如何使用坐标在地图上查找位置 android

Question

我正在 Java 使用 Google Api 服务构建地图。目前我的地图接受一个地址，然后在我的地图上找到并标记位置。我希望它能够获取坐标并找到这些坐标的位置并对其进行标记，但还没有找到向我展示如何这样做的文档。谁能指出我正确的方向？谢谢 :)

这是我的地图的图像，可以提供某种可视化效果 !https://imgur.com/a/Aq85U

我需要它从我的搜索栏和地图上的 locate/mark 区域获取 Lat/Long。到目前为止，这是我的地图应用程序代码

package net.androidbootcamp.mymapdemo;

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationProvider;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

/**
 * Created by Micha on 3/1/2018.
 */

public class MapActivity extends AppCompatActivity implements OnMapReadyCallback {

    @Override
    public void onMapReady(GoogleMap googleMap) {
        Toast.makeText(this, "Map is Ready", Toast.LENGTH_SHORT).show();
        Log.d(TAG, "onMapReady: Map is Ready");
        mMap = googleMap;

        if (mLocationPermissionsGranted) {
            getDeviceLocation();

            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                    != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                return;
            }
            mMap.setMyLocationEnabled(true);
            mMap.getUiSettings().setMyLocationButtonEnabled(false);

            init();
        }
    }

    private static final String TAG = "MapActivity";
    private static final String FINE_LOCATION = Manifest.permission.ACCESS_FINE_LOCATION;
    private static final String COURSE_LOCATION = Manifest.permission.ACCESS_COARSE_LOCATION;
    private static final int LOCATION_PERMISSION_REQUEST_CODE = 1234;
    private static final float DEFAULT_ZOOM = 15f;


    //Widget
    private EditText mSearchText;
    private ImageView mGps;

    //Variables
    private Boolean mLocationPermissionsGranted = false;
    private GoogleMap mMap;
    private FusedLocationProviderClient mFusedLocationProviderClient;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_map);
        getLocationPermission();
        mSearchText =(EditText) findViewById(R.id.input_search);
        mGps = (ImageView) findViewById(R.id.ic_gps);

    }

    private void init(){
        Log.d(TAG, "init: initializing");

        mSearchText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView textViewv, int actionId, KeyEvent keyEvent) {
                if (actionId == EditorInfo.IME_ACTION_SEARCH
                        || actionId == EditorInfo.IME_ACTION_DONE
                        || keyEvent.getAction() == KeyEvent.ACTION_DOWN
                        || keyEvent.getAction() == KeyEvent.KEYCODE_ENTER){

                    //Execute method for searching
                    geoLocate();

                }

                return false;
            }
        });

        mGps.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d(TAG,"onClick: clicked gps icon");
                getDeviceLocation();
            }
        });

        hideSoftKeyboard();
    }

    private void geoLocate(){
        Log.d(TAG,"geoLocate: geolocating");
        String searchString = mSearchText.getText().toString();

        Geocoder geocoder = new Geocoder(MapActivity.this);
        List<Address> list = new ArrayList<>();
        try {
            list = geocoder.getFromLocationName(searchString, 1);
        }catch (IOException e){
            Log.e(TAG,"geoLocate: IOException:" + e.getMessage());
        }

        if (list.size() > 0){
            Address address = list.get(0);

            Log.d(TAG,"geoLocate: found a location: " + address.toString());
            //Toast.makeText(this, address.toString(), Toast.LENGTH_SHORT).show();

            moveCamera(new LatLng(address.getLatitude(),address.getLongitude()),DEFAULT_ZOOM, address.getAddressLine(0));
        }
    }

    private void getDeviceLocation(){
        Log.d(TAG,"getDeviceLocation: getting the devices current location");

        mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);

        try {
            if (mLocationPermissionsGranted){
                Task location = mFusedLocationProviderClient.getLastLocation();
                location.addOnCompleteListener(new OnCompleteListener() {
                    @Override
                    public void onComplete(@NonNull Task task) {
                        if (task.isSuccessful()){
                            Log.d(TAG,"onComplete: found location!");
                            Location currentLocation = (Location) task.getResult();

                            moveCamera(new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude()), DEFAULT_ZOOM,"My Location");
                        }else {
                            Log.d(TAG,"onComplete: current location is null");
                            Toast.makeText(MapActivity.this, "unable to get current location", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        }catch (SecurityException e){
            Log.e(TAG,"getDeviceLocation: SecurityException: " + e.getMessage());
        }
    }

    private void moveCamera(LatLng latLng, float zoom, String title){
        Log.d(TAG, "moveCamera: moving the camera to: lat: " + latLng.latitude + ", lng: " + latLng.longitude);
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,zoom));
        if (!title.equals("My Location")){
            MarkerOptions options = new MarkerOptions()
                    .position(latLng)
                    .title(title)
                    .draggable(true);
            mMap.addMarker(options);
        }
        hideSoftKeyboard();
    }

    private void initMap(){
        Log.d(TAG,"initMap: initializing map");
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

        mapFragment.getMapAsync(MapActivity.this);
    }

    //Checks permissions
    private void getLocationPermission(){
        Log.d(TAG,"getLocationPermission: getting location permissions");
        String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION};

        if (ContextCompat.checkSelfPermission(this.getApplicationContext(),
                FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
            if (ContextCompat.checkSelfPermission(this.getApplicationContext(),
                    COURSE_LOCATION) == PackageManager.PERMISSION_GRANTED){
                mLocationPermissionsGranted = true;
                initMap();
            } else {
                ActivityCompat.requestPermissions(this,
                        permissions,
                        LOCATION_PERMISSION_REQUEST_CODE);
            }
        }else {
            ActivityCompat.requestPermissions(this,
                    permissions,
                    LOCATION_PERMISSION_REQUEST_CODE);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        Log.d(TAG,"onRequestPermissionsResult: called.");

        mLocationPermissionsGranted = false;

        switch (requestCode){
            case LOCATION_PERMISSION_REQUEST_CODE:{
                if(grantResults.length > 0){
                    for (int i = 0; i < grantResults.length; i++){
                        if (grantResults[i] != PackageManager.PERMISSION_GRANTED){
                            mLocationPermissionsGranted = false;
                            Log.d(TAG,"onRequestPermissionsResult: permission failed");
                            return;
                        }
                    }
                    Log.d(TAG,"onRequestPermissionsResult: permission granted");
                    mLocationPermissionsGranted = true;
                    //Initialize map
                    initMap();
                }
            }
        }
    }



    private void hideSoftKeyboard(){
        this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
    }

}

Answer 1

您在搜索坐标时使用了错误的方法。

坐标用这个：

getFromLocation(double latitude, double longitude, int maxResults)

当你有地址时，我们会这样做：

getFromLocationName(String locationName, int maxResults)

请注意一件事，以上这些方法可以 return 多个地址，并且您正在使用 return 列表中的第一个。

Address address = list.get(0);

显然，您不能确定索引 0 处的地址就是所需的地址，即使设置 maxResults=1 也不能保证您将获得所需的地址。因此，您有两个选择，要么在地图上显示所有 return 个地址，要么定义要显示的地址类型的标准，即餐厅、医院等......

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