引发了另一个异常： RenderBox 未布置：CustomRenderShrinkWrappingViewport#f6727 relayoutBoundary=up17 NEEDS-PAINT N

Posted 2023-02-23

【中文标题】引发了另一个异常： RenderBox 未布置：CustomRenderShrinkWrappingViewport#f6727 relayoutBoundary=up17 NEEDS-PAINT NEEDS-COMPOSITING

【英文标题】：Another exception was thrown: RenderBox was not laid out: CustomRenderShrinkWrappingViewport#f6727 relayoutBoundary=up17 NEEDS-PAINT NEEDS-COMPOSITING

【发布时间】：2022-01-19 12:38:46

【问题描述】：

我需要水平生成一个列表。但是，我面临以下问题：

发生异常时正在处理以下 RenderObject 解雇：CustomRenderShrinkWrappingViewport#f6727 relayoutBoundary=up17 需要-布局需要-油漆需要-合成-位-更新：需要 合成创建者：CustomShrinkWrappingViewport ← IgnorePointer-[GlobalKey#952f0] ← 语义 ← 监听器 ← _GestureSemantics ← RawGestureDetector-[LabeledGlobalKey#f0fc7] ← 监听器 ← _ScrollableScope ← _ScrollSemantics-[GlobalKey#c0651] ← RepaintBoundary ← CustomPaint ← RepaintBoundary ← ⋯ parentData：（可以使用大小）约束：BoxConstraints(0.0 RangeMaintainingScrollPhysics, IdleScrollActivity#d7dd2, ScrollDirection.idle) 锚点：0.0 此 RenderObject 具有以下后代（显示深度为 5）： 子 0：RenderSliv​​erPadding#963bb 需要-布局需要-绘制需要-合成-位更新 孩子：RenderSliv​​erList#5357f 需要-布局需要-油漆 孩子 1：RenderSliv​​erPadding#2291f 需要 - 布局需要 - 油漆需要 - 合成 - 位更新 child: RenderSliv​​erList#6db77 需要-布局需要-油漆══════════════════════════════════ ══════════════════════════════════════════════════ ═══════════

抛出了另一个异常：RenderBox 未布局： CustomRenderShrinkWrappingViewport#f6727 relayoutBoundary=up17 需要-油漆需要-合成-位-更新

代码是：

CustomScrollView(
      // physics: ScrollPhysics(),
      scrollDirection: Axis.vertical,

      slivers: [
        SliverList(
          delegate: SliverChildBuilderDelegate(
            (context, index) => ScrollablePositionedList.builder(
              shrinkWrap: true,
              scrollDirection: Axis.horizontal,
              itemScrollController: _scrollController,
              itemCount: dummyQuestions.length,
              itemBuilder: (context, index) 
              currentPageIndex = index;
              return dummyQuestions[index];
              ,
            ),
          ),
        ),
      ],
    ),

【参考方案1】：

请参考以下代码：

CustomScrollView(
      controller: scrollController,
      scrollDirection: Axis.horizontal,
      slivers: <Widget>[
        SliverList(
          delegate: SliverChildBuilderDelegate(
            (_, int index) 
             return Container(
             child: Text(list[index]['index'],),
             );
            ,
            childCount: list.length,
          )
        ),
      ],
    ))