[解決済み] SingleChildScrollViewでExpandedを使用するには？

質問

使用方法 Expanded で SingleChildScrollView ? という画面があるのですが Image.network , ListView.builder と Row ( TextFormField と IconButton ). 私は ListView を Expanded . このカラムを SingleChildScrollView ? キーボードを開いているときに画面を移動して、書いている内容を確認したいのですが。カラムを折り返すと、このようなエラーが発生します。

      body: SingleChildScrollView(
        child: Column(
          children: <Widget>[
            Container(
              child: GestureDetector(
                child:
                Image.network(
                  postOne.imageUrl,
                  fit: BoxFit.fitWidth,
                  height: MediaQuery
                      .of(context)
                      .size
                      .width,
                  width: MediaQuery
                      .of(context)
                      .size
                      .width,
                ),
                onLongPress: () {},
                onDoubleTap: () {},
              ),
            ),
            Expanded(
              //height: MediaQuery.of(context).size.width*0.33,
              child: ListView.builder(
                  itemCount: commentList.length,
                  itemBuilder: (context, position) {
                    return GestureDetector(
                        onLongPress: () {},
                        child: Card(
                          child: Padding(
                            padding: EdgeInsets.all(5.0),
                            child: new CheckboxListTile(
                                title: new Text(commentList
                                    .elementAt(position)
                                    .coment,
                                  style: TextStyle(fontSize: 18.0),),
                                value: values[commentList
                                    .elementAt(position)
                                    .coment],
                                onChanged: (bool value) {}),
                          ),
                        )
                    );
                  }
              ),
            ),
            Container(
              child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    new Flexible(
                      child: Theme(
                        data: new ThemeData(
                            brightness: Brightness.light,
                            primarySwatch: Colors.grey,
                            inputDecorationTheme: new InputDecorationTheme(
                              labelStyle: new TextStyle(
                                  color: Colors.black45, fontSize: 18.0
                              ),
                            )
                        ),
                        child: new Form(
                          key: _formKey,
                          child: new TextFormField(
                            validator: (value) {
                              if (value.isEmpty) {
                                return 'Please enter the comment';
                              }
                            },
                            controller: commentController,
                            decoration: new InputDecoration(
                              labelText: "Add comment",
                              //hintText: 'Add comment'
                            ),
                            keyboardType: TextInputType.text,
                          ),
                        ),
                      ),
                    ),
                    new Container(
                        margin: EdgeInsets.only(left: 10.0, top: 12.0),
                        child: new IconButton(
                            icon: new Icon(Icons.send, color: Colors.black,),
                            onPressed: () {}
                        )
                    ),
                  ]),
            ),
          ],
        ),
      ),

I/flutter ( 6816): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 6816): The following assertion was thrown during performLayout():
I/flutter ( 6816): RenderFlex children have non-zero flex but incoming height constraints are unbounded.
I/flutter ( 6816): When a column is in a parent that does not provide a finite height constraint, for example if it is
I/flutter ( 6816): in a vertical scrollable, it will try to shrink-wrap its children along the vertical axis. Setting a
I/flutter ( 6816): flex on a child (e.g. using Expanded) indicates that the child is to expand to fill the remaining
I/flutter ( 6816): space in the vertical direction.
I/flutter ( 6816): These two directives are mutually exclusive. If a parent is to shrink-wrap its child, the child
I/flutter ( 6816): cannot simultaneously expand to fit its parent.
I/flutter ( 6816): Consider setting mainAxisSize to MainAxisSize.min and using FlexFit.loose fits for the flexible
I/flutter ( 6816): children (using Flexible rather than Expanded). This will allow the flexible children to size
I/flutter ( 6816): themselves to less than the infinite remaining space they would otherwise be forced to take, and
I/flutter ( 6816): then will cause the RenderFlex to shrink-wrap the children rather than expanding to fit the maximum
I/flutter ( 6816): constraints provided by the parent.
I/flutter ( 6816): The affected RenderFlex is:
I/flutter ( 6816):   RenderFlex#9f534 relayoutBoundary=up11 NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 6816): The creator information is set to:
I/flutter ( 6816):   Column ← _SingleChildViewport ← IgnorePointer-[GlobalKey#3670d] ← Semantics ← Listener ←
I/flutter ( 6816):   _GestureSemantics ← RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#4878e] ←
I/flutter ( 6816):   Listener ← _ScrollableScope ← _ScrollSemantics-[GlobalKey#c5885] ← RepaintBoundary ← CustomPaint ←
I/flutter ( 6816):   ⋯
I/flutter ( 6816): The nearest ancestor providing an unbounded width constraint is:
I/flutter ( 6816):   _RenderSingleChildViewport#155d8 relayoutBoundary=up10 NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 6816):   creator: _SingleChildViewport ← IgnorePointer-[GlobalKey#3670d] ← Semantics ← Listener ←
I/flutter ( 6816):   _GestureSemantics ← RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#4878e] ←
I/flutter ( 6816):   Listener ← _ScrollableScope ← _ScrollSemantics-[GlobalKey#c5885] ← RepaintBoundary ← CustomPaint ←
I/flutter ( 6816):   RepaintBoundary ← ⋯
I/flutter ( 6816):   parentData: <none> (can use size)
I/flutter ( 6816):   constraints: BoxConstraints(0.0<=w<=440.8, 0.0<=h<=649.3)
I/flutter ( 6816):   size: MISSING
I/flutter ( 6816): See also: https://flutter.dev/layout/
I/flutter ( 6816): If this message did not help you determine the problem, consider using debugDumpRenderTree():
I/flutter ( 6816):   https://flutter.dev/debugging/#rendering-layer
I/flutter ( 6816):   http://docs.flutter.io/flutter/rendering/debugDumpRenderTree.html
I/flutter ( 6816): If none of the above helps enough to fix this problem, please don't hesitate to file a bug:
I/flutter ( 6816):   https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter ( 6816): 

<イグ

どのように解決するのですか？

答えは、エラー自体にあります。カラムがスクロール可能なビュー内にある場合、カラムはコンテンツを縮小して表示しようとしますが、あなたは Expanded をカラムの子として使用しているため、カラムがその子を縮めようとするのとは逆に動作しています。この 2 つのディレクティブが互いに完全に反対であるため、このエラーが発生するのです。

エラーログに記載されているように、以下を試してみてください。

以下の設定を検討してください。 mainAxisSize を MainAxisSize.min (列の場合)を使用し FlexFit.loose はフレキシブルに対応します。 Flexible よりも Expanded