應用程式可以監聽使用者沿著路線導航時發生的事件。
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請使用下列介面監聽導覽事件:
查看程式碼
顯示/隱藏導覽活動的 Java 程式碼。
package com.example.navsdkmultidestination;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import com.google.android.gms.maps.GoogleMap.CameraPerspective;
import com.google.android.libraries.navigation.ArrivalEvent;
import com.google.android.libraries.navigation.ListenableResultFuture;
import com.google.android.libraries.navigation.NavigationApi;
import com.google.android.libraries.navigation.Navigator;
import com.google.android.libraries.navigation.RoadSnappedLocationProvider;
import com.google.android.libraries.navigation.SimulationOptions;
import com.google.android.libraries.navigation.SupportNavigationFragment;
import com.google.android.libraries.navigation.TimeAndDistance;
import com.google.android.libraries.navigation.Waypoint;
import java.util.ArrayList;
import java.util.List;
/**
* An activity that displays a map and a navigation UI, guiding the user from their current location
* to multiple destinations, also known as waypoints.
*/
public class NavigationActivityMultiDestination extends AppCompatActivity {
private static final String TAG = NavigationActivityMultiDestination.class.getSimpleName();
private static final String DISPLAY_BOTH = "both";
private static final String DISPLAY_TOAST = "toast";
private static final String DISPLAY_LOG = "log";
private Navigator mNavigator;
private RoadSnappedLocationProvider mRoadSnappedLocationProvider;
private SupportNavigationFragment mNavFragment;
private final List<Waypoint> mWaypoints = new ArrayList<>();
private Navigator.ArrivalListener mArrivalListener;
private Navigator.RouteChangedListener mRouteChangedListener;
private Navigator.RemainingTimeOrDistanceChangedListener mRemainingTimeOrDistanceChangedListener;
private RoadSnappedLocationProvider.LocationListener mLocationListener;
private Bundle mSavedInstanceState;
private static final String KEY_JOURNEY_IN_PROGRESS = "journey_in_progress";
private boolean mJourneyInProgress = false;
// Set fields for requesting location permission.
private static final int PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION = 1;
private boolean mLocationPermissionGranted;
/**
* Sets up the navigator when the activity is created.
*
* @param savedInstanceState The activity state bundle.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Save the navigator state, used to determine whether a journey is in progress.
mSavedInstanceState = savedInstanceState;
if (mSavedInstanceState != null && mSavedInstanceState.containsKey(KEY_JOURNEY_IN_PROGRESS)) {
mJourneyInProgress = (mSavedInstanceState.getInt(KEY_JOURNEY_IN_PROGRESS) != 0);
}
setContentView(R.layout.activity_main);
// Initialize the Navigation SDK.
initializeNavigationSdk();
}
/** Releases navigation listeners when the activity is destroyed. */
@Override
protected void onDestroy() {
super.onDestroy();
if ((mJourneyInProgress) && (this.isFinishing())) {
mNavigator.removeArrivalListener(mArrivalListener);
mNavigator.removeRouteChangedListener(mRouteChangedListener);
mNavigator.removeRemainingTimeOrDistanceChangedListener(
mRemainingTimeOrDistanceChangedListener);
if (mRoadSnappedLocationProvider != null) {
mRoadSnappedLocationProvider.removeLocationListener(mLocationListener);
}
displayMessage("OnDestroy: Released navigation listeners.", DISPLAY_LOG);
}
}
/** Saves the state of the app when the activity is paused. */
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (mJourneyInProgress) {
outState.putInt(KEY_JOURNEY_IN_PROGRESS, 1);
} else {
outState.putInt(KEY_JOURNEY_IN_PROGRESS, 0);
}
}
/**
* Starts the Navigation SDK and sets the camera to follow the device's location. Calls the
* navigateToPlaces() method when the navigator is ready.
*/
private void initializeNavigationSdk() {
/*
* Request location permission, so that we can get the location of the
* device. The result of the permission request is handled by a callback,
* onRequestPermissionsResult.
