通过在Android中单击地图OpenStreetMap设置标记

Question

如何在Android或Xamarin.Android中的开放街道地图上单击地图并添加书签

Answer 1

The XML layout for maps activity also have a search edit text to search places using google maps. The XML layout for maps activity should contain

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent">

    <TextView android:id="@+id/addressTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".AppComponents.Activities.LocationPickerActivity" />

    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="4dp"
        android:paddingTop="4dp"
        card_view:cardElevation="4dp"
        card_view:cardMaxElevation="4dp"
        card_view:cardUseCompatPadding="true"
        card_view:cardCornerRadius="4dp">
    <fragment
        android:id="@+id/place_autocomplete_fragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:name="com.google.android.gms.location.places.ui.PlaceAutocompleteFragment"
        />
    </android.support.v7.widget.CardView>

    <Button
        android:id="@+id/locationSetButton"
        android:layout_width="wrap_content"
        android:elevation="8dp"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_marginBottom="17dp"
        android:layout_marginStart="27dp"
        android:text="Set Location" />


</RelativeLayout>

And in LocationPicker.java class you have to declare a variable of Marker&GoogleMap type.

package com.app1.myapplication.AppComponents.Activities;

import android.app.Activity;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.GooglePlayServicesNotAvailableException;
import com.google.android.gms.common.GooglePlayServicesRepairableException;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.places.Place;
import com.google.android.gms.location.places.Places;
import com.google.android.gms.location.places.ui.PlaceAutocomplete;
import com.google.android.gms.location.places.ui.PlaceAutocompleteFragment;
import com.google.android.gms.location.places.ui.PlacePicker;
import com.google.android.gms.location.places.ui.PlaceSelectionListener;
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.LatLngBounds;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.app1.myapplication.R;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;

public class LocationPicker extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;
    Marker markerLocation;
    private GoogleApiClient mGoogleApiClient;
    private FusedLocationProviderClient mFusedLocationClient;
    private LocationRequest mLocationRequest;
    private LocationCallback mLocationCallback;
    double a,b;
    Place place;
    LatLng finalLocation;

    private LatLngBounds.Builder mBounds = new LatLngBounds.Builder();

    private void addPointToViewPort(LatLng newPoint) {
        mBounds.include(newPoint);
        mMap.animateCamera(CameraUpdateFactory.newLatLngBounds(mBounds.build(),
                findViewById(R.id.addressTextView).getHeight()));
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1) {
            if (resultCode == Activity.RESULT_OK) {
                place = PlacePicker.getPlace(this, data);

                PlaceAutocomplete.getPlace(this,data);
            } else if (resultCode == PlacePicker.RESULT_ERROR) {
                Toast.makeText(this, "Places API failure! Check that the API is enabled for your key",
                        Toast.LENGTH_LONG).show();
            }
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
        try {
            Intent intent = new PlaceAutocomplete.IntentBuilder(PlaceAutocomplete.MODE_OVERLAY).build(this);
            startActivityForResult(intent,1);
        }
        catch (GooglePlayServicesRepairableException e){
        }
        catch (GooglePlayServicesNotAvailableException e){
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location_picker);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(Places.GEO_DATA_API)
                .build();
        mGoogleApiClient.connect();

        View locationButton = ((View) findViewById(Integer.parseInt("1")).getParent()).findViewById(Integer.parseInt("2"));
        RelativeLayout.LayoutParams rlp = (RelativeLayout.LayoutParams) locationButton.getLayoutParams();
// position on right bottom
        rlp.addRule(RelativeLayout.ALIGN_PARENT_TOP, 0);
        rlp.addRule(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.TRUE);
        rlp.setMargins(0, 1500, 30, 20);

        PlaceAutocompleteFragment autocompleteFragment = (PlaceAutocompleteFragment)
                getFragmentManager().findFragmentById(R.id.place_autocomplete_fragment);

        //Task<AutocompletePredictionBufferResponse> results=Places.GeoDataApi.getAutocompletePredictions()
        autocompleteFragment.setOnPlaceSelectedListener(new PlaceSelectionListener() {
            @Override
            public void onPlaceSelected(Place place2) {
               place=place2;
               finalLocation=place2.getLatLng();
               mMap.moveCamera(CameraUpdateFactory.newLatLng(place2.getLatLng()));
                mMap.animateCamera(CameraUpdateFactory.zoomTo(17));
                try{
                    mMap.setMyLocationEnabled(true);
                }
                catch(SecurityException e){

                }
                // TODO: Get info about the selected place.
                //Log.i(TAG, "Place: " + place.getName());
            }

            @Override
            public void onError(Status status) {
                // TODO: Handle the error.
                //Log.i(TAG, "An error occurred: " + status);
            }
        });

        Button locationSetButton=(Button)findViewById(R.id.locationSetButton);
        locationSetButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                LatLng msd=finalLocation;
                //getCallingActivity();
                Geocoder geocoder=new Geocoder(LocationPickerActivity.this, Locale.getDefault());
                List<Address> nearByList=null;
                try {
                    nearByList = geocoder.getFromLocation(finalLocation.latitude,finalLocation.longitude , 1);
                }
                catch (IOException e){

                }
                Intent intent=new Intent();
                double[] geoCoordinates=new double[2];
                geoCoordinates[0]=msd.latitude;
                geoCoordinates[1]=msd.longitude;

