Flutter：“bool”类型不是“double”类型的子类型

Question

type \'bool\' is not a subtype of type \'double\'我在使用ListView.builderinside时遇到错误ExpansionTile。

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我能够看到扩展图块，但是当我单击扩展图块时，我收到了如上所述的错误。

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这是我的带有扩展图块的应用程序的屏幕截图 -

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这是扩展列表时抛出错误的屏幕截图 -

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下面是我的整个代码和错误日志。

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import \'package:flutter/material.dart\';\n\nvoid main() => runApp(MyApp());\n\n// Colors\n\nvar mainColor = Color(0xFF35393C);\nvar bgColor = Color(0xFF30313C);\n\nclass MyApp extends StatelessWidget {\n  @override\n  Widget build(BuildContext context) {\n    return new MaterialApp(\n      title: \'List of Items\',\n      theme: new ThemeData(brightness: Brightness.dark),\n      home: new Home(title: \'List of Items\'),\n    );\n  }\n}\n\nclass Home extends StatefulWidget {\n  Home({Key key, this.title}) : super(key: key);\n\n  final String title;\n  @override\n  _HomeState createState() => _HomeState();\n}\n\nclass _HomeState extends State<Home> {\n  bool success = false;\n\n  final ScrollController _scrollController = ScrollController();\n\n  static List<String> categories = [\'Test1\', \'Test1\', \'Test2\', \'Test3\', \'Test4\', \'Test5\', \'Test6\', \'Test7\', \'Test8\', \'Test9\', \'Test10\'];\n  static List<List<String>> subCategories = [\n    [\n      "Approved",\n      "Not Approved",\n      "Under Test"\n    ],\n    [\n      "The maximum level of brightness",\n      "Screen darker",\n      "Make screen the darkest"\n    ],\n    [\n      "Mute",\n      "Unmute"\n    ],\n    [\n      "Open the roof",\n      "Close the roof"\n    ],\n    [\n      "Windows1",\n      "Windows2",\n      "Windows3",\n      "Windows4",\n      "Open windows",\n      "Close windows"\n    ],\n    [\n      "Ac1",\n      "Ac2",\n      "Ac3",\n      "Ac4",\n      "Ac5",\n      "Ac6",\n      "Ac7",\n      "Ac8",\n      "Ac9",\n      "Ac10",\n      "Highest fan speed",\n      "Lowest fan speed"\n    ],\n    [\n      "Open setting",\n      "Help"\n    ],\n    [\n      "Windows1",\n      "Windows2",\n      "Windows3",\n      "Windows4",\n      "Open windows",\n      "Close windows"\n    ],\n    [\n      "Ac1",\n      "Ac2",\n      "Ac3",\n      "Ac4",\n      "Ac5",\n      "Ac6",\n      "Ac7",\n      "Ac8",\n      "Ac9",\n      "Ac10",\n      "Highest fan speed",\n      "Lowest fan speed"\n    ],\n    [\n      "Approved",\n      "Not Approved",\n      "Under Test",\n      "Ac1",\n      "Ac2",\n      "Ac3",\n      "Ac4",\n      "Ac5",\n      "Ac6",\n      "Ac7",\n      "Ac8",\n      "Ac9",\n      "Ac10",\n      "Highest fan speed",\n      "Lowest fan speed",\n      "Windows1",\n      "Windows2",\n      "Windows3",\n      "Windows4",\n      "Open windows",\n      "Close windows"\n    ],\n    [\n      "Windows1",\n      "Windows2",\n      "Windows3",\n      "Windows4",\n      "Open windows",\n      "Close windows"\n    ]\n  ];\n  static List<bool> activeCategories = List.filled(categories.length, false);\n\n  @override\n  Widget build(BuildContext context) {\n    return Scaffold(\n      backgroundColor: bgColor,\n      appBar: new AppBar(\n        title: new Center(child: new Text(widget.title, textAlign: TextAlign.center)),\n      ),\n      body: ListView.builder(\n        itemCount: categories.length,\n          itemBuilder: (context, index) {\n            return ExpansionTile(\n              title: Text(categories.elementAt(index)),\n              key: PageStorageKey<String>(categories.elementAt(index)),\n              children:<Widget>[\n                ListView.builder(\n                  controller: _scrollController,\n                  scrollDirection: Axis.horizontal,\n                  shrinkWrap: true,\n                  itemCount: subCategories.length,\n                  itemBuilder: (context, subIndex){\n                    return ListTile(\n                      title: new Text(subCategories.elementAt(index).elementAt(subIndex)),\n                    );\n                  },\n                ),\n              ],\n            );\n          }\n      ),\n    );\n  }\n}\n

