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Flutter中用ListView嵌套GridView报错异常

flutter中的ListView组件和GridView组件都是常用的布局组件,有时候ListView中需要嵌套GridView来使用,例如下图:

这种情况就需要在ListView里面再嵌套一个GridView用于排放图片等信息,先来看一下GridView一些常用的参数

GridView.count(
  crossAxisCount: 3,                            // 每行显示多少个
  crossAxisSpacing: 1.5,                        // 横轴网格间距
  mainAxisSpacing: 1.5,                         // 纵轴网格间距
  childAspectRatio: 11/16,                      // 网格比例
)

在GridView中的元素无法设置其宽高,主要通过childAspectRatio来设置其比例,通过比例来显示其大小。

在项目中如果直接使用ListView嵌套GridView进行布局,其会出现报错异常,例如下面异常:

I/flutter ( 5969): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 5969): The following assertion was thrown during performResize():
I/flutter ( 5969): Vertical viewport was given unbounded height.
I/flutter ( 5969): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter ( 5969): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter ( 5969): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter ( 5969): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter ( 5969): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter ( 5969): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter ( 5969): the height of the viewport to the sum of the heights of its children.

  

出现这种情况可在GridView中设置shrinkWrap:true即可解决:

GridView.count(
  shrinkWrap:true,                              // 处理listview嵌套报错
),

  

此时有可能出现手指在GridView区域滑动时ListView无法进行滚动,处理该问题可在GridView中设置physics: NeverScrollableScrollPhysics()来处理:

GridView.count(
  physics: NeverScrollableScrollPhysics(),      // 处理GridView中滑动父级Listview无法滑动
)

  

posted @ 2019-06-14 17:09  天天饱  阅读(3562)  评论(6编辑  收藏  举报