*/
if (ContextCompat.checkSelfPermission(
this.getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
mLocationPermissionGranted = true;
} else {
ActivityCompat.requestPermissions(
this,
new String[] {android.Manifest.permission.ACCESS_FINE_LOCATION},
PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);
}
if (!mLocationPermissionGranted) {
displayMessage(
"Error loading Navigation SDK: " + "The user has not granted location permission.",
DISPLAY_BOTH);
return;
}
// Get a navigator.
NavigationApi.getNavigator(
this,
new NavigationApi.NavigatorListener() {
/** Sets up the navigation UI when the navigator is ready for use. */
@Override
public void onNavigatorReady(Navigator navigator) {
displayMessage("Navigator ready.", DISPLAY_BOTH);
mNavigator = navigator;
mNavFragment =
(SupportNavigationFragment)
getSupportFragmentManager().findFragmentById(R.id.navigation_fragment);
// Set the camera to follow the device location with 'TILTED' driving view.
mNavFragment.getMapAsync(
googleMap -> googleMap.followMyLocation(CameraPerspective.TILTED));
// Navigate to the specified places.
navigateToPlaces();
}
/**
* Handles errors from the Navigation SDK.
*
* @param errorCode The error code returned by the navigator.
*/
@Override
public void onError(@NavigationApi.ErrorCode int errorCode) {
switch (errorCode) {
case NavigationApi.ErrorCode.NOT_AUTHORIZED:
displayMessage(
"Error loading Navigation SDK: Your API key is "
+ "invalid or not authorized to use the Navigation SDK.",
DISPLAY_BOTH);
break;
case NavigationApi.ErrorCode.TERMS_NOT_ACCEPTED:
displayMessage(
"Error loading Navigation SDK: User did not accept "
+ "the Navigation Terms of Use.",
DISPLAY_BOTH);
break;
case NavigationApi.ErrorCode.NETWORK_ERROR:
displayMessage("Error loading Navigation SDK: Network error.", DISPLAY_BOTH);
break;
case NavigationApi.ErrorCode.LOCATION_PERMISSION_MISSING:
displayMessage(
"Error loading Navigation SDK: Location permission " + "is missing.",
DISPLAY_BOTH);
break;
default:
displayMessage("Error loading Navigation SDK: " + errorCode, DISPLAY_BOTH);
}
}
});
}
/** Requests directions from the user's current location to a list of waypoints. */
private void navigateToPlaces() {
// Set up a waypoint for each place that we want to go to.
createWaypoint("ChIJq6qq6jauEmsRJAf7FjrKnXI", "Sydney Star");
createWaypoint("ChIJ3S-JXmauEmsRUcIaWtf4MzE", "Sydney Opera House");
createWaypoint("ChIJLwgLFGmuEmsRzpDhHQuyyoU", "Sydney Conservatorium of Music");
// If this journey is already in progress, no need to restart navigation.
// This can happen when the user rotates the device, or sends the app to the background.
if (mSavedInstanceState != null
&& mSavedInstanceState.containsKey(KEY_JOURNEY_IN_PROGRESS)
&& mSavedInstanceState.getInt(KEY_JOURNEY_IN_PROGRESS) == 1) {
return;
}
// Create a future to await the result of the asynchronous navigator task.
ListenableResultFuture<Navigator.RouteStatus> pendingRoute =
mNavigator.setDestinations(mWaypoints);
// Define the action to perform when the SDK has determined the route.
pendingRoute.setOnResultListener(
new ListenableResultFuture.OnResultListener<Navigator.RouteStatus>() {
@Override
public void onResult(Navigator.RouteStatus code) {
switch (code) {
case OK:
mJourneyInProgress = true;
// Hide the toolbar to maximize the navigation UI.
if (getActionBar() != null) {
getActionBar().hide();
}
// Register some listeners for navigation events.
