Flutter _AssertionError 'initialValue == null || controller == null': is not true. Error

I have a code like this: TextEditingController adSoyadTextBox = TextEditingController(text: "Loading.."); // … TextFormField( controller: adSoyadTextBox, initialValue: ad, decoration: InputDecoration( hintStyle: TextStyle(color: Colors.grey), enabledBorder: UnderlineInputBorder( borderSide: BorderSide(color: Colors.grey), ), focusedBorder: UnderlineInputBorder( borderSide: BorderSide(color: Colors.grey), ), ), ), My code throws an error like this: _AssertionError (‘package:flutter/src/material/text_form_field.dart’: Failed assertion: line 155 pos 15: ‘initialValue == null… Read More Flutter _AssertionError 'initialValue == null || controller == null': is not true. Error

How can I solve FileSystemException: Cannot retrieve length of file, path ='…'

E/flutter ( 8324): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: FileSystemException: Cannot retrieve length of file, path = ‘File: ‘/data/user/0/com.example.upload/cache/file_picker/download (1).jpeg” (OS Error: No such file or directory, errno = 2) E/flutter ( 8324): #0 _File.length.<anonymous closure> (dart:io/file_impl.dart:366:9) E/flutter ( 8324): #1 _rootRunUnary (dart:async/zone.dart:1434:47) E/flutter ( 8324): #2 _CustomZone.runUnary (dart:async/zone.dart:1335:19) E/flutter ( 8324): <asynchronous suspension> E/flutter ( 8324): #3… Read More How can I solve FileSystemException: Cannot retrieve length of file, path ='…'

how to place logo before the text flutter app bar

I’m new to flutter creating a video screen flutter. this is the app bar and tab bar I have created for my app. I want to place my logo (middle image) before the "lalalive" word. how can I do that. appreciate your help on this….. ……………………….. ………………….. …………………………………………. import ‘package:flutter/material.dart’; import ‘package:lala_live/screens/post_template.dart’; class VideoScreen extends… Read More how to place logo before the text flutter app bar

RangeError (index): Invalid value: Not in inclusive range 0..2: 3 i cant fix

i have a problem this my list class _FitnessAppState extends State<FitnessApp> { String img_Header = "https://images.unsplash.com/photo-1517836357463-d25dfeac3438?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=870&q=80&quot;; List trainingImage = [ "https://images.unsplash.com/photo-1534258936925-c58bed479fcb?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1631&q=80&quot;, "https://images.unsplash.com/photo-1575052814086-f385e2e2ad1b?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1170&q=80&quot;, "https://media.istockphoto.com/photos/picture-of-people-running-on-treadmill-in-gym-picture-id879180126?k=20&m=879180126&s=612×612&w=0&h=WZ1Iqcqv5_rNTNslUscoMg9qAUoNiDG8kWBfVnpPapQ=&quot;, ]; >Solution : your variables are: String img_Header = "https://images.unsplash.com/photo-1517836357463-d25dfeac3438?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=870&q=80&quot;; List trainingImage = [ "https://images.unsplash.com/photo-1534258936925-c58bed479fcb?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1631&q=80&quot;, "https://images.unsplash.com/photo-1575052814086-f385e2e2ad1b?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1170&q=80&quot;, "https://media.istockphoto.com/photos/picture-of-people-running-on-treadmill-in-gym-picture-id879180126?k=20&m=879180126&s=612×612&w=0&h=WZ1Iqcqv5_rNTNslUscoMg9qAUoNiDG8kWBfVnpPapQ=&quot;, ]; the error of RangeError is happened in trainingImage variable as it is a List… Read More RangeError (index): Invalid value: Not in inclusive range 0..2: 3 i cant fix