FlutterMap LateInitializationError State Management-CodePudding

I'm trying to make a Flutter app, using Riverpod for state management and FlutterMaps. I have set up notifiers for pages, and am also using a (State)NotifierProvider for the map page. I am building a search function, which goes to a search page which displays a list with search results. When one of these results (in a list) is clicked, I update the notifier of the map page. However, here comes the tricky part: I want to update the map according to the LatLng of the search result (center it).

My implementation of the Notifier contains: late MapController? _mapController;

My map page is loaded in and gets the mapController from the Notifier: mapController: notifier.getMapController()

Using Riverpod state management, this all should work, however I get the following Error:

LateError (LateInitializationError: Field '_state@1225051772' has already been initialized.)

This Error is within the MapController itself (which is part of the FlutterMaps package), so I do not want to touch that. Does anyone have any idea how to tackle this?

CodePudding user response：

you should remove the late keyword or you should intialise it in the initState method.

CodePudding user response：

lateerror is caused by nulling a variable that will fill before the application starts.

late MapController? _mapController;

this definition is wrong. Here, you are saying that this value will fill in soon. You also say that this value can be null.

late MapController _mapController;

if you do so this variable should not be null at runtime. if it is null you will get a lateerror error.

MapController? _mapController;

if you do it this way. This means that the value can be null. You should check when using. like this

void sameFunction(){
 if(_mapController!=null){
  ... your code
 // here make sure this variable is not null. For this reason ! i put this
  MapController anotherController=_mapController!;
}
}

 void sameFunction(){
  // Your code will not throw an error if this variable is null. Because specify that 
  //it can be null
     mapController?.moveTo(...)
    }

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