扑扑降价。在降价小部件上方和下方添加其他小部件时遇到问题

Question

我有一个Flutter应用，正在下拉网站使用的文本，因此以HTML格式设置。我正在使用flutter_markdown软件包0.2.0版将其转换为适合在我的应用中显示的格式化文本。

这一切都很好，但是，如果我尝试在Markdown小部件上方和/或下方添加小部件，则不会呈现文本，Flutter会引发以下错误：

flutter: ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
flutter: The following assertion was thrown during performResize():
flutter: Vertical viewport was given unbounded height.
flutter: Viewports expand in the scrolling direction to fill their container.In this case, a vertical
flutter: viewport was given an unlimited amount of vertical space in which to expand. This situation
flutter: typically happens when a scrollable widget is nested inside another scrollable widget.
flutter: If this widget is always nested in a scrollable widget there is no need to use a viewport because
flutter: there will always be enough vertical space for the children. In this case, consider using a Column
flutter: instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
flutter: the height of the viewport to the sum of the heights of its children.

将Markdown代码放入扩展的窗口小部件中是可行的，但是markdown部分会滚动，并且按钮（或扩展窗口小部件外部的任何窗口小部件）都固定在屏幕上，并且不会随文本滚动。

我想知道整个事情是否需要在Expanded内进行，但是那又需要在Column，Row或Flex内进行，然后只有一个孩子，而我有多个孩子。我对结构有点困惑。我确定我确实缺少一些明显的东西？！

此代码给出错误：

class _DetailScreenState extends State<DetailScreen> {
  GlobalKey<ScaffoldState> scaffoldState = GlobalKey();

  @override
    Widget build(BuildContext context) {
      return Scaffold(
          key: scaffoldState,
          backgroundColor: Color(0xffeeeeee),
          appBar: AppBar(
            elevation: 0,
            title: Text("Section Title", style: TextStyle(fontSize: 16.0, fontWeight: FontWeight.bold),)
          ),
          body:  Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[

            SizedBox(height: 20.0),

            FlatButton.icon(
              onPressed: _addToCalendar,
              padding: EdgeInsets.all(15.0),
              color: Color(0xffffd2b1),
              icon: Icon(Icons.calendar_today),
              label: const Text('Add to calendar', style: TextStyle(fontWeight:FontWeight.w300, fontSize: 15.0)),
            ),


            Markdown(data: widget.programme.description),

            FlatButton(
              onPressed: _triggerFunction,
              color: Color(0xffffd2b1),
              padding: EdgeInsets.all(20),
              child: Text('Button text here', style: TextStyle(fontFamily: 'roboto', fontWeight: FontWeight.bold, color: Colors.black87), textAlign: TextAlign.center,),
            ),

          ]
        ),
      );
    }
}

此代码将起作用...

class _DetailScreenState extends State<DetailScreen> {
  GlobalKey<ScaffoldState> scaffoldState = GlobalKey();

  @override
    Widget build(BuildContext context) {
      return Scaffold(
          key: scaffoldState,
          backgroundColor: Color(0xffeeeeee),
          appBar: AppBar(
            elevation: 0,
            title: Text("Section Title", style: TextStyle(fontSize: 16.0, fontWeight: FontWeight.bold),)
          ),
          body:  Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[

            SizedBox(height: 20.0),

            FlatButton.icon(
              onPressed: _addToCalendar,
              padding: EdgeInsets.all(15.0),
              color: Color(0xffffd2b1),
              icon: Icon(Icons.calendar_today),
              label: const Text('Add to calendar', style: TextStyle(fontWeight:FontWeight.w300, fontSize: 15.0)),
            ),

            Expanded(
                child: Markdown(data: widget.programme.description),
            ),

            FlatButton(
              onPressed: _triggerFunction,
              color: Color(0xffffd2b1),
              padding: EdgeInsets.all(20),
              child: Text('Button text here', style: TextStyle(fontFamily: 'roboto', fontWeight: FontWeight.bold, color: Colors.black87), textAlign: TextAlign.center,),
            ),

          ]
        ),
      );
    }
}

，但markdown部分滚动，按钮固定在屏幕上，并且不随文本滚动，这在我的应用程序的当前版本中还可以，但是客户端希望添加很多其他内容，所以我真的想能够拥有一个滚动区域，其中包含所有内容（包括降价）。