService(Context.LOCATION_SERVICE) 
获得，该函数会返回一个LocationManager的实例，示例代码如下：

// Acquire a reference to the system Location Manager

LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

LocationListener

通过回调（callback）来获取用户定位信息

// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
    public void onLocationChanged(Location location) {
      // Called when a new location is found by the network location provider.
      // 这个函数中的location就是获取到的位置信息
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {}

    public void onProviderEnabled(String provider) {}

    public void onProviderDisabled(String provider) {}
  };    

同时我们需要调用函数  requestLocationUpdates  绑定

// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);

定位权限

定位功能的使用需要获取定位权限 
如果使用 NETWORK_PROVIDER ，那么需要请求

android.permission.ACCESS_COARSE_LOCATION

如果使用 GPS_PROVIDER 或者同时使用上述两种定位方式，那么需要请求

android.permission.ACCESS_FINE_LOCATION

同时，如果你的app的运行环境是Android 5.0（API Level 21）或更高（If your app targets Android 5.0 (API level 21) or higher），那么你还需要显式请求

android.hardware.location.network 
或者 
android.hardware.location.gps

Geocoder可以将一个地址转变为经纬度，或者将经纬度转变为地址。

package com.example.demo;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.text.TextUtils;
import android.text.method.ScrollingMovementMethod;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;

public class LocationActivity extends Activity implements View.OnClickListener {

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

    private LocationManager locationManager;
    private LocationListener locationListener;

    private TextView tv;
    private Button btnStart;
    private Button btnEnd;
    private Button btnClean;

    private StringBuilder stringBuilder = new StringBuilder();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location);
        setTitle("原生定位");

        tv = findViewById(R.id.tv);
        btnStart = findViewById(R.id.btnStart);
        btnEnd = findViewById(R.id.btnEnd);
        btnClean = findViewById(R.id.btnClean);

        btnStart.setOnClickListener(this);
        btnEnd.setOnClickListener(this);
        btnClean.setOnClickListener(this);

        //设置文字太长时TextView可以上下滑动
        tv.setMovementMethod(ScrollingMovementMethod.getInstance());

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                stringBuilder.append(getTime()).append("\t定位信息：\n");
                stringBuilder.append("\t").append(location.getLatitude()).append("\n");
                stringBuilder.append("\t").append(location.getLongitude()).append("\n");
                stringBuilder.append("\t").append(location.getProvider()).append("\n");
                tv.setText(stringBuilder);

                Geocoder gc = new Geocoder(LocationActivity.this, Locale.getDefault());
                List
 locationList = null;
                try {
                    locationList = gc.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Address address = locationList.get(0);//得到Address实例

                if (address == null) {
                    return;
                }

                stringBuilder.append(getTime()).append("\t地址信息：\n");

                String countryName = address.getCountryName();//得到国家名称
                if (!TextUtils.isEmpty(countryName)) {
                    stringBuilder.append(countryName);
                }

                String adminArea = address.getAdminArea();//省
                if (!TextUtils.isEmpty(adminArea)) {
                    stringBuilder.append(adminArea);
                }

                String locality = address.getLocality();//得到城市名称
                if (!TextUtils.isEmpty(locality)) {
                    stringBuilder.append(locality);
                }

                for (int i = 0; address.getAddressLine(i) != null; i++) {
                    String addressLine = address.getAddressLine(i);
                    if(!TextUtils.isEmpty(addressLine)) {
                        if(addressLine.contains(countryName)){
                            addressLine = addressLine.replace(countryName,"");
                        }
                        if(addressLine.contains(adminArea)){
                            addressLine = addressLine.replace(adminArea,"");
                        }
                        if(addressLine.contains(locality)){
                            addressLine = addressLine.replace(locality,"");
                        }
                        if(!TextUtils.isEmpty(addressLine)) {
                            stringBuilder.append(addressLine);
                        }
                    }
                }

                String featureName = address.getFeatureName();//得到周边信息
                if(!TextUtils.isEmpty(featureName)) {
                    stringBuilder.append(featureName).append("\n");
                }
                tv.setText(stringBuilder);
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        };

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnStart:
                stringBuilder.append(getTime()).append("\t开始定位\n");
                tv.setText(stringBuilder);
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_DENIED) {
                    return;
                }
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_DENIED) {
                    return;
                }
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
                locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
                break;
            case R.id.btnEnd:
                locationManager.removeUpdates(locationListener);
                stringBuilder.append(getTime()).append("\t结束定位\n\n");
                tv.setText(stringBuilder);
                break;
            case R.id.btnClean:
                stringBuilder.delete(0, stringBuilder.length());
                tv.setText(stringBuilder);
                break;
            default:
                break;
        }
    }

    private String getTime() {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss", Locale.getDefault());
        return simpleDateFormat.format(new Date(System.currentTimeMillis()));
    }
}