Aaron009

import 'package:flutter/material.dart';
import 'dart:math' as math;

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',

Aaron009

//This is probably my own problem, but I don't know what caused it , how to solve it.

//example:
//Clicking on the blue circle button, clicking on it will add a tabitem, but now clicking it will not respond.

import 'dart:math';
import 'package:flutter/material.dart';

void main() {
  runApp(

Aaron009

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(),