RenderBox 没有布局：RenderUiKitView#ceff7 NEEDS-LAYOUT NEEDS-PAINT

问题描述

错误仅在 IOS 中，相同的代码在 Android 上运行流畅：

======== Exception caught by gesture library =======================================================
The following assertion was thrown while routing a pointer event:
RenderBox was not laid out: RenderUiKitView#ceff7 NEEDS-LAYOUT NEEDS-PAINT
'package:Flutter/src/rendering/Box.dart':
Failed assertion: line 1940 pos 12: 'hasSize'

代码：

import 'package:Flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:zippy_rider/states/map_state.dart';

class Testing extends StatefulWidget {
  @override
  _TestingState createState() => _TestingState();
}

class _TestingState extends State<Testing> {
  @override
  Widget build(BuildContext context) {
    final mapState = Provider.of<MapState>(context);
    return Scaffold(
      body: Stack(
        children: [
          Positioned(
              top: 50.0,right: 17.0,left: 12.0,child: Visibility(
                visible: true,//mapState.stackElementsVisibility,child: Container(
                  height: 55.0,width: double.infinity,decoration: Boxdecoration(
                    borderRadius: BorderRadius.circular(3.0),color: Colors.white,BoxShadow: [
                      BoxShadow(
                          color: Colors.grey,offset: Offset(1.0,1.0),blurRadius: 5.0,spreadRadius: 2.0)
                    ],),child: TextField(
                    cursorColor: Colors.black,controller: mapState.sourceController,onChanged: (bool) {
                      mapState.suggestions(bool);
                    },onEditingComplete: () {
                      mapState.clearSuggestion();
                    },decoration: Inputdecoration(
                      icon: Container(
                        child: Icon(Icons.location_on),margin: EdgeInsets.only(
                            left: 8.0,top: 0.5,bottom: 5),width: 5.0,height: 13,suffix: IconButton(
                          icon: Icon(
                            Icons.clear,size: 15.0,onpressed: () {
                            mapState.sourceController.clear();
                            mapState.clearfields();
                            mapState.clearSuggestion();
                          }),hintText: "pick up",border: InputBorder.none,contentPadding: EdgeInsets.only(
                          left: 6.0,top: 8.0,right: 6.0),)),Positioned(
              left: 12,right: 17,top: 100,child: Column(
                children: [
                  SizedBox(
                    height:200.0,child: Scrollbar(
                      thickness: 10.0,radius: Radius.circular(10.0),isAlwaysShown: true,child: ListView.builder(
                        itemCount: mapState.suggestion.length,padding: EdgeInsets.all(0.0),itemBuilder: (context,index) {
                          if (mapState.suggestion.isNotEmpty) {
                            return Card(
                              margin: EdgeInsets.only(bottom: 1.0),child: ListTile(
                                title: Text(
                                  mapState.suggestion[index],style: TextStyle(color: Colors.black),onTap: () {
                                  //mapState.suggestion.clear();
                                  mapState.clearfields();

                                  print(
                                      'SUGGESTION: ${mapState.suggestion}');
                                  mapState.clearSuggestion();
                                  print(
                                      'SUGGESTION: ${mapState.suggestion}');
                                },);
                          } else {
                            return Center(
                              child: Container(
                                child: CircularProgressIndicator(),);
                          }
                        },],);
  }
}

它与其他问题的不同之处： RenderUiKitView

我已经尝试过的：
https://flutteragency.com/how-to-solve-render-box-was-not-laid-out-in-flutter/
https://github.com/flutter/flutter/issues/47235

为什么不在 Github 上创建问题？：不知道这个问题是否可以重现。

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@）