附加到多个滚动视图的页面视图控制器

Question

我的页面视图有问题，它在第一次初始化时工作正常（我的意思是当从“屏幕 A”打开包含页面视图的屏幕时，然后从另一个名为“屏幕”的屏幕打开“pageView 屏幕” B") 第二次遇到这个问题

我认为这个问题的发生是因为控制器再次重新初始化，但我处理了控制器并在处理屏幕时使其等于 null

ScrollController attached to multiple scroll views.
'package:flutter/src/widgets/scroll_controller.dart':
package:flutter/…/widgets/scroll_controller.dart:1
Failed assertion: line 109 pos 12: '_positions.length == 1'

使用provider 来处理tabBar 和Page View 的变化，provider 下面的代码class

class PageViewProvider extends BaseViewModel {
  // Tabs Controller
  int selectedTapIndex = 0;
  PageController? pageViewController;
  initPageIndex(int index) {
    if (pageViewController != null) {
      pageViewController = null;
    }
    print('init index $index');
    selectedTapIndex = index;
    pageViewController = PageController(initialPage: index, keepPage: false);
  }

  void changeSelectedTapIndex(int index) {
    selectedTapIndex = index;
    setState(ViewState.Idle);
  }

  void changePageView(int index) {
    pageViewController!.jumpToPage(index);
  }
}

这是带有 onTap 功能的选项卡项小部件，用于更改 TabBar 的索引

Consumer<PageViewProvider>(
    builder: (context, pageViewProvider, _) => Container(
          padding: const EdgeInsets.symmetric(horizontal: 10),
          child: Column(
            children: [
              Icon(
                iconData,
                color:
                    pageViewProvider.selectedTapIndex == selectedIndex
                        ? purpleColor
                        : grey500,
              ),
              normal14Text(
                title,
                color:
                    pageViewProvider.selectedTapIndex == selectedIndex
                        ? purpleColor
                        : grey500,
              ),
            ],
          ),
        ).onTap(() {
          pageViewProvider.changeSelectedTapIndex(selectedIndex!);
          pageViewProvider.changePageView(selectedIndex!);
        }));

至少，这是 pageView body

Consumer<PageViewProvider>(
    builder: (context, pageViewProvider, _) => PageView(
      controller: pageViewProvider.pageViewController,
      onPageChanged: (index) {
        pageViewProvider.changeSelectedTapIndex(index);
      },
      pageSnapping: true,
      children: [
        LeadProfileContent(),
        LeadProfileTimeLine(),
        LeadProfileCases(),
        LeadProfileDeals(),
      ],
    ),
  ),

提前致谢。

Answer 1

解决了。这里的问题与页面视图正文上方的消费者有关。刚刚删除它，然后像这样访问pageViewController：

context.read<PageViewProvider>.pageViewController

附加到多个滚动视图的页面视图控制器

Page view controller attached to multiple scroll view

mobile-application

dart

hybrid-mobile-app