registerNavigationListeners();
// Display the time and distance to each waypoint.
displayTimesAndDistances();
// 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
.getSimulator()
.simulateLocationsAlongExistingRoute(
new SimulationOptions().speedMultiplier(5));
}
// Start turn-by-turn guidance along the current route.
mNavigator.startGuidance();
break;
// Handle error conditions returned by the navigator.
case NO_ROUTE_FOUND:
displayMessage("Error starting navigation: No route found.", DISPLAY_BOTH);
break;
case NETWORK_ERROR:
displayMessage("Error starting navigation: Network error.", DISPLAY_BOTH);
break;
case ROUTE_CANCELED:
displayMessage("Error starting navigation: Route canceled.", DISPLAY_BOTH);
break;
default:
displayMessage("Error starting navigation: " + String.valueOf(code), DISPLAY_BOTH);
}
}
});
}
/**
* Creates a waypoint from a given place ID and title.
*
* @param placeId The ID of the place to be converted to a waypoint.
* @param title A descriptive title for the waypoint.
*/
private void createWaypoint(String placeId, String title) {
try {
mWaypoints.add(Waypoint.builder().setPlaceIdString(placeId).setTitle(title).build());
} catch (Waypoint.UnsupportedPlaceIdException e) {
displayMessage(
"Error starting navigation: Place ID is not supported: " + placeId, DISPLAY_BOTH);
}
}
/** Displays the calculated travel time and distance to each waypoint. */
private void displayTimesAndDistances() {
List<TimeAndDistance> timesAndDistances = mNavigator.getTimeAndDistanceList();
int leg = 1;
String message = "You're on your way!";
for (TimeAndDistance timeAndDistance : timesAndDistances) {
message =
message
+ "\nRoute leg: "
+ leg++
+ ": Travel time (seconds): "
+ timeAndDistance.getSeconds()
+ ". Distance (meters): "
+ timeAndDistance.getMeters();
}
displayMessage(message, DISPLAY_BOTH);
}
/**
* Registers some event listeners to show a message and take other necessary steps when specific
* navigation events occur.
*/
private void registerNavigationListeners() {
mArrivalListener =
new Navigator.ArrivalListener() {
@Override
public void onArrival(ArrivalEvent arrivalEvent) {
displayMessage(
"onArrival: You've arrived at a waypoint: "
+ mNavigator.getCurrentRouteSegment().getDestinationWaypoint().getTitle(),
DISPLAY_BOTH);
// Start turn-by-turn guidance for the next leg of the route.
if (arrivalEvent.isFinalDestination()) {
displayMessage("onArrival: You've arrived at the final destination.", DISPLAY_BOTH);
} else {
mNavigator.continueToNextDestination();
mNavigator.startGuidance();
}
}
};
// Listens for arrival at a waypoint.
mNavigator.addArrivalListener(mArrivalListener);
mRouteChangedListener =
new Navigator.RouteChangedListener() {
@Override
public void onRouteChanged() {
displayMessage(
"onRouteChanged: The driver's route has changed. Current waypoint: "
+ mNavigator.getCurrentRouteSegment().getDestinationWaypoint().getTitle(),
DISPLAY_LOG);
}
};
// Listens for changes in the route.
mNavigator.addRouteChangedListener(mRouteChangedListener);
// Listens for road-snapped location updates.
mRoadSnappedLocationProvider = NavigationApi.getRoadSnappedLocationProvider(getApplication());
mLocationListener =
new RoadSnappedLocationProvider.LocationListener() {
@Override
public void onLocationChanged(Location location) {
displayMessage(
"onLocationUpdated: Navigation engine has provided a new"
+ " road-snapped location: "
+ location.toString(),
DISPLAY_LOG);
}
@Override
public void onRawLocationUpdate(Location location) {
displayMessage(
"onLocationUpdated: Navigation engine has provided a new"
+ " raw location: "
+ location.toString(),
DISPLAY_LOG);
}
};
if (mRoadSnappedLocationProvider != null) {
mRoadSnappedLocationProvider.addLocationListener(mLocationListener);
} else {
displayMessage("ERROR: Failed to get a location provider", DISPLAY_LOG);
}
mRemainingTimeOrDistanceChangedListener =
new Navigator.RemainingTimeOrDistanceChangedListener() {
@Override
public void onRemainingTimeOrDistanceChanged() {
displayMessage(
"onRemainingTimeOrDistanceChanged: Time or distance estimate" + " has changed.",
DISPLAY_LOG);
}
};
// Listens for changes in time or distance.