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下面是我在执行代码时得到的日志。

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I/flutter (21943): \xe2\x95\x90\xe2\x95\x90\xe2\x95\xa1 EXCEPTION CAUGHT BY WIDGETS LIBRARY \xe2\x95\x9e\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\nI/flutter (21943): The following assertion was thrown building ListView(scrollDirection: horizontal,\nI/flutter (21943): ScrollController#eaec6(no clients), shrinkWrap: shrink-wrapping, dependencies: [Directionality,\nI/flutter (21943): MediaQuery]):\nI/flutter (21943): type \'bool\' is not a subtype of type \'double\'\nI/flutter (21943): \nI/flutter (21943): Either the assertion indicates an error in the framework itself, or we should provide substantially\nI/flutter (21943): more information in this error message to help you determine and fix the underlying cause.\nI/flutter (21943): In either case, please report this assertion by filing a bug on GitHub:\nI/flutter (21943):   https://github.com/flutter/flutter/issues/new?template=BUG.md\nI/flutter (21943): \nI/flutter (21943): The relevant error-causing widget was:\nI/flutter (21943):   ListView file:///path_to_file/main.dart:198:26\nI/flutter (21943): \nI/flutter (21943): When the exception was thrown, this was the stack:\nI/flutter (21943): #0      ScrollPosition.restoreScrollOffset (package:flutter/src/widgets/scroll_position.dart:384:20)\nI/flutter (21943): #1      new ScrollPosition (package:flutter/src/widgets/scroll_position.dart:108:7)\nI/flutter (21943): #2      new ScrollPositionWithSingleContext (package:flutter/src/widgets/scroll_position_with_single_context.dart:57:8)\nI/flutter (21943): #3      ScrollController.createScrollPosition (package:flutter/src/widgets/scroll_controller.dart:233:12)\nI/flutter (21943): #4      ScrollableState._updatePosition (package:flutter/src/widgets/scrollable.dart:332:29)\nI/flutter (21943): #5      ScrollableState.didChangeDependencies (package:flutter/src/widgets/scrollable.dart:341:5)\nI/flutter (21943): #6      StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4376:12)\nI/flutter (21943): #7      ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)\nI/flutter (21943): #8      Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)\nI/flutter (21943): #9      Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)\nI/flutter (21943): #10     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)\nI/flutter (21943): #11     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)\nI/flutter (21943): #12     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)\nI/flutter (21943): #13     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)\nI/flutter (21943): #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)\nI/flutter (21943): #15     MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5551:32)\nI/flutter (21943): #16     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)\nI/flutter (21943): #17     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)\nI/flutter (21943): #18     SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5452:14)\nI/flutter (21943): #19     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #20     SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5452:14)\nI/flutter (21943): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #22     RenderObjectElement.updateChildren (package:flutter/src/widgets/framework.dart:5161:32)\nI/flutter (21943): #23     MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5561:17)\nI/flutter (21943): #24     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #25     SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5452:14)\nI/flutter (21943): #26     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #27     SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5452:14)\nI/flutter (21943): #28     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #29     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)\nI/flutter (21943): #30     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)\nI/flutter (21943): #31     StatelessElement.update (package:flutter/src/widgets/framework.dart:4298:5)\nI/flutter (21943): #32     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #33     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)\nI/flutter (21943): #34     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)\nI/flutter (21943): #35     StatefulElement.update (package:flutter/src/widgets/framework.dart:4413:5)\nI/flutter (21943): #36     Element.updateChild (package:flutter/src/widgets/framework.dart:2977:15)\nI/flutter (21943): #37     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)\nI/flutter (21943): #38     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)\nI/flutter (21943): #39     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2432:33)\nI/flutter (21943): #40     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:773:20)\nI/flutter (21943): #41     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:283:5)\nI/flutter (21943): #42     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1102:15)\nI/flutter (21943): #43     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1041:9)\nI/flutter (21943): #44     SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:957:5)\nI/flutter (21943): #48     _invoke (dart:ui/hooks.dart:259:10)\nI/flutter (21943): #49     _drawFrame (dart:ui/hooks.dart:217:3)\nI/flutter (21943): (elided 3 frames from package dart:async)\nI/flutter (21943): \nI/flutter (21943): \xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\xe2\x95\x90\n\n

