颤动 ListView 滚动到索引不可用 [英] flutter ListView scroll to index not available

问题描述

我需要什么:

我想按某个索引滚动列表，我该怎么做.

I want to scroll a list by some index, how can i do that.

我所知道的:

scrollToIndex 应该从 n 个索引开始，但是我们如何滚动到任何索引?

scrollToIndex should start from n index, but how can we scroll to any index?

推荐答案

遗憾的是，ListView 没有针对 scrollToIndex() 函数的内置方法.您必须开发自己的方法来测量 animateTo() 或 jumpTo() 元素的偏移量，或者您可以搜索这些建议的解决方案/插件或从其他帖子，例如 Flutter:滚动到 ListView 中的小部件

Unfortunately, ListView has no built-in approach to a scrollToIndex() function. You’ll have to develop your own way to measure to that element’s offset for animateTo() or jumpTo(), or you can search through these suggested solutions/plugins or from other posts like Flutter: Scrolling to a widget in ListView

(一般 scrollToIndex 问题在 flutter/issues/12319 中讨论自 2017 年以来，但仍然没有当前的计划)

(the general scrollToIndex issue is discussed at flutter/issues/12319 since 2017, but still with no current plans)

但是有一种不同类型的 ListView 确实支持 scrollToIndex(正如 Slashbin 提到的):

But there is a different kind of ListView that does support scrollToIndex (as mentioned by Slashbin):

• ScrollablePositionedList
  • 依赖:scrollable_positioned_list

  您的设置与 ListView 完全一样并且工作方式相同，除了您现在可以访问 ItemScrollController 这样做:

  You set it up exactly like ListView and works the same, except you now have access to a ItemScrollController that does:

  • jumpTo({index,alignment})
  • scrollTo({index,alignment,duration,curve})

  简化示例:

  ItemScrollController _scrollController = ItemScrollController();
  
  ScrollablePositionedList.builder(
    itemScrollController: _scrollController,
    itemCount: _myList.length,
    itemBuilder: (context, index) {
      return _myList[index];
    },
  )
  
  _scrollController.scrollTo(index: 150, duration: Duration(seconds: 1));
  

  (请注意，这个库是由 Google 开发的，而不是由 Flutter 核心团队开发的.)

  这篇关于颤动 ListView 滚动到索引不可用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！