mNavigator.addRemainingTimeOrDistanceChangedListener(
60, 100, mRemainingTimeOrDistanceChangedListener);
}
/** Handles the result of the request for location permissions. */
@Override
public void onRequestPermissionsResult(
int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
mLocationPermissionGranted = false;
switch (requestCode) {
case PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION:
{
// If request is canceled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
mLocationPermissionGranted = true;
}
}
}
}
/**
* Shows a message on screen and in the log. Used when something goes wrong.
*
* @param errorMessage The message to display.
*/
private void displayMessage(String errorMessage, String displayMedium) {
if (displayMedium.equals(DISPLAY_BOTH) || displayMedium.equals(DISPLAY_TOAST)) {
Toast.makeText(this, errorMessage, Toast.LENGTH_LONG).show();
}
if (displayMedium.equals(DISPLAY_BOTH) || displayMedium.equals(DISPLAY_LOG)) {
Log.d(TAG, errorMessage);
}
}
}
偵測抵達目的地
這裡的「目的地」是指最終目的地或路線點。如要偵測抵達目的地,請呼叫 Navigator.addArrivalListener()
,系統會在裝置抵達目的地時註冊回呼。
抵達目的地後,Android 版 Navigation SDK 會觸發 onArrival()
回呼,並停止即時路況導航。您必須明確呼叫 Navigator.continueToNextDestination()
才能前往下一個路標,並呼叫 Navigator.startGuidance()
才能繼續行車路線導航。
當您呼叫 continueToNextDestination()
時,導覽器會捨棄與上一個目的地相關的所有資訊。如要分析先前路線區段的資訊,您必須先從導航器擷取資訊,再呼叫 continueToNextDestination()
。
為避免記憶體流失,不再需要事件監聽器時,必須呼叫 removeArrivalListener(listener)
。
mNavigator.addArrivalListener(new Navigator.ArrivalListener() {
@Override
public void onArrival(ArrivalEvent arrivalEvent) {
displayMessage("onArrival: You've arrived at a waypoint: "
+ mNavigator.getCurrentRouteSegment().getDestinationWaypoint().getTitle(),
DISPLAY_BOTH);
// Start turn-by-turn guidance for the next leg of the route.
