android - 如何使用字符串地址在 google maps API V2 android 中获取地理坐标？

Question

我正在设计一个定位地点的 Android 应用程序，这些地点位于服务器的数据库中，但我只有地点的名称和位置，所以我需要在我的应用程序中找到它并放置一个 标记在那里。仅通过地址获取坐标是可能的，或者，我是否需要重做我的数据库，添加带有纬度和经度的字段？

Answer 1

您可以使用 Geocoder类查找您拥有的地址，然后使用返回的 LanLng 对象用标记填充 map 。

请注意，Geocoder 类无法对每个地址进行地理编码，但如果格式正确，则大多数地址都能成功。

从 this question 获取代码作为指导，我刚刚让这个简单的例子开始工作。

我创建了一个自定义类来存储位置名称、位置地址和一个 LatLng 对象来存储纬度/经度。

对于这个简单的例子，我只使用了三个地址。

这里是完整的类代码:

import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

public class MapsActivity extends AppCompatActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

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

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


    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }


    private void setUpMap() {
        mMap.setMyLocationEnabled(true);

        List<CustomLocation> custLocs = new ArrayList<CustomLocation>();

        //Testing with three addresses
        custLocs.add(new CustomLocation("location 1", "100 market street san francisco ca"));
        custLocs.add(new CustomLocation("location 2", "200 market street san francisco ca"));
        custLocs.add(new CustomLocation("location 3", "300 market street san francisco ca"));


        //set the location for each item in the list
        for (CustomLocation custLoc : custLocs){
            custLoc.setLocation(getSingleLocationFromAddress(custLoc.address));
        }

        //draw the Marker for each item in the list
        for (CustomLocation custLoc : custLocs){
            mMap.addMarker(new MarkerOptions().position(custLoc.latLng)
                    .title(custLoc.name).icon(BitmapDescriptorFactory
                    .defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)));
        }
    }

    //method to do a lookup on the address
    public LatLng getSingleLocationFromAddress(String strAddress)
    {
        Geocoder coder = new Geocoder(this, Locale.getDefault());
        List<Address> address = null;
        Address location = null;
        LatLng temp = null;
        String strAddresNew = strAddress.replace(",", " ");
        try
        {
            address = coder.getFromLocationName(strAddresNew, 1);
            if (!address.isEmpty())
            {
                location = address.get(0);
                location.getLatitude();
                location.getLongitude();
                temp = new LatLng(location.getLatitude(), location.getLongitude());
                Log.d("Latlng : ", temp + "");
            }
        } catch (IOException e)
        {
            Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
            e.printStackTrace();
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        return temp;
    }

    //class to hold the name and address and location
    public static class CustomLocation{

        public String name;
        public String address;
        public LatLng latLng;
        public CustomLocation(String n, String a){
            name = n;
            address = a;
        }
        public void setLocation(LatLng ll){
            latLng = ll;
        }
    }
}

结果: