Can you help me solving this error in flutter , which says 'Error: Can't access 'this' in a field initializer.'?

Here is my code:

The error is at line :

onTap: () => _showActionSheet(this.context),

I don’t know whats the problem is with this line as I’m a beginner in the flutter. So please help me solving this error.

>Solution :

Firstly, you may use method instead of variable for this.

List<Marker> _list()=>[...]

You can do lazy initialization, but sometimes you may face some issue update context.

late List<Marker> _list = [...]