要在Google地图中的两个Lat Lng边界之间缩放，请执行以下操作：
首先，在pubspec.yaml中的库下面导入，否则对于较旧的版本，您可能无法使用Google Map Controller看到“
getVisibleRegion（）”方法。
google_maps_flutter：^ 0.5.12
import 'dart:async';import 'package:flutter/material.dart';import 'package:google_maps_flutter/google_maps_flutter.dart';void main() => runApp(MyApp());class MyApp extends StatefulWidget { @override _MyAppState createState() => _MyAppState();}class _MyAppState extends State<MyApp> { Completer<GoogleMapController> _controller = Completer(); GoogleMapController mapController; LatLng _lastMapPosition = _center; static const LatLng _center = const LatLng(45.521563, -122.677433); final Set<Marker> _markers = {}; void _onMapCreated(GoogleMapController controller) { mapController = controller; _controller.complete(controller); LatLng latLng_1 = LatLng(40.416775, -3.70379); LatLng latLng_2 = LatLng(41.385064, 2.173403); LatLngBounds bound = LatLngBounds(southwest: latLng_1, northeast: latLng_2); setState(() { _markers.clear(); addMarker(latLng_1, "Madrid", "5 Star Rating"); addMarker(latLng_2, "Barcelona", "7 Star Rating"); }); CameraUpdate u2 = CameraUpdate.newLatLngBounds(bound, 50); this.mapController.animateCamera(u2).then((void v){ check(u2,this.mapController); }); } void addMarker(LatLng mLatLng, String mTitle, String mDescription){ _markers.add(Marker( // This marker id can be anything that uniquely identifies each marker. markerId: MarkerId((mTitle + "_" + _markers.length.toString()).toString()), position: mLatLng, infoWindow: InfoWindow( title: mTitle, snippet: mDescription, ), icon: BitmapDescriptor.defaultMarker, )); } void check(CameraUpdate u, GoogleMapController c) async { c.animateCamera(u); mapController.animateCamera(u); LatLngBounds l1=await c.getVisibleRegion(); LatLngBounds l2=await c.getVisibleRegion(); print(l1.toString()); print(l2.toString()); if(l1.southwest.latitude==-90 ||l2.southwest.latitude==-90) check(u, c); } void _onCameraMove(CameraPosition position) { _lastMapPosition = position.target; } @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar( title: Text('Maps Sample App'), backgroundColor: Colors.green[700], ), body: GoogleMap( markers: _markers, onMapCreated: _onMapCreated, initialCameraPosition: CameraPosition( target: _center, zoom: 11.0, ), onCameraMove: _onCameraMove, ), ), ); }}
