app/lib/paegs/root_page/root_page_view.dart

import 'package:bbyyy/my_tools/event_bus.dart';
import 'package:bbyyy/my_tools/my_colors.dart';
import 'package:bbyyy/my_tools/my_tools.dart';
import 'package:bbyyy/paegs/release_goods_page/release_goods_page.dart';
import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';

class RootPageView {
//私有构造函数
  RootPageView._internal();

  //保存单例
  static RootPageView _singleton = RootPageView._internal();

  //工厂构造函数
  factory RootPageView() => _singleton;
  bool toTop = false;

  var bNText = ['首页', '货帮', '消息', '我的', '顶部'];
  var bNTextIcon = [
    ['images/svg/发现1.svg', 'images/svg/发现2.svg', 'images/svg/顶部.svg'],
    ['images/svg/货帮1.svg', 'images/svg/货帮2.svg'],
    ['images/svg/消息1.svg', 'images/svg/消息2.svg'],
    ['images/svg/我的1.svg', 'images/svg/我的2.svg']
  ];
  int bNIndex = 0;

  bottomNavigationBar1() {
    return StatefulBuilder(
      builder: (BuildContext context, void Function(void Function()) setState) {
        EventBus().on('ChangePage', (arg) {
          setState(() {});
        });
        return Stack(
          alignment: Alignment.bottomCenter,
          children: [
            Container(
              height: 51,
              decoration: BoxDecoration(boxShadow: [
                BoxShadow(
                  color: MyColors.c7FE1E1E1,
                  blurRadius: 5.0,
                ),
              ]),
            ),
            Container(
              decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.all(Radius.circular(30)),
                  boxShadow: [
                    BoxShadow(
                      color: MyColors.c7FE1E1E1,
                      blurRadius: 5.0,
                    ),
                  ]),
              height: 60,
              width: 60,
            ),
            Container(
              color: Colors.white,
              height: 51,
              alignment: Alignment.center,
              child: Row(
                children: [
                  Expanded(
                    child: Row(
                      children: [
                        getButton(0),
                        getButton(1),
                      ],
                      mainAxisAlignment: MainAxisAlignment.spaceAround,
                    ),
                  ),
                  Container(
                    width: 60,
                  ),
                  Expanded(
                    child: Row(
                      children: [
                        getButton(2),
                        getButton(3),
                      ],
                      mainAxisAlignment: MainAxisAlignment.spaceAround,
                    ),
                  )
                ],
              ),
            ),
            GestureDetector(
              onTap: () {
                MyTools().toPage(context, ReleaseGoodsPage(null), (then) {});
              },
              child: Container(
                decoration: BoxDecoration(
                    color: Colors.white,
                    borderRadius: BorderRadius.all(Radius.circular(30))),
                height: 60,
                width: 60,
                alignment: Alignment.center,
                child: SvgPicture.asset(
                  'images/svg/发布.svg',
                  height: 44,
                  width: 44,
                ),
              ),
              behavior: HitTestBehavior.translucent,
            )
          ],
        );
      },
    );
  }

  bottomNavigationBar() {
    return StatefulBuilder(
      builder: (BuildContext context, void Function(void Function()) setState) {
        EventBus().on('ChangePage', (arg) {
          setState(() {});
        });
        return Container(
          height: 51,
          decoration: BoxDecoration(boxShadow: [
            BoxShadow(
              color: MyColors.c7FE1E1E1,
              blurRadius: 5.0,
            ),

          ],color: Colors.white,),
          alignment: Alignment.center,
          child: Row(
            children: [
              getButton(0),
              getButton(1),
              getButton(2),
              getButton(3),
            ],
          ),
        );
      },
    );
  }

  getButton(int i) {
    return Expanded(
      child: GestureDetector(
        onTap: () {
          if (bNIndex == 0 && toTop && i == 0) {
            toTop = false;
            EventBus().emit('toTop');
          }
          bNIndex = i;
          EventBus().emit('ChangePage');
        },
        behavior: HitTestBehavior.translucent,
        child: Padding(
          padding: EdgeInsets.only(left: 10, right: 10),
          child: Column(
            children: [
              Container(
                child: SvgPicture.asset(bNIndex == 0 && toTop && i == 0
                    ? bNTextIcon[i][2]
                    : bNTextIcon[i][bNIndex == i ? 0 : 1]),
                height: 20,
                width: 20,
              ),
              Text(
                bNIndex == 0 && toTop && i == 0 ? bNText[4] : bNText[i],
                style: TextStyle(
                    color: bNIndex == i ? MyColors.cFF4233 : MyColors.c999999,
                    fontSize: 10),
              )
            ],
            mainAxisAlignment: MainAxisAlignment.center,
          ),
        ),
      ),
    );
  }
}