Custom Height for Widget in GridView

 import 'package:flutter/material.dart';

 void main() {
   runApp(HomeScreen());
 }

 class HomeScreen extends StatefulWidget {
   @override
   _RunMyAppState createState() => _RunMyAppState();
 }

 class _RunMyAppState extends State<HomeScreen> {
   List<String> widgetList = ['One', 'Two', 'Three','Four'];
   @override
   Widget build(BuildContext context) {
     //Size of grid view 
     var size = MediaQuery.of(context).size;
     //Height of grid view
     final double itemHeight = (size.height - kToolbarHeight - 24) / 2;
     //width of grid view
     final double itemWidth = size.width / 2;
     return Scaffold(
       appBar: AppBar(
         title: Text("Candidroot solutions"),
       ),
       body: Container(
         child: GridView.count(
           crossAxisCount: 2,
           childAspectRatio: (itemWidth / itemHeight),
           controller: ScrollController(keepScrollOffset: false),
           shrinkWrap: true,
           scrollDirection: Axis.vertical,
           children: widgetList.map((String value) {
             return Container(
               color: Colors.blue,
               margin: EdgeInsets.all(1.0),
               child: Center(
                 child: Text(
                  value,
                  style: TextStyle(
                    fontSize: 30.0,
                      color: Colors.white
                   ),
                 ),
               ),
             );
           }).toList(),
         ),
       ),
     );
    }
  }