替换google map

+import 'dart:async';
+import 'dart:math';
+
 import 'package:location/location.dart';
 import 'package:location/location.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/material.dart';
 import 'package:Parlando/widgets/my_button.dart';
 import 'package:Parlando/widgets/my_button.dart';
@@ -22,10 +25,14 @@ class AddressSelectPageState extends State<AddressSelectPage> {
   LatLng _center = const LatLng(45.521563, -122.677433);
   LatLng _center = const LatLng(45.521563, -122.677433);
   late GoogleMapController mapController;
   late GoogleMapController mapController;
   bool isLoading = false;
   bool isLoading = false;
+  int _markerIdCounter = 1;
+  Map<MarkerId, Marker> markers = <MarkerId, Marker>{};
+  late StreamSubscription _locationSubscription;
 
 
   @override
   @override
   void dispose() {
   void dispose() {
     _controller.dispose();
     _controller.dispose();
+    _locationSubscription.cancel();
     super.dispose();
     super.dispose();
   }
   }
 
 
@@ -40,7 +47,6 @@ class AddressSelectPageState extends State<AddressSelectPage> {
 
 
     bool serviceEnabled;
     bool serviceEnabled;
     PermissionStatus permissionGranted;
     PermissionStatus permissionGranted;
-
     serviceEnabled = await location.serviceEnabled();
     serviceEnabled = await location.serviceEnabled();
     if (!serviceEnabled) {
     if (!serviceEnabled) {
       serviceEnabled = await location.requestService();
       serviceEnabled = await location.requestService();
@@ -48,7 +54,6 @@ class AddressSelectPageState extends State<AddressSelectPage> {
         return;
         return;
       }
       }
     }
     }
-
     permissionGranted = await location.hasPermission();
     permissionGranted = await location.hasPermission();
     if (permissionGranted == PermissionStatus.denied) {
     if (permissionGranted == PermissionStatus.denied) {
       permissionGranted = await location.requestPermission();
       permissionGranted = await location.requestPermission();
@@ -57,9 +62,25 @@ class AddressSelectPageState extends State<AddressSelectPage> {
       }
       }
     }
     }
 
 
-    location.onLocationChanged.listen((LocationData currentLocation) {
-      // _center = LatLng(currentLocation.latitude!, currentLocation.longitude!);
-      setState(() {});
+    _locationSubscription =
+        location.onLocationChanged.listen((LocationData currentLocation) {
+      _center = LatLng(currentLocation.latitude!, currentLocation.longitude!);
+
+      final String markerIdVal = 'marker_id_$_markerIdCounter';
+      _markerIdCounter++;
+      final MarkerId markerId = MarkerId(markerIdVal);
+
+      final Marker marker = Marker(
+        markerId: markerId,
+        position: LatLng(currentLocation.latitude!, currentLocation.longitude!),
+      );
+
+      LatLng sydney =
+          LatLng(currentLocation.latitude!, currentLocation.longitude!);
+      mapController.moveCamera(CameraUpdate.newLatLng(sydney));
+      setState(() {
+        markers[markerId] = marker;
+      });
     });
     });
   }
   }
 
 
@@ -90,8 +111,9 @@ class AddressSelectPageState extends State<AddressSelectPage> {
                 onMapCreated: _onMapCreated,
                 onMapCreated: _onMapCreated,
                 initialCameraPosition: CameraPosition(
                 initialCameraPosition: CameraPosition(
                   target: _center,
                   target: _center,
-                  zoom: 11.0,
+                  zoom: 16.0,
                 ),
                 ),
+                markers: Set<Marker>.of(markers.values),
               ),
               ),
             ),
             ),
             Expanded(
             Expanded(
@@ -111,7 +133,7 @@ class AddressSelectPageState extends State<AddressSelectPage> {
                           },
                           },
                         );
                         );
                       },
                       },
-                    ),
+              ),
             ),
             ),
             MyButton(
             MyButton(
               onPressed: () {
               onPressed: () {