Vertical viewport was given unbounded height

报错

I/flutter ( 5510): Vertical viewport was given unbounded height.
I/flutter ( 5510): Viewports expand in the scrolling direction to fill their container. In this case, a vertical
I/flutter ( 5510): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter ( 5510): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter ( 5510): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter ( 5510): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter ( 5510): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter ( 5510): the height of the viewport to the sum of the heights of its children.

在使用ListView报错

解决方案

return ListView(
        shrinkWrap: true, // 加上这个就不会因为高度问题报错
        children: navs,
      );