使用 Google Maps Platform Navigation SDK 构建简单的 Android 导航应用

val navSdkVersion by extra("6.0.0") 

dependencies {     // Include the Google Navigation SDK.    api("com.google.android.libraries.navigation:navigation:${navSdkVersion}")  ... 

// Top-level build file where you can add configuration options common to all sub-projects/modules. plugins {     id("com.google.android.libraries.mapsplatform.secrets-gradle-plugin") version "2.0.1" apply false     //... other plugin definitions here } 

MAPS_API_KEY=YOUR_API_KEY 

MAPS_API_KEY=DEFAULT_API_KEY 

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

secrets {     // Optionally specify a different file name containing your secrets.     // The plugin defaults to "local.properties"     propertiesFileName = "secrets.properties"      // A properties file containing default secret values. This file can be     // checked in version control.     defaultPropertiesFileName = "local.defaults.properties" } 

<manifest xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools" >    <uses-permission        android:name="android.permission.ACCESS_FINE_LOCATION"    /> </manifest> 

<uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" /> 

    val permissions =       if (VERSION.SDK_INT >= VERSION_CODES.TIRAMISU) {         arrayOf(permission.ACCESS_FINE_LOCATION, permission.POST_NOTIFICATIONS)       } else {         arrayOf(permission.ACCESS_FINE_LOCATION)       }      if (permissions.any { !checkPermissionGranted(it) }) {        if (permissions.any { shouldShowRequestPermissionRationale(it) }) {         // Display a dialogue explaining the required permissions.       }        val permissionsLauncher =         registerForActivityResult(           RequestMultiplePermissions(),           { permissionResults ->             if (permissionResults.getOrDefault(permission.ACCESS_FINE_LOCATION, false)) {               onLocationPermissionGranted()             } else {               finish()             }           },         )        permissionsLauncher.launch(permissions)     } else {       android.os.Handler(Looper.getMainLooper()).postDelayed({ onLocationPermissionGranted() }, SPLASH_SCREEN_DELAY_MILLIS)     }   }    private fun checkPermissionGranted(permissionToCheck: String): Boolean =     ContextCompat.checkSelfPermission(this, permissionToCheck) == PackageManager.PERMISSION_GRANTED 

private fun onLocationPermissionGranted() {    //code to initialize Navigation SDK will go here } 

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent">  <com.google.android.libraries.navigation.NavigationView      android:id="@+id/navigation_view"      android:layout_width="wrap_content"      android:layout_height="wrap_content"       /> </RelativeLayout> 

private lateinit var navView: NavigationView 

navView = findViewById(R.id.navigation_view) navView.onCreate(savedInstanceState) 

// Ensure the screen stays on during nav. window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) 

ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.navigation_view)) { v, insets ->   val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())   v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)   insets } 

private fun showToast(errorMessage: String) {    Toast.makeText(this@MainActivity, errorMessage, Toast.LENGTH_LONG).show() } 

/** Starts the Navigation API, capturing a reference when ready. */ @SuppressLint("MissingPermission") private fun initializeNavigationApi() {    NavigationApi.getNavigator(        this,        object : NavigatorListener {            override fun onNavigatorReady(navigator: Navigator) {                // store a reference to the Navigator object                mNavigator = navigator                // code to start guidance will go here            }             override fun onError(@NavigationApi.ErrorCode errorCode: Int) {                when (errorCode) {                    NavigationApi.ErrorCode.NOT_AUTHORIZED -> {                        // Note: If this message is displayed, you may need to check that                        // your API_KEY is specified correctly in AndroidManifest.xml                        // and is been enabled to access the Navigation API                        showToast(                            "Error loading Navigation API: Your API key is " +                                    "invalid or not authorized to use Navigation."                        )                    }                    NavigationApi.ErrorCode.TERMS_NOT_ACCEPTED -> {                        showToast(                            "Error loading Navigation API: User did not " +                                    "accept the Navigation Terms of Use."                        )                    }                    else -> showToast("Error loading Navigation API: $errorCode")                }            }        },    )  } 

private fun onLocationPermissionGranted() {    initializeNavigationApi() } 

private var arrivalListener: Navigator.ArrivalListener? = null private var routeChangedListener: Navigator.RouteChangedListener? = null 

