Question

我正在构建一个应用程序，其中Home ui看起来像网格，当在网格用户的单个图块上点击时，将导航到另一个页面。但是无论何时发生错误都会引发。这是不考虑语法错误的代码。我没有使用任何英雄部件。虽然我收到此错误。.

     body: Container(
       child: GridView.count(
         crossAxisCount: 2,
         children: <Widget>[ 
           Card(
             child: InkWell(
               onTap: (){
                 print('tapped pnemonia');
                 Navigator.push(context, MaterialPageRoute(builder: (context)=> diagnosis()));
               },
               child: Center(
                 child: Column(
                   children: <Widget>[
                     Text('Pnemonia'),
                     Image.asset('assets/images/lungs.jpg'),
                   ],
                 ),
               ),
             ),
           ),
         ],
       ),
     ),
    );
  }
}

，输出错误如下：


I/flutter ( 6827): ├# Here is the subtree for one of the offending heroes: Hero
I/flutter ( 6827):
I/flutter ( 6827): When the exception was thrown, this was the stack:
I/flutter ( 6827): #0      Hero._allHeroesFor.inviteHero.<anonymous closure> (package:flutter/src/widgets/heroes.dart:265:11)
I/flutter ( 6827): #1      Hero._allHeroesFor.inviteHero (package:flutter/src/widgets/heroes.dart:276:8)
I/flutter ( 6827): #2      Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:295:21)
I/flutter ( 6827): #3      SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #4      Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #5      ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #6      Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #7      SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #8      Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #9      MultiChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5534:16)
I/flutter ( 6827): #10     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #11     SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #12     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #13     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #14     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #15     SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #16     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #17     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #18     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #19     MultiChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5534:16)
I/flutter ( 6827): #20     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #21     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #22     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #23     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #24     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #25     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #26     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #27     MultiChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5534:16)
I/flutter ( 6827): #28     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #29     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #30     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #31     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #32     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #33     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #34     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #35     SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #36     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #37     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #38     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #39     SingleChildRenderObjectElement.visitChildren (package:flutter/src/widgets/framework.dart:5433:14)
I/flutter ( 6827): #40     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #41     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #42     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #43     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #44     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #45     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #46     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): #47     ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4272:14)
I/flutter ( 6827): #48     Hero._allHeroesFor.visitor (package:flutter/src/widgets/heroes.dart:308:15)
I/flutter ( 6827): (elided 3 frames from package dart:async)
I/flutter ( 6827): 
I/flutter ( 6827): Another exception was thrown: There are multiple heroes that share the same tag within a subtree.

这是我运行版本时出现的错误。

Answer 1

可能已经晚了，但是，如果您仍然感到困惑。我通过在FloatingActionButtons中手动添加新属性heroTag解决了我的问题。

@override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.end,
      children: <Widget>[
        FloatingActionButton(
          heroTag: 1, // put something different with this
            onPressed: (){
              counterBloc.add(CounterEvent.increment);
            },
          child: Icon(Icons.add),
        ),
        FloatingActionButton(
          heroTag: 2, // put something different with this
          onPressed: (){
            counterBloc.add(CounterEvent.decrement);
          },
          child: Icon(Icons.remove),
        ),
      ],
    );
  }

希望对您有所帮助

Answer 2

当您尝试在一个小部件中使用多个multiple heroes on one route can't have the same tag时，可能会发生错误FloatingActionButtons。

根据heroTag中FloatingActionButton的文档：

应用于按钮的Hero小部件的标签。

默认为与其他浮动操作按钮匹配的标签。

如果您不想执行浮动操作，请将其显式设置为null   按钮以具有英雄标签。

如果未明确设置，则只能有一个   每条路线（即每个屏幕）的FloatingActionButton，否则   会有标签冲突（一条路线上的多个英雄不能有   相同的标签）。材料设计规范建议仅使用   每个屏幕一个浮动操作按钮。

要解决您的异常并在单个窗口小部件中使用多个FAB，请确保在FAB中为Unique传递heroTag对象/值/字符串。

注意：如果不将值传递给heroTag，它将创建默认值<default FloatingActionButton tag>。这对于所有FAB都是通用的。因此，如果它们在同一个小部件中，则将使用重复的heroTag并抛出异常。

如果您有任何疑问，请告诉我。

使用颤动中的手势检测器导航到其他页面时，颤动中的黑屏。说多个英雄共享同一标签

2 个答案: