Flutter：未处理的异常：用户拒绝访问设备位置的权限

Question

我试图在 flutter 中获取用户当前位置，但它显示地图，但不指向我当前的位置。我已在 AndriodManifest 文件中添加了所有必需的权限。

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这是快照

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这是日志

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I/Google Maps Android API(24140): Google Play services package version: 201817022\nE/GoogleMapController(24140): Cannot enable MyLocation layer as location permissions are not granted\nD/HostConnection(24140): HostConnection::get() New Host Connection established 0xefab0ec0, tid 25110\nE/flutter (24140): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: User denied permissions to access the device\'s location.\nE/flutter (24140): #0      MethodChannelGeolocator._handlePlatformException\npackage:geolocator_platform_interface/\xe2\x80\xa6/implementations/method_channel_geolocator.dart:242\nE/flutter (24140): #1      MethodChannelGeolocator.getCurrentPosition\npackage:geolocator_platform_interface/\xe2\x80\xa6/implementations/method_channel_geolocator.dart:124\nE/flutter (24140): <asynchronous suspension>\nE/flutter (24140): #2      _locationState.locatepostion\npackage:map_app/abc.dart:26\nE/flutter (24140): <asynchronous suspension>\nW/System  (24140): A resource failed to call release.\n

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代码

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  Completer<GoogleMapController> _controllerGoogleMap=Completer();\n  late GoogleMapController newGoogleMapController;\n  double mapbottompadding=0;\n\n  GlobalKey<ScaffoldState> scaffoldkey=new GlobalKey<ScaffoldState>();\n  late Position currentpositon;\n  var geolocator=Geolocator();\n\n  void locatepostion() async{\n    Position position=await Geolocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.high);\n    currentpositon=position;  // this is line 26, it is point before await\n\n    LatLng latLngPosition=LatLng(position.latitude,position.longitude);\n\n    CameraPosition cameraPosition=new CameraPosition(target: latLngPosition,zoom: 14);\n    newGoogleMapController.animateCamera(CameraUpdate.newCameraPosition(cameraPosition));\n  }\n\n  static final CameraPosition googlepostion=CameraPosition(target: LatLng(37.4249,-122.0657));\n\n  @override\n  Widget build(BuildContext context) {\n    return Scaffold(\n      body: Stack(children: [\n        GoogleMap(\n          padding: EdgeInsets.only(bottom: mapbottompadding),\n          mapType: MapType.normal,\n          myLocationButtonEnabled: true,\n          myLocationEnabled: true,\n          zoomControlsEnabled: true,\n          zoomGesturesEnabled: true,\n           initialCameraPosition: googlepostion,\n          onMapCreated: (GoogleMapController controller){\n              _controllerGoogleMap.complete(controller);\n              newGoogleMapController=controller;\n              setState(() {\n                mapbottompadding=300.0;\n              });         \n              locatepostion();\n         \n\n

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这是我的输出

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- - - -更新

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它在 android 手机上完美运行，但在模拟器上无法运行。

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Answer 1

 LocationPermission permission;
   permission = await Geolocator.requestPermission();

首先使用此请求权限。

Answer 2

class GeolocatorService {
  Future<Position?> determinePosition() async {
    LocationPermission permission;
    permission = await Geolocator.checkPermission();
    if (permission == LocationPermission.denied) {
      permission = await Geolocator.requestPermission();
      if (permission == LocationPermission.deniedForever) {
        return Future.error('Location Not Available');
      }
    } else {
      throw Exception('Error');
    }
    return await Geolocator.getCurrentPosition();
  }
}

Answer 3

这是地理定位器中出现的常见问题，尤其是。当您未授予设备权限时。默认情况下它是禁用的，因此您必须在locatePosition()调用时请求它。请记住，地理定位器包包装在google_maps_flutter下。因此，要解决位置问题，请确保执行以下操作

class _MapScreenState extends State<MapScreen> {
void locatePosition() async {
    bool isLocationServiceEnabled = await Geolocator.isLocationServiceEnabled();
    
    await Geolocator.checkPermission();
    await Geolocator.requestPermission();
    
    Position position = await Geolocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
    
    currentPosition = position;
    LatLng latLngPosition = LatLng(position.latitude, position.longitude);
        
    // Ask permission from device
    Future<void> requestPermission() async {
    await Permission.location.request();
    }
}