/** * Registers a number of example event listeners that show an on screen message when certain * navigation events occur (e.g. the driver's route changes or the destination is reached). */ private fun registerNavigationListeners() {    withNavigatorAsync {        arrivalListener =            Navigator.ArrivalListener { // Show an onscreen message                showToast("User has arrived at the destination!")                mNavigator?.clearDestinations()            }        mNavigator?.addArrivalListener(arrivalListener)         routeChangedListener =            Navigator.RouteChangedListener { // Show an onscreen message when the route changes                showToast("onRouteChanged: the driver's route changed")            }        mNavigator?.addRouteChangedListener(routeChangedListener)    } } 

override fun onNavigatorReady(navigator: Navigator) {    // store a reference to the Navigator object    mNavigator = navigator     //listen for events en route    registerNavigationListeners()   } 

// Disables the guidance notifications and shuts down the app and background service // when the user dismisses/swipes away the app from Android's recent tasks. navigator.setTaskRemovedBehavior(Navigator.TaskRemovedBehavior.QUIT_SERVICE) 

navView.getMapAsync {    googleMap  ->    googleMap.followMyLocation(GoogleMap.CameraPerspective.TILTED) } 

override fun onSaveInstanceState(savedInstanceState: Bundle) {    super.onSaveInstanceState(savedInstanceState)     navView.onSaveInstanceState(savedInstanceState) }  override fun onTrimMemory(level: Int) {    super.onTrimMemory(level)    navView.onTrimMemory(level) }  override fun onStart() {    super.onStart()    navView.onStart() }  override fun onResume() {    super.onResume()    navView.onResume() }  override fun onPause() {    navView.onPause()    super.onPause() }  override fun onConfigurationChanged(configuration: Configuration) {    super.onConfigurationChanged(configuration)    navView.onConfigurationChanged(configuration) }  override fun onStop() {    navView.onStop()    super.onStop() }  override fun onDestroy() {    navView.onDestroy()    withNavigatorAsync {        // Unregister event listeners to avoid memory leaks.        if (arrivalListener != null) {            navigator.removeArrivalListener(arrivalListener)        }        if (routeChangedListener != null) {            navigator.removeRouteChangedListener(routeChangedListener)        }         navigator.simulator?.unsetUserLocation()        navigator.cleanup()    }    super.onDestroy() } 

/** * Requests directions from the user's current location to a specific place (provided by the * Place ID). */ private fun navigateToPlace(placeId: String) {  } 

val waypoint: Waypoint? = // Set a destination by using a Place ID (the recommended method) try {    Waypoint.builder().setPlaceIdString(placeId).build() } catch (e: Waypoint.UnsupportedPlaceIdException) {    showToast("Place ID was unsupported.")    return } 

val pendingRoute = mNavigator?.setDestination(waypoint)  // Set an action to perform when a route is determined to the destination pendingRoute?.setOnResultListener { code ->    when (code) {        RouteStatus.OK -> {            // Code to start guidance will go here        }         RouteStatus.ROUTE_CANCELED -> showToast("Route guidance canceled.")        RouteStatus.NO_ROUTE_FOUND,        RouteStatus.NETWORK_ERROR ->            // TODO: Add logic to handle when a route could not be determined            showToast("Error starting guidance: $code")         else -> showToast("Error starting guidance: $code")    } } 

// Hide the toolbar to maximize the navigation UI supportActionBar?.hide()  // Enable voice audio guidance (through the device speaker) mNavigator?.setAudioGuidance(Navigator.AudioGuidance.VOICE_ALERTS_AND_GUIDANCE)   // Simulate vehicle progress along the route (for demo/debug builds) if (BuildConfig.DEBUG) {    mNavigator?.simulator?.simulateLocationsAlongExistingRoute(        SimulationOptions().speedMultiplier(5f)    ) } 

companion object{    const val TRAFALGAR_SQUARE ="ChIJH-tBOc4EdkgRJ8aJ8P1CUxo" //London, UK    val startLocation = LatLng(51.345678, -0.1234456) } 

// Disables the guidance notifications and shuts down the app and background service // when the user dismisses/swipes away the app from Android's recent tasks. navigator.setTaskRemovedBehavior(Navigator.TaskRemovedBehavior.QUIT_SERVICE)  mNavigator = navigator  if (BuildConfig.DEBUG) {    mNavigator?.simulator?.setUserLocation(MainActivity.startLocation) } //listen for events en route registerNavigationListeners()  navView.getMapAsync {    googleMap  ->    googleMap.followMyLocation(GoogleMap.CameraPerspective.TILTED) }  //navigate to a destination navigateToPlace(MainActivity.TRAFALGAR_SQUARE) 

mNavigator?.simulator?.setUserLocation(startLocation)