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Answer 1

这对我来说工作：

...键：PageStorageKey ...

来源： https ://github.com/flutter/flutter/issues/36539#issuecomment-561848176

Answer 2

试试这个:)

class _HomeState extends State<Home> {
      bool success = false;

      final ScrollController _scrollController = ScrollController();

      static List<String> categories = ['Test1', 'Test1', 'Test2', 'Test3', 'Test4', 'Test5', 'Test6', 'Test7', 'Test8', 'Test9', 'Test10'];
      static List<List<String>> subCategories = [
        [
          "Approved",
          "Not Approved",
          "Under Test"
        ],
        [
          "The maximum level of brightness",
          "Screen darker",
          "Make screen the darkest"
        ],
        [
          "Mute",
          "Unmute"
        ],
        [
          "Open the roof",
          "Close the roof"
        ],
        [
          "Windows1",
          "Windows2",
          "Windows3",
          "Windows4",
          "Open windows",
          "Close windows"
        ],
        [
          "Ac1",
          "Ac2",
          "Ac3",
          "Ac4",
          "Ac5",
          "Ac6",
          "Ac7",
          "Ac8",
          "Ac9",
          "Ac10",
          "Highest fan speed",
          "Lowest fan speed"
        ],
        [
          "Open setting",
          "Help"
        ],
        [
          "Windows1",
          "Windows2",
          "Windows3",
          "Windows4",
          "Open windows",
          "Close windows"
        ],
        [
          "Ac1",
          "Ac2",
          "Ac3",
          "Ac4",
          "Ac5",
          "Ac6",
          "Ac7",
          "Ac8",
          "Ac9",
          "Ac10",
          "Highest fan speed",
          "Lowest fan speed"
        ],
        [
          "Approved",
          "Not Approved",
          "Under Test",
          "Ac1",
          "Ac2",
          "Ac3",
          "Ac4",
          "Ac5",
          "Ac6",
          "Ac7",
          "Ac8",
          "Ac9",
          "Ac10",
          "Highest fan speed",
          "Lowest fan speed",
          "Windows1",
          "Windows2",
          "Windows3",
          "Windows4",
          "Open windows",
          "Close windows"
        ],
        [
          "Windows1",
          "Windows2",
          "Windows3",
          "Windows4",
          "Open windows",
          "Close windows"
        ]
      ];
      static List<bool> activeCategories = List.filled(categories.length, false);

      @override
      Widget build(BuildContext context) {
        return Scaffold(
          backgroundColor: bgColor,
          appBar: new AppBar(
            title: new Center(child: new Text(widget.title, textAlign: TextAlign.center)),
          ),
          body: ListView.builder(
              itemCount: categories.length,
              itemBuilder: (context, index) {
                return ExpansionTile(
                  title: Text(categories.elementAt(index)),
                  key: PageStorageKey<String>(categories.elementAt(index)),
                  children: subCategories[index].map((text){
                    return ListTile(title: Text(text),);
                  }).toList(),
                );
              }
          ),
        );
      }
    }

我希望它有帮助...