MDC-103 Flutter: Material Theming with Color, Shape, Elevation, and Type (Flutter)

[Zheng-Shuo]

Hi, i got an exception when i ran the demo code, i don't know how to fix it, please help me, thank you.

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        brightness: Brightness.light,
        leading: IconButton(
          icon: Icon(Icons.menu),
          onPressed: () {
            print('Menu button');
          },
        ),
        title: Text('SHRINE'),
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.search),
            onPressed: () {
              print('Search button');
            },
          ),
          IconButton(
            icon: Icon(Icons.tune),
            onPressed: () {
              print('Filter button');
            },
          ),
        ],
      ),
      body: AsymmetricView(products: getProducts(Category.all)),
    );
  }
}

I/flutter ( 4768): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 4768): The following _CompileTimeError was thrown building HomePage(dirty):
I/flutter ( 4768): 'file:*****/lib/home.dart': error: line 49 pos 38:
I/flutter ( 4768): lib/home.dart:49:38: Error: A value of type 'dart.core::List<#lib1::Product>' can't be assigned to a
I/flutter ( 4768): variable of type 'dart.core::List<#lib2::Product>'.
I/flutter ( 4768): Try changing the type of the left hand side, or casting the right hand side to
I/flutter ( 4768): 'dart.core::List<#lib2::Product>'.
I/flutter ( 4768): body: AsymmetricView(products: getProducts(Category.all)),
I/flutter ( 4768): ^
I/flutter ( 4768): body: AsymmetricView(products: getProducts(Category.all)),
I/flutter ( 4768): ^
I/flutter ( 4768):
I/flutter ( 4768): When the exception was thrown, this was the stack:
I/flutter ( 4768): #0 StatelessElement.build (package:flutter/src/widgets/framework.dart:3695:28)
I/flutter ( 4768): #1 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3642:15)
I/flutter ( 4768): #2 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #3 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #4 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #5 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #6 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #7 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #8 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #9 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #10 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #11 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #12 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #13 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #14 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #15 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #16 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #17 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #18 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #19 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #20 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #21 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #22 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #23 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #24 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #25 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #26 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #27 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #28 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #29 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #30 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #31 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #32 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #33 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #34 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #35 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #36 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #37 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #38 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #39 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #40 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #41 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #42 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #43 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #44 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #45 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #46 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #47 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #48 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #49 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #50 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #51 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #52 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #53 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #54 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #55 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #56 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #57 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #58 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #59 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #60 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #61 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #62 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #63 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #64 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #65 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #66 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #67 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #68 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #69 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #70 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #71 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #72 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #73 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #74 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #75 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #76 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #77 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #78 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #79 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #80 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #81 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #82 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #83 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #84 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #85 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #86 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #87 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #88 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #89 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #90 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #91 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #92 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #93 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #94 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #95 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4759:32)
I/flutter ( 4768): #96 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #97 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #98 _TheatreElement.mount (package:flutter/src/widgets/overlay.dart:493:16)
I/flutter ( 4768): #99 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #100 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #101 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #102 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #103 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #104 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #105 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #106 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #107 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #108 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #109 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #110 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #111 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #112 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #113 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #114 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #115 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #116 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #117 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #118 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #119 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #120 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #121 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #122 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #123 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #124 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #125 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #126 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #127 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #128 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #129 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #130 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #131 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #132 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #133 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #134 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #135 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #136 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #137 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #138 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #139 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #140 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #141 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #142 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #143 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #144 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #145 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #146 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #147 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #148 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #149 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #150 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #151 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #152 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #153 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #154 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #155 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #156 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #157 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #158 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #159 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #160 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #161 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4654:14)
I/flutter ( 4768): #162 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #163 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #164 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #165 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #166 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #167 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #168 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #169 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #170 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #171 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #172 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #173 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #174 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #175 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #176 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #177 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #178 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #179 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #180 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #181 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #182 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #183 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #184 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #185 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #186 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #187 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #188 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #189 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #190 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #191 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #192 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #193 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #194 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #195 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #196 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #197 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #198 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #199 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #200 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #201 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #202 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #203 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #204 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #205 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #206 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #207 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #208 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #209 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #210 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #211 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #212 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #213 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #214 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #215 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #216 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #217 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #218 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3769:11)
I/flutter ( 4768): #219 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #220 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #221 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #222 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3653:16)
I/flutter ( 4768): #223 Element.rebuild (package:flutter/src/widgets/framework.dart:3495:5)
I/flutter ( 4768): #224 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3622:5)
I/flutter ( 4768): #225 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3617:5)
I/flutter ( 4768): #226 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2907:14)
I/flutter ( 4768): #227 Element.updateChild (package:flutter/src/widgets/framework.dart:2710:12)
I/flutter ( 4768): #228 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:857:16)
I/flutter ( 4768): #229 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:828:5)
I/flutter ( 4768): #230 RenderObjectToWidgetAdapter.attachToRenderTree. (package:flutter/src/widgets/binding.dart:774:17)
I/flutter ( 4768): #231 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2222:19)
I/flutter ( 4768): #232 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:773:13)
I/flutter ( 4768): #233 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:662:7)
I/flutter ( 4768): #234 runApp (package:flutter/src/widgets/binding.dart:704:7)
I/flutter ( 4768): #235 main (file:///Users/zheng/Documents/android_project/hi_flutter/lib/main.dart:19:16)
I/flutter ( 4768): #236 _startIsolate. (dart:isolate/runtime/libisolate_patch.dart:279:19)
I/flutter ( 4768): #237 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)
I/flutter ( 4768): ══════════════════════════════════════════════════════════

[willlarche]

Hi, @Zheng-Shuo , I can't reproduce this. Can you let me know which code you're running? Is it from the 103 starter branch? or did you complete 102 on your own and you're running off that?

[Zheng-Shuo]

Hi, @willlarche , thank you for your reply, I think I probably know where I was wrong,
when i write it like this I‘ll get the error:

import 'package:Shrine/model/data.dart';
import 'package:Shrine/model/product.dart';

and when i write it like this, it's working fine:

import 'model/data.dart';
import 'model/product.dart';

I don't know why, could you explain it?

[redbrogdon]

Dart considers these two imports:

import 'package:Shrine/model/data.dart';

import 'model/data.dart';

To be different libraries, even if they ultimately point to the same file. So if you import the data.dart file both ways inside a single app, the compiler will think you've imported it twice, and give it two different namespaces with two different sets of classes. That's why you saw an error that said:

A value of type 'dart.core::List<#lib1::Product>' can't be assigned 
to a variable of type 'dart.core::List<#lib2::Product>'.

As far as the compiler knew, you were using two different classes called Product from two different libraries, and the cast failed.

The easiest way to fix this is just to be consistent about how you import things. I generally use the package prefix for everything, personally.

[Zheng-Shuo]

@redbrogdon @willlarche
I see. Thank you for your help!