颤振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

不幸的是，ListView没有内置的方法来scrollToIndex（）函数。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

（有关一般scrollToIndex问题，请参见 flutter / issues / 12319 自2017年以来，但仍没有当前计划）

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

，但是有另一种ListView确实支持scrollToIndex（如Slashbin所述 ）：

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

• ScrollablePositionedList
  
  
  
  
  • 依赖项： scrollable_positioned_list
  
  
  • ScrollablePositionedList
    • dependency: scrollable_positioned_list

    您可以像设置ListView一样来设置它，并且工作原理相同，只是现在您可以访问 ItemScrollController 可以做到：

    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}）
    
    
    • 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，该库是Google开发的，而不是Flutter核心团队开发的。）

    这篇关于颤振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！