                JSONObject userJSONObject=new JSONObject();
                JSONArray userJSONArray=new JSONArray();
                try {
                    Geocoder geocoder2=new Geocoder(LocationPickerActivity.this, Locale.getDefault());
                    List<Address> nearByList2=null;
                    HashSet<String> ls2=new HashSet<String>();
                    try {
                        nearByList = geocoder.getFromLocation(msd.latitude, msd.longitude, 1);
                    }
                    catch (IOException e){

                    }
                    Address ad2=nearByList.get(0);
                    ls2.add(ad2.getPostalCode());

                    DecimalFormat decimalFormat=new DecimalFormat("#.#####");
                    double x=Double.parseDouble(decimalFormat.format(msd.latitude));
                    double y=Double.parseDouble(decimalFormat.format(msd.longitude));
                    userJSONObject.put("Latitude", x);
                    userJSONObject.put("Longitude", y);
                    userJSONObject.put("GoogleAddressLine",ad2.getAddressLine(0));
                    userJSONObject.put("zipCode",ad2.getPostalCode());
                    userJSONObject.put("city",ad2.getLocality());
                    userJSONObject.put("state",ad2.getAdminArea());
                    userJSONObject.put("country",ad2.getCountryName());
                }
                catch (JSONException e){

                }
                userJSONArray.put(userJSONObject);
                String data=userJSONObject.toString();

                String loc=String.valueOf(geoCoordinates[0])+" * "+String.valueOf(geoCoordinates[1]);
                intent.putExtra("locationCoordinates",geoCoordinates);

                File locationFile=new File(getApplicationContext().getFilesDir(),"localLocationFile.txt");
                try {
                    FileOutputStream fos = new FileOutputStream(locationFile);
                    fos.write(data.getBytes());
                    fos.close();
                }
                catch (IOException e){

                }
                finish();
            }
        });

    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        final TextView textView=(TextView)findViewById(R.id.addressTextView);
        textView.getViewTreeObserver().addOnGlobalLayoutListener(
                new ViewTreeObserver.OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        mMap.setPadding(0, textView.getHeight(), 0, 0);
                    }
                }
        );

        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
            @Override
            public void onMapClick(LatLng latLng) {
                finalLocation=latLng;
                MarkerOptions markerOptions=new MarkerOptions();
                markerOptions.position(latLng);
                mMap.clear();
                mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng,15));
                mMap.addMarker(markerOptions);
            }
        });

        mFusedLocationClient= LocationServices.getFusedLocationProviderClient(this);
        mLocationRequest=new LocationRequest();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_LOW_POWER);


        mLocationCallback=new LocationCallback(){
            @Override
            public void onLocationResult(LocationResult locationResult)
            {
                if(locationResult==null){
                    return;
                }
                for(Location location : locationResult.getLocations())
                {
                    a=location.getLatitude();
                    b=location.getLongitude();
                    LatLng ll=new LatLng(a,b);
                    finalLocation=ll;
                    addPointToViewPort(ll);

                    markerLocation=mMap.addMarker(new MarkerOptions().position(ll).draggable(true));
                    mMap.moveCamera(CameraUpdateFactory.newLatLng(ll));
                    mMap.animateCamera(CameraUpdateFactory.zoomTo(17));
                    try{
                    mMap.setMyLocationEnabled(true);
                    }
                    catch(SecurityException e){

                    }

                    Geocoder geocoder=new Geocoder(LocationPickerActivity.this, Locale.getDefault());
                    List<Address> nearByList=null;
                    HashSet<String> ls=new HashSet<String>();
                    try {
                        nearByList = geocoder.getFromLocation(a, b, 1);
                    }
                    catch (IOException e){

                    }
                    Address ad=nearByList.get(0);
                    ls.add(ad.getPostalCode());
                }
            }
        };

        try {
            mFusedLocationClient.requestLocationUpdates(mLocationRequest, mLocationCallback, null);
        }
        catch (SecurityException e){

        }

    }
}

Answer 2

Are you using a special library for showing osm map? or trying to load map on a web view?

If you don't use any special library you can use OSMSHARP and using this codes you can add OSM map to your Xamarin.Android or Xamarin.ios projects:

Native.Initialize();

    var _mapView = new MapView(View.Frame);
    _mapView.MapCenter = new GeoCoordinate(52.207767, 8.803513);
    _mapView.MapZoom = 12;
    _mapView.Map.AddLayerTile("http://a.tile.openstreetmap.de/tiles/osmde/{0}/{1}/{2}.png");

    View.AddSubview(_mapView);

this code will add mapView to your root view.

if you have more question you can contact with package owner.

another solution is using web view for showing osm map. first you should add a web view to your activity, then you should add Javascript interface classes to your solution, using this class you can save interactions on your device.

first we define a class that we want to use as or javascript interface:

 class MyJSInterface : Java.Lang.Object, Java.Lang.IRunnable
 {
    Context context;

    public MyJSInterface (Context context)
    {
        this.context = context;
    }

    public void AddNewPlace()
    {
        Toast.MakeText(context, "Hello from C#", ToastLength.Short).Show();
    }
}

the next step is to define a web view in activity and bind this class as interface for web view

WebView webView = new WebView(this);
SetContentView(webView);

webView.Settings.JavaScriptEnabled = true;
webView.AddJavascriptInterface(new MyJSInterface(this), "deviceInterface");
webView.LoadData("PATH TO OSM PAGE THAT HOSTED IN SERVER", "text/html", null);

this is a simple example of html page that we will load into webView and how we call c# methods from page:

 <html>
   <body>
     <p>calling C# methods from JavaScript</p>
     <button type=""button"" onClick=""deviceInterface.AddNewPlace()"">Add Custom Marker or anything else</button>
   </body>
 </html>

now we can call this interface class methods from javascript: