颤动 :- 键盘对焦时，布局会在底部溢出。

Question

我有下面的布局代码。

@override
Widget build(BuildContext context) {
return Material(
  child: Scaffold(

//        resizeToAvoidBottomPadding: false,
//        resizeToAvoidBottomInset: false,
    appBar: PreferredSize(
      preferredSize: Size.fromHeight(70),
      child: AppBar(
        centerTitle: true,
        title: AutoSizeText(
          meal['name'],
          minFontSize: 30,
          maxFontSize: 50,
        ),
        backgroundColor: Colors.black,
        elevation: 1,
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.add),
            onPressed: () => null,
          ),
        ],
      ),
    ),
    body: Builder(
      builder: (context) {
        return Container(
          color: Colors.black,
          alignment: Alignment.center,
          child: FractionallySizedBox(
            widthFactor: 0.85,
            child: Container(
              child: Column(
                children: <Widget>[
                  Spacer(flex: 1,),
                  Container(
                    margin: EdgeInsets.only(bottom: 50),
                    child: Column(
                      children: <Widget>[
                        Container(
                          decoration: BottomWhiteDecoration(6.0),
                          padding: EdgeInsets.only(bottom: 8.0),
                          child: Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: <Widget>[
                              Text(
                                'Servings: 1',
                                style: TextStyle(color: Colors.white),
                              ),
                            ],
                          ),
                        ),
                        Container(
                          child: Column(
                            children: <Widget>[
                              RowNutrimentalInfo('Calories', meal['calories'], showGram: false),
                              RowNutrimentalInfo('Protein', meal['macros']['proteins']),
                              RowNutrimentalInfo('Carbs', meal['macros']['carbs']),
                              RowNutrimentalInfo('Fat', meal['macros']['fats']),
                            ],
                          ),
                        )
                      ],
                    ),
                  ),
                Spacer(flex: 2,),
                  Container(
                    child: Column(
                      children: <Widget>[
                        Form(
                          key: this._mealFormKey,
                          child: Row(
                            children: <Widget>[
                              Expanded(
                                flex: 10,
                                child: TextFormField(...),
                              ),
                              Spacer(flex: 1,),
                              Expanded(
                                flex: 10,
                                child: TextFormField(...),
                              ),
                            ],
                          ),
                        ),
                        FractionallySizedBox(
                          widthFactor: .50,
                          child: OutlineButton(
                            borderSide: BorderSide(color: Colors.white),
                            color: Colors.black,
                            onPressed: _eatMeal,
                            child: Padding(
                              padding: EdgeInsets.all(20),
                              child: Text('Ok',
                                  style: TextStyle(color: Colors.white)),
                            ),
                          ),
                        )
                      ],
                    ),
                  ),
                  Spacer(flex: 2,),
                ],
              ),
            ),
          ),
        );
      },
    ),
  ),
);
}

然而，当我开始在其中一个文本字段中输入时，键盘会导致布局在底部溢出，如下图所示。

以下是我得到的错误以及它在手机上的显示方式。有什么办法可以解决这个问题吗？我看到过类似的问题，解决方法比如设置resizeToAvoidBottomPadding：false，对我来说并不适用，因为键盘还是覆盖了文字输入。

The following assertion was thrown during layout:
A RenderFlex overflowed by 45 pixels on the bottom.

The relevant error-causing widget was: 
Column file:///C:/Users/bolon/StudioProjects/macro_counter/lib/Meal.dart:92:26
The overflowing RenderFlex has an orientation of Axis.vertical.
The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and 
black striped pattern. This is usually caused by the contents being too big for the RenderFlex.
Consider applying a flex factor (e.g. using an Expanded widget) to force the children of the 
RenderFlex to fit within the available space instead of being sized to their natural size.
This is considered an error condition because it indicates that there is content that cannot be seen. 
If the content is legitimately bigger than the available space, consider clipping it with a ClipRect 
widget before putting it in the flex, or using a scrollable container rather than a Flex, like a 
ListView.

Answer 1

问题是你使用的是展开式widget，你看展开式widget是灵活的，它们会根据可用空间消耗和收缩。如果你不想这样，你需要指定一个高度。

所以我使用了 MediaQuery为其设置 widget 根据设备的分辨率，请查看下面的解决方案，我已经创建了你的代码的演示。

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutterlearningapp/colors.dart';

class HomeScreen extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return _HomeScreen();
  }
}

class _HomeScreen extends State<HomeScreen> {
  @override
  void initState() {
    super.initState();
  }
  @override
  Widget build(BuildContext context) {
    return Material(
        child: Scaffold(
      appBar: AppBar(
        title: Text("Demo Scroll"),
      ),
      body: Container(
        height: double.infinity,
        width: double.infinity,
        color: Colors.black,
        child: SingleChildScrollView(

            child: Column(

              children: <Widget>[
                Container(
                  height: MediaQuery.of(context).size.height*0.6,
                  child: Column(
                    children: <Widget>[
                      CommonWidget("Calories", "150"),
                      CommonWidget("Protein", "9g"),
                      CommonWidget("Carbs", "15g"),
                      CommonWidget("Fat", "25g"),
                    ],
                  ),
                ),
                Container(
                  height: MediaQuery.of(context).size.height * 0.4,
                  child: Align(
                    alignment: Alignment.topCenter,
                    child: Column(
                      children: <Widget>[
                        Row(
                          children: <Widget>[
                            Expanded(
                              child: TextField(
                                style: new TextStyle(color: Colors.white),
                                decoration: InputDecoration(
                                    enabledBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    focusedBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    labelText: "Serving"),
                              ),
                            ),
                            SizedBox(
                              width: 10.0,
                            ),
                            Expanded(
                              child: TextField(
                                style: new TextStyle(color: Colors.white),
                                decoration: InputDecoration(
                                    enabledBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    focusedBorder: OutlineInputBorder(
                                      borderSide: BorderSide(color: Colors.white),
                                    ),
                                    labelText: "Germs"),
                              ),
                            ),
                          ],
                        ),
                        SizedBox(
                          height: 10.0,
                        ),
                        OutlineButton(
                          borderSide: BorderSide(color: Colors.white),
                          color: Colors.black,
                          onPressed: () {},
                          child: Padding(
                            padding: EdgeInsets.all(20),
                            child: Text('   Ok  ',
                                style: TextStyle(color: Colors.white)),
                          ),
                        )
                      ],
                    ),
                  ),
                )




              ],
            ),
          ),
        ),

    ));
  }

  Widget CommonWidget(var name, var value) {
    return Padding(
      padding: EdgeInsets.all(15.0),
      child: Column(
        children: <Widget>[
          Row(
            children: <Widget>[
              Expanded(
                child: Text(
                  name,
                  style: TextStyle(fontSize: 16.0, color: Colors.white),
                ),
              ),
              Expanded(
                child: Align(
                  alignment: Alignment.centerRight,
                  child: Text(value,
                      style: TextStyle(fontSize: 16.0, color: Colors.white)),
                ),
              )
            ],
          ),
          Divider(
            color: Colors.white,
            height: 20.0,
          )
        ],
      ),
    );
  }
}

而输出的结果将是下面的例子

Answer 2

   Scaffold(
  resizeToAvoidBottomInset: true)

只需将其添加到你的代码中。