How to center grid button inside red container - flutter

Question

I want to center all grid button inside red container but it is showing big space at bottom of red container..how to solve this
Widget build(BuildContext context) {
return Center(
child: Container(
color: Colors.red,
height: MediaQuery.of(context).size.height*0.60,
width: MediaQuery.of(context).size.height*0.60,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: GridView.builder(
itemCount: 16,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 4),
itemBuilder: (context,index)=>
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(child: Center(child: Text(index.toString(),)),color: Colors.blue,),
)
,),
),
),
);
}

Answer 1

Widget build(BuildContext context) {
return Scaffold(
body: Container(
color: Colors.red,
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.height,
child: Center(
child: SizedBox(
height: MediaQuery.of(context).size.height * 0.6,
child: GridView.builder(
padding: EdgeInsets.all(16),
itemCount: 16,
gridDelegate:
SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 4),
itemBuilder: (context, index) => Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
child: Center(
child: Text(
index.toString(),
)),
color: Colors.blue,
),
),
),
),
),
),
);
}
You can wrap the gridview.builder inside a sized box ( provided some height ) and wrap it under Center widget.

Answer 2

You can do it like this :
Center(
child: Container(
color: Colors.red,
height: MediaQuery.of(context).size.height * 0.60,
width: MediaQuery.of(context).size.height * 0.60,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column( // column
mainAxisAlignment: MainAxisAlignment.center, // center
children: [
Container( // if you don't have this container, there is an error
height: MediaQuery.of(context).size.height * 0.50, // new height
width: MediaQuery.of(context).size.height * 0.50, // new width
color: Colors.green,
child: GridView.builder(
padding: const EdgeInsets.all(0.0), // delete all padding from grid
itemCount: 20, // more items to scroll
gridDelegate:
const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 4,
),
itemBuilder: (context, index) => Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
child: Center(
child: Text(
index.toString(),
)),
color: Colors.blue,
),
),
),
),
],
),
),
),
)
Enclose your Grid inside a Column to allow it to be centered, because if you don't do it I can't find another way to center it because the Grid is dynamic in height and could not be centered.
And with this, you delete the big space in the red container