errore

════════ Exception caught by gesture ═══════════════════════════════════════════════════════════════
The following assertion was thrown while handling a gesture:
setState() called in constructor: AddProposalPage#decff(lifecycle state: created, no widget, not mounted)


This happens when you call setState() on a State object for a widget that hasn't been inserted into the widget tree yet. It is not necessary to call setState() in the constructor, since the state is already assumed to be dirty when it is initially created.

When the exception was thrown, this was the stack:
#0      State.setState.<anonymous closure> (package:flutter/src/widgets/framework.dart:1136:9)
#1      State.setState (package:flutter/src/widgets/framework.dart:1147:6)
#2      AddProposalPage.onTappedAddFeed (package:myairbnb_webapp/views/addproposalpage.dart:19:5)
#3      WelcomePage.build.<anonymous closure>.<anonymous closure> (package:myairbnb_webapp/views/welcomepage.dart:164:39)
#4      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:706:14)
...
Handler: "onTap"
Recognizer: TapGestureRecognizer#06693
  debugOwner: GestureDetector
  state: ready
  won arena
  finalPosition: Offset(101.5, 477.5)
  finalLocalPosition: Offset(101.5, 26.5)
  button: 1
  sent tap down
════════════════════════════════════════════════════════════════════════════════════════════════════