if (arrivalEvent.isFinalDestination()) {
displayMessage("onArrival: You've arrived at the final destination.",
DISPLAY_BOTH);
} else {
mNavigator.continueToNextDestination();
mNavigator.startGuidance();
}
}
});
接收位置更新資訊
從 NavigationApi
取得 RoadSnappedLocationProvider
,然後呼叫 RoadSnappedLocationProvider.addLocationListener()
,在裝置位置或標頭變更時註冊回呼。請注意,這個位置會對齊道路,因此可能與 Google Play 服務位置 API 中的整合式位置預測提供工具所傳回的位置不同。
Navigation SDK 會盡可能提供位置更新通知。有位置更新可用時,Navigation SDK 會觸發 onLocationChanged()
回呼。
路線定位更新與導航無關,即使導航停止後也能繼續。訂閱位置更新後,如果您在背景執行位置資訊更新,可能會導致電池耗電、記憶體流失,或不小心收集裝置位置資料。不再需要事件監聽器時,請呼叫 RoadSnappedLocationProvider.removeLocationListener
。
mRoadSnappedLocationProvider =
NavigationApi.getRoadSnappedLocationProvider(getApplication());
if (mRoadSnappedLocationProvider != null) {
mRoadSnappedLocationProvider.addLocationListener(
new RoadSnappedLocationProvider.LocationListener() {
@Override
public void onLocationChanged(Location location) {
displayMessage("onLocationUpdated: Navigation engine has provided a new"
+ " road-snapped location: "
+ location.toString(),
DISPLAY_LOG);
}
});
} else {
displayMessage("ERROR: Failed to get a location provider", DISPLAY_LOG);
}
接收最新的時間和距離資訊
呼叫 Navigator.addRemainingTimeOrDistanceChangedListener()
時,如果剩餘時間 (秒) 或距離 (公尺) 變更超過指定的閾值,系統就會註冊回呼。
時間或距離變更超過指定值時,Navigation SDK 會觸發 onRemainingTimeOrDistanceChanged()
回呼。
如要查看剩餘時間和距離,請呼叫 Navigator.getTimeAndDistanceList()
。請注意,清單中的時間和距離是累加的:顯示從目前位置到每個路標的時間和距離,而非從一個路標到另一個路標的時間和距離。TimeAndDistance
物件現在也會傳回 delaySeverity
。列舉為粗體、中間值、淺色或未知。這與地圖 UI 中顯示的顏色對應 (粗體 = 紅色,中型 = 黃色,淺綠色 = 綠色)。如果您需要自行建立 ETA 頁尾,這項功能就很實用。
為避免記憶體流失,您必須在不再需要事件監聽器時呼叫 Navigator.removeRemainingTimeOrDistanceChangedListener(listener)
。
當剩餘時間變更超過 60 秒,或剩餘距離變更超過 100 公尺時,下列範例會要求回呼。
mNavigator.addRemainingTimeOrDistanceChangedListener(60, 100,
new Navigator.RemainingTimeOrDistanceChangedListener() {
@Override
public void onRemainingTimeOrDistanceChanged() {
displayMessage("onRemainingTimeOrDistanceChanged: Time or distance estimate"
+ " has changed.",
DISPLAY_LOG);
}
});
您可以使用 setEtaCardEnabled()
方法,並傳遞值為 TRUE
的參數,透過內建顯示器顯示剩餘時間和距離資訊。如要隱藏時間和距離顯示資訊,請將這個值設為 FALSE
。
您也可以使用 getTimeAndDistanceList()
方法,公開多個路線控點的預估抵達時間。
接收路線更新
呼叫 Navigator.addRouteChangedListener()
以在路徑變更時註冊回呼。
當路徑變更時,Navigation SDK 會觸發 onRouteChanged()
回呼。您可以呼叫 Navigator.getRouteSegments
和 Navigator.getCurrentRouteSegment()
來尋找新路線。
為避免記憶體流失,您必須在不再需要事件監聽器時呼叫 removeRouteChangedListener(listener)
。
mNavigator.addRouteChangedListener(new Navigator.RouteChangedListener() {
@Override
public void onRouteChanged() {
displayMessage("onRouteChanged: The driver's route has changed. Current waypoint: "
+ mNavigator.getCurrentRouteSegment().getDestinationWaypoint().getTitle(),
DISPLAY_LOG);
}
});
在夜間模式變更時偵測
呼叫 NavigationView.addOnNightModeChangedListener
或 SupportNavigationFragment.addOnNightModeChangedListener
,註冊在夜間模式變更時註冊回呼。
以下範例說明如何在導覽片段上監聽夜間模式變更。
mNavFragment.addOnNightModeChangedListener(new NavigationView.OnNightModeChangedListener() {
@Override
public void onNightModeChanged(NightModeChangedEvent nightModeChangedEvent) {
displayMessage("Night mode is active: " + nightModeChangedEvent.inNightMode(),
DISPLAY_LOG);
}
});
你也可以透過程式輔助方式設定夜間模式。詳情請參閱「設定夜間模式」。