listview - ExpansionTile 内的 ListView 不起作用

Question

listview 在 ExpansionTile 内不起作用

我试图在 ExpansionTile 中显示一个 listview.builder 但它会引发一些异常

Card(
       child: ExpansionTile(
           leading: Icon(
              Icons.stars,
              color: Colors.pinkAccent,
           ),
           title: Text('Reviews',
                  style: Theme.of(context).textTheme.title,
                          ),
                children: [
                    ListView.builder(
                        itemCount: 5,
                        itemBuilder: (_, i) {
                          return (Text('item $i'));
                     })
                   ],
             ),
     ),

我想实现这样的https://imgur.com/a/0lubABC

══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 8182): The following assertion was thrown during performResize():
I/flutter ( 8182): Vertical viewport was given unbounded height.
I/flutter ( 8182): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter ( 8182): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter ( 8182): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter ( 8182): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter ( 8182): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter ( 8182): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter ( 8182): the height of the viewport to the sum of the heights of its children.
I/flutter ( 8182): 

Answer 1

上述解决方案都没有按预期工作。所以我已经解决了这个问题。您需要在ExpansionTile子项中的Listview.builder()中使用它：

shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),

完整代码：

                ExpansionTile( 
                    onExpansionChanged: (e){
                      //Your code
                    },
                    title: Text("You title text"),
                    children: [
                    ListView.builder(
                     shrinkWrap: true,
                     physics: NeverScrollableScrollPhysics(),
                     scrollDirection: Axis.vertical,
                     itemCount: items.length,
                     itemBuilder: (BuildContext context, int index){
                     return Text(items[index]);
                      }
                   )
                      
                    ],
                  ),

Answer 2

您的垂直尺寸ListView是无限的，因此无法渲染。设置 to 的shrinkWrap属性ListView来true解决这个问题。

Answer 3

将收缩包装和控制器都添加到 ListView.builder

final ScrollController _scrollController = ScrollController();


    ListView.builder(
          controller: _scrollController,
           shrinkWrap: true,
    ...

Answer 4

解决shrinkWrap: true,在ListView参数中的使用。