Vertical viewport was given unbounded height

Question

This is my code:

  @override
  Widget build(BuildContext context) {
    return new Material(
      color: Colors.deepPurpleAccent,
      child: new Column(
           


        

Answer 1

This answer is based on the north of the @CopsOnRoad

This happens because the ListView/GridView widget has no parent to take its size , so its height is infinite and is the flutter does not know the height of the ListView and cannot render.

1. Solution one: fixed height

   Wrap it up directly with the Container or SizedBox to write the dead height.

   Column(
     children: [
       SizedBox(
        height: 400, // fixed height
       child: ListView(...),
      ),
    ],
   )
   

This is fine, but if the height needs to be adaptive, it will not work if you write it.

2. Solution two: shrinkWrap: true

   Try shrinkWrap: true with physics: ScrollPhysics() for scrolling

   shrinkWrap: true is a bit like in android's wrap_content.

   ListView.builder(
      scrollDirection: Axis.vertical,
      shrinkWrap: true,
      physics: ScrollPhysics()
   ...
   

However, after compiling, you will find a long yellow warning at the bottom of the page.

So still can't

3. Solution three: Expanded or Flexible

   Flexible Is a flexible layout in flutter, equivalent to LinearLayout in android.

   There is one in Flexible flex The attribute, equal to layout_weight, takes up all the remaining space.

   So, we can wrap the ListView with Flexible.

   Column(
     children: [
       Expanded( 
         child: ListView(...),
       ),
     ],
   )
   

This answer based :Vertical viewport was given unbounded height.