Error: No named parameter with the name 'IndexedWidgetBuilder' in flutter

Question

在 flutter web 中得到这个错误。在PageView.builder并没有在flutter项目中如何使用IndexedWidgetBuilder。尝试使用 itembuilder(context, index) 但没有解决。不能在这些版本的 flutter 中使用 itemcount，itembuilder。

扑博士：

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 2.0.3, on Microsoft Windows [Version 10.0.19042.746], locale en-IN)
[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    ! Some Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses
[√] Chrome - develop for the web
[√] Android Studio (version 3.5)
[√] VS Code (version 1.52.1)
[√] Connected device (2 available)

代码：

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:website/references/ref.dart';

class Carousel extends StatefulWidget {
  @override
  _CarouselState createState() => _CarouselState();
}

class _CarouselState extends State<Carousel> {
  var _tag = "carousel.dart";

  /// [ref]
  Ref _ref = Ref();

  /// [slide images]
  final List<String> imgList = [
    "assets/slider/slide1.jpg",
    "assets/slider/slide2.jpeg",
    "assets/slider/slide3.jpeg",
    "assets/slider/slide4.jpeg",
    "assets/slider/slide5.jpg",
    "assets/slider/slide6.jpeg"
  ];

  /// [variable for carousel]
  final PageController _pageController = PageController(
    initialPage: 0,
    viewportFraction: 1,
  );

  int _currentPage = 0;

  @override
  void initState() {
    super.initState();
    try {
      Timer.periodic(Duration(seconds: 8), (Timer timer) {
        if (_currentPage < 5) {
          _currentPage++;
        } else {
          _currentPage = 0;
        }
      });
    } on Exception catch (e) {
      print("$_tag initState e : $e");
    }
  }

  @override
  void dispose() {
    super.dispose();
    _pageController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    double h = MediaQuery.of(context).size.height;
    double w = MediaQuery.of(context).size.width;

    print("$_tag h: $h");
    print("$_tag w: $w");

    return ListView(
      padding: _ref.paddnMargin.edgeInsets0,
      children: <Widget>[
        _buildImageCarosel(),
      ],
    );
  }

  // build image carosel
  Widget _buildImageCarosel() {
    Widget widget;
    try {
      widget = Container(
        height: MediaQuery.of(context).size.height / 1.5,
        width: MediaQuery.of(context).size.width,
        child: PageView.builder(
          scrollDirection: Axis.horizontal,
          controller: _pageController,
          onPageChanged: _onPageChanged,
          IndexedWidgetBuilder: _buildDynamicList,
        ),
      );
    } on Exception catch (e) {
      print("$_tag _buildImageCarosel e : $e");
    }
    return widget;
  }

  Widget _buildDynamicList() {
    return ListView.builder(
      scrollDirection: Axis.horizontal,
      padding: _ref.paddnMargin.edgeInsets0,
      IndexedWidgetBuilder: (context, index) {
        return Container(
          margin: _ref.paddnMargin.edgeInsets10A,
          child: Center(
            child: Image.asset(
              imgList[index],
              height: MediaQuery.of(context).size.height / 1.5,
              width: MediaQuery.of(context).size.width,
            ),
          ),
        );
      },
     
    );
  }

  _onPageChanged(int index) {
    setState(() {
      _currentPage = index;
    });
  }
}

错误信息：

lib/widgets/carousel.dart:122:11: Error: No named parameter with the name 'IndexedWidgetBuilder'.
          IndexedWidgetBuilder: _buildDynamicList,
          ^^^^^^^^^^^^^^^^^^^^
/C:/sdk/flutter/packages/flutter/lib/src/widgets/page_view.dart:661:3: Context: Found this candidate, but the arguments don't match.
  PageView.builder({
  ^^^^^^^^^^^^^^^^
lib/widgets/carousel.dart:140:7: Error: No named parameter with the name 'IndexedWidgetBuilder'.
      IndexedWidgetBuilder: (context, index) {
      ^^^^^^^^^^^^^^^^^^^^
/C:/sdk/flutter/packages/flutter/lib/src/widgets/scroll_view.dart:1154:3: Context: Found this candidate, but the arguments don't match.
  ListView.builder({
  ^^^^^^^^^^^^^^^^
Waiting for connection from debug service on Chrome...             23.0s
Failed to compile application.

不明白是什么问题

Answer 1

在您的 _buildDynamicList() 方法中将此 IndexedWidgetBuilder: (context, index) 更改为 itemBuilder: (context, index)。检查此 page 列表视图生成器的示例。

您将属性的类型与其名称混淆了。这就是错误消息试图传达的意思，即没有属性命名为 IndexedWidgetBuilder。属性名字是 itemBuilder.

同样在 PageViewBuilder 中将其替换为 itemBuilder。检查 here 以获取其文档。

Error: No named parameter with the name 'IndexedWidgetBuilder' in flutter

Error: No named parameter with the name 'IndexedWidgetBuilder' in flutter

dart

flutter

flutter-web