flutter-开发中，各种组件的应用场景【二】

Container组件嵌套chid【Container】，chid【Container】大小调整技巧

场景：有一个全局大小的父Container设置背景色，内部有一个子Container负责装配各种组件，有另一种背景色，且需随装配的组件自适应大小【用于弹出式遮盖层的布局】
问题：子Container会跟随父Container大小，无法自适应
技巧：如代码所示，使用Stack【或者Column，Algin，Center等组件】包一层

Container(
      width: ToolScreenWidth,
      height: ToolScreenHeight,
      color: Color.fromRGBO(0, 0, 0, 0.5),
      child: Stack(
        children: [
          Container(
            color: Colors.white,
            child: Column(
              mainAxisSize: MainAxisSize.min,
              mainAxisAlignment: MainAxisAlignment.start,
              children: [
                SizedBox(height: ToolStatusBarHeight,),
                Container(
                  width: ToolScreenWidth,
                  height: 70,
                  color: Colors.red,
                ),
                Container(
                  width: ToolScreenWidth,
                  height: 70,
                  color: Colors.yellow,
                ),
                Container(
                  width: ToolScreenWidth,
                  height: 90,
                  color: Colors.greenAccent,
                ),
              ],
            ),
          ),
        ],
      ),
    );

键盘遮盖输入框问题

场景：在键盘弹出时需要在键盘上附加一个工具view【Container】，在输入框【TextField】外层套一个滚动组件【SingleChildScrollView】，默认输入框会处理键盘遮盖问题【自动向上滚动】，但无法处理工具view的遮盖，在这里需要监听键盘的滚动事件，以及工具view的位置，和输入框的位置以及滚动组件的滚动位置，计算出差值，进行滚动。

输入框遮挡方案
///基础
import 'package:flutter/material.dart';
import 'package:firstproject/app/AppBarCustomBase.dart';

///工具
import 'package:firstproject/until/Tool.dart';

class CrosswordGameSetingPage extends StatefulWidget {
  final arguments;

  CrosswordGameSetingPage({this.arguments, Key? key}) : super(key: key) {
    print("看看页面参数---${this.arguments}");
  }

  @override
  State<CrosswordGameSetingPage> createState() =>
      _CrosswordGameSetingPageState();
}

class _CrosswordGameSetingPageState extends State<CrosswordGameSetingPage> with WidgetsBindingObserver {

  ScrollController _bgScrController = ScrollController();
  ///工具UI-GlobalKey
  GlobalKey _toolViewlKey = GlobalKey();
  ///输入框
  GlobalKey _filelKey = GlobalKey();

  ///初始化方法
  void initState() {
    super.initState();

    //监听滚动事件，打印滚动位置
    _bgScrController.addListener(() {
      print("滚动位置变化--${_bgScrController.offset}"); //打印滚动位置
    });

    ///监听键盘高度变化
    WidgetsBinding.instance.addObserver(this);

  }
///在页面高度发生变化的时候会触发该回调
  @override
  void didChangeMetrics() {
    super.didChangeMetrics();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      print('键盘高度---${MediaQuery.of(context).viewInsets.bottom}');
    });
  }

  ///析构
  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }
  Widget _getBodyWidget(BuildContext context) {
    
    return Container(
      width: ToolScreenWidth,
      height: ToolScreenHeight,
      color: Colors.white,
      child: Stack(
        alignment: Alignment.topCenter,
        children: [
          Positioned(
            child:Container(
              width: ToolScreenWidth,
              height: ToolScreenHeight,
              color: ToolColorRandomColor(),
              child: SingleChildScrollView(
                  controller: _bgScrController,
                child:Column(
                  children: [
                    Container(
                      width: ToolScreenWidth,
                      height: 300,
                      color: ToolColorRandomColor(),
                    ),
                    Container(
                      width: ToolScreenWidth,
                      height: 200,
                      color: ToolColorRandomColor(),
                    ),
                    Container(
                      width: ToolScreenWidth,
                      height: 40,
                      child: TextField(
                        key: _filelKey,
                        controller: TextEditingController(text: "输入框"),
                        onTap: (){
                          judgeKeyboardOverspreadTextFile();
                        },
                      ),
                    ),
                    Container(
                      width: ToolScreenWidth,
                      height: 200,
                      color: ToolColorRandomColor(),
                    ),

                  ],
                )),
            ),

          ),
          Positioned(
            bottom: 0,
            child: Container(
              key: _toolViewlKey,
              width: ToolScreenWidth,
              height: 100,
              color: Color.fromRGBO(0, 0, 0, 0.5),
              child: Text("工具栏"),
            ),
          )
        ],
      ),
    );
  }


  ///处理键盘遮盖问题
  void judgeKeyboardOverspreadTextFile() {
    Future.delayed(Duration(milliseconds: 800), () {
      final toolViewBox =
      this._toolViewlKey.currentContext?.findRenderObject() as RenderBox?;
      double boxY = toolViewBox?.localToGlobal(Offset.zero).dy ?? 0;

      print(
          "我想看看--提示view位置---${toolViewBox?.localToGlobal(Offset.zero)}---${toolViewBox?.size}");

      GlobalKey filelKey = _filelKey;
      final filebox = filelKey.currentContext?.findRenderObject() as RenderBox?;
      double fileboxY = filebox?.localToGlobal(Offset.zero).dy ?? 0;
      double fileboxHeight = filebox?.size.height ?? 0;
      print(
          "我想看看--file位置---${filebox?.localToGlobal(Offset.zero)}---${filebox?.size}");

      if (fileboxY + fileboxHeight >= boxY) {
        double? scroY =
            fileboxY - boxY + fileboxHeight + _bgScrController.offset + 10;
        this._bgScrController.animateTo(
          scroY,
          duration: Duration(milliseconds: 200),
          curve: Curves.ease,
        );
        print("我想看看--滚动位置---${scroY}---");
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: RawKeyboardListener(
        autofocus: true,
        onKey: (event) {
          print("键盘----event=${event.toString()}");
        },
        focusNode: FocusNode(),
        child: _getBodyWidget(context),
      ),
      appBar: AppBarCustomBase(
        barHeight: 100,
        backgroundImageName: 'assets/images/bg_375x90.png',
        leadingWidget: GestureDetector(
          child: Image.asset(
            'assets/images/icon_back.png',
            width: 66,
            height: 41,
            fit: BoxFit.cover,
          ),
          onTap: () {
            Navigator.of(context).pop();
          },
        ),
        trailingWidget: Image.asset(
          'assets/images/icon_share.png',
          width: 66,
          height: 41,
        ),
      ),
    );
  }
}