[Android & Kotlin] Google Map マーカーの追加

Google Mapの地図上でタップした位置に移動しマーカーを追加してみましょう。基本のGoogle Mapにタップのリスナーや長押しでのリスナーを追加するだけです。

Android Studio
2021.2.1

OnMapClickListener

>Google Maps Activity を選択してプロジェクトを作成すれば、ほとんど出来上がっています。API キーをセットしてください
　
Google Map Activity で地図を表示
　
あとは、OnMapClickListenerのリスナーをセットするだけです。
長押しの場合はOnMapLongClickListenerを使います。

MainActivity.kt

//package your.package.name

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.example.testgmaptapmarker.databinding.ActivityMapsBinding
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.MarkerOptions
import java.util.*

class MapsActivity : AppCompatActivity(), OnMapReadyCallback {

    private lateinit var mMap: GoogleMap
    private lateinit var binding: ActivityMapsBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMapsBinding.inflate(layoutInflater)
        setContentView(binding.root)

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        val mapFragment = supportFragmentManager
            .findFragmentById(R.id.map) as SupportMapFragment
        mapFragment.getMapAsync(this)
    }

    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    override fun onMapReady(googleMap: GoogleMap) {
        mMap = googleMap

        // 皇居辺りの緯度経度
        // 皇居辺りの緯度経度
        var location = LatLng(35.68, 139.76)
        // marker 追加
        // marker 追加
        mMap.addMarker(MarkerOptions().position(location).title("Tokyo"))
        // camera 移動
        // camera 移動
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 10f))

        // タップした時のリスナーをセット
        mMap.setOnMapClickListener { tapLocation: LatLng ->
            // tapされた位置の緯度経度
            location = LatLng(tapLocation.latitude, tapLocation.longitude)
            val str: String =
                java.lang.String.format(
                    Locale.US,
                    "%f, %f",
                    tapLocation.latitude,
                    tapLocation.longitude
                )
            mMap.addMarker(MarkerOptions().position(location).title(str))
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 14f))
        }

        // 長押しのリスナーをセット
        mMap.setOnMapLongClickListener { longpushLocation: LatLng ->
            val newlocation = LatLng(longpushLocation.latitude, longpushLocation.longitude)
            mMap.addMarker(
                MarkerOptions().position(newlocation)
                    .title("" + longpushLocation.latitude + " :" + longpushLocation.longitude)
            )
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(newlocation, 14f))
        }
    }
}

//package your.package.name

import android.os.Bundle

import androidx.appcompat.app.AppCompatActivity

import com.example.testgmaptapmarker.databinding.ActivityMapsBinding

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.MarkerOptions

import java.util.*

class MapsActivity : AppCompatActivity(), OnMapReadyCallback {

private lateinit var mMap: GoogleMap

private lateinit var binding: ActivityMapsBinding

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

binding = ActivityMapsBinding.inflate(layoutInflater)

setContentView(binding.root)

// Obtain the SupportMapFragment and get notified when the map is ready to be used.

val mapFragment = supportFragmentManager

.findFragmentById(R.id.map) as SupportMapFragment

mapFragment.getMapAsync(this)

}

/**

* Manipulates the map once available.

* This callback is triggered when the map is ready to be used.

* This is where we can add markers or lines, add listeners or move the camera. In this case,

* we just add a marker near Sydney, Australia.

* If Google Play services is not installed on the device, the user will be prompted to install

* it inside the SupportMapFragment. This method will only be triggered once the user has

* installed Google Play services and returned to the app.

override fun onMapReady(googleMap: GoogleMap) {

mMap = googleMap

// 皇居辺りの緯度経度

var location = LatLng(35.68, 139.76)

// marker 追加

mMap.addMarker(MarkerOptions().position(location).title("Tokyo"))

// camera 移動

mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 10f))

// タップした時のリスナーをセット

mMap.setOnMapClickListener { tapLocation: LatLng ->

// tapされた位置の緯度経度

location = LatLng(tapLocation.latitude, tapLocation.longitude)

val str: String =

java.lang.String.format(

Locale.US,

"%f, %f",

tapLocation.latitude,

tapLocation.longitude

)

mMap.addMarker(MarkerOptions().position(location).title(str))

mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 14f))

}

// 長押しのリスナーをセット

mMap.setOnMapLongClickListener { longpushLocation: LatLng ->

val newlocation = LatLng(longpushLocation.latitude, longpushLocation.longitude)

mMap.addMarker(

MarkerOptions().position(newlocation)

.title("" + longpushLocation.latitude + " :" + longpushLocation.longitude)

)

mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(newlocation, 14f))

}

local.propertiesに記述

## This file is automatically generated by Android Studio.
...
sdk.dir=C\:\\Users\\akira\\AppData\\Local\\Android\\Sdk

MAPS_API_KEY=AIzaISyBC4N47_xxxxxxxxxxxxxxxxxxxHiRwU

## This file is automatically generated by Android Studio.

...

sdk.dir=C\:\\Users\\akira\\AppData\\Local\\Android\\Sdk

MAPS_API_KEY=AIzaISyBC4N47_xxxxxxxxxxxxxxxxxxxHiRwU

AndroidManifest.xml のYOUR_API_KEY を{MAPS_API_KEY}に置き換え

<meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="${MAPS_API_KEY}" />

<meta-data

android:name="com.google.android.geo.API_KEY"

android:value="${MAPS_API_KEY}" />

実行して、タップをするとマーカーが追加されるのが分かります。
　