無法在PageView上查看第一項

我正在嘗試創建與我的物件相關的 PageView，但是當我加載時，第一個專案沒有顯示。它像螢屏截圖中一樣是空白的。列印功能作業正常，它列印現有專案但我無法查看它。

列印結果 item : itemfirst

 Scaffold(
        backgroundColor: colordtmainone,
        body: NestedScrollView(
          controller: _scrollController,
          headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
            return <Widget>[
            SliverAppBar(
                floating: true,
                elevation: 0,
                backgroundColor: colordtmainone,
                toolbarHeight: 0,
                expandedHeight: 0,
                forceElevated: innerBoxIsScrolled,
              ),
            ];
          },
          body:  PageView.builder(
            onPageChanged: (indexpage){
              if (indexpage   1 == _userservicesForDisplay.length) {
                page = page  1;
                _loadmoreuserservices();
              }
            },
            scrollDirection: Axis.vertical,
            physics: ClampingScrollPhysics(),
            itemBuilder: (context, index) {
         for(final item in _userservicesForDisplay)print('item: ${item.service}');
              return index == 0 ? SizedBox(height:0,width:0) : _listItemUserService(index-1);},
            itemCount: _userservicesForDisplay.length 1,
          ),
        ),
      )

uj5u.com熱心網友回復：

在這里，您正在跳過第一個元素。如果index = 0，則回傳一個 SizedBox(height:0,width:0)。

return index == 0 ? SizedBox(height:0,width:0) : _listItemUserService(index-1);},

所以你可以

itemBuilder: (_, index) {
   return _listItemUserService(index);
},
itemCount: _userservicesForDisplay.length,

uj5u.com熱心網友回復：

you can use this code for your reference hope this will work for you thanks


import 'package:flutter/material.dart';
import 'package:traveling/helpers/AppColors.dart';
import 'package:traveling/screens/Employee/home/Home.dart';
import 'package:traveling/screens/Employee/profile/Profile.dart';
import 'package:traveling/screens/Employee/setting/Setting.dart';



class EmployeeBottomNavBar extends StatefulWidget {
  const EmployeeBottomNavBar({Key? key}) : super(key: key);

  @override
  _EmployeeBottomNavBarState createState() => _EmployeeBottomNavBarState();
}

class _EmployeeBottomNavBarState extends State<EmployeeBottomNavBar> {
  int pageIndex = 0;
  bool visible = true;

  List<Widget> pageList = <Widget>[EmployeeHome(), EmployeeProfile(leadingIcon: false,), Setting()];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: pageList[pageIndex],
        bottomNavigationBar: BottomNavigationBar(
            fixedColor: Colors.redAccent[400],
            currentIndex: pageIndex,
            onTap: (value) {
              setState(() {
                pageIndex = value;
              });
            },
            // type: BottomNavigationBarType.fixed,
            items: [
              BottomNavigationBarItem(

                  activeIcon: Container(
                    height: 40,
                    width: 80,
                    decoration: BoxDecoration(
                      shape: BoxShape.circle,
                      color: Color(0xff2161c0),
                    ),
                    child: Icon(
                      Icons.home,
                      color: AppColors.white,
                    ),
                  ),
                  icon: Icon(
                    Icons.home,
                    color: Color(0xff2161c0),
                  ),
                  label: ""),
              BottomNavigationBarItem(
                  activeIcon: Container(
                    height: 40,
                    width: 80,
                    decoration: BoxDecoration(
                      shape: BoxShape.circle,
                      color: Color(0xff2161c0),
                    ),
                    child: Icon(
                      Icons.person,
                      color: AppColors.white,
                    ),
                  ),
                  icon: Icon(
                    Icons.person,
                    color: AppColors.baseLightBlueColor,
                  ),
                  label: ""),
              BottomNavigationBarItem(
                  activeIcon: Container(
                    height: 40,
                    width: 80,
                    decoration: BoxDecoration(
                      shape: BoxShape.circle,
                      color: AppColors.baseLightBlueColor,
                    ),
                    child: Icon(
                      Icons.settings,
                      color: AppColors.white,
                    ),
                  ),
                  icon: Icon(
                    Icons.settings,
                    color: AppColors.baseLightBlueColor,
                  ),
                  label: ""),
            ]
        )
    );
  }
}

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