GridView does not cover background if totalWidth is not dividable by crossAxisCount

Question

I created a GridView with crossAxisCount: 3. The problem is that if the totalWidth of the GridView is not dividable by 3, the background will shine through the GridView resulting in like the background colored lines visible on the GridView. Is there a way to avoid it?

Note: Problem does not appear on mobile

Code for Reproduction:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SizedBox(
          width: 301,
          child: GridView.count(
            crossAxisCount: 3,
            children: [
              for (int i = 0; i < 12; i++)
                Container(
                  color: Colors.black,
                ),
            ],
          ),
        ),
      ),
    );
  }
}

Answer 1

This can be removed using border.

Container(
  decoration: BoxDecoration(
    color: Colors.black,
    border: Border.all(
      color: Colors.black,
    ),
  ),
),

Answer 2

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key}) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    var responsive = MediaQuery.of(context).size; // add this line
    return Scaffold(
      body: SizedBox(
        width: responsive.width, // add this line
        height: responsive.height, // add this line
        child: GridView.count(
          crossAxisCount: 3,
          children: [
            for (int i = 0; i < 12; i++)
              Container( // change content to view borders og grid
                decoration: BoxDecoration( // add this line
                  border: Border.all( // add this line
                    color: Colors.white, // add this line
                    width: 1, // add this line
                  ), // add this line
                  color: Colors.black, // add this line
                ), // add this line
              ),
          ],
        ),
      ),
    );
  }
}

The result will be as this:

Answer 3

or you can just put value border width = 0.0

SizedBox(
        width: 301,
        child: GridView.count(
          crossAxisCount: 3,
          children: [
            for (int i = 0; i < 12; i++)
              Container(
                decoration: BoxDecoration(
                  color: Colors.black,
                  border: Border.all(
                    width: 0.0,
                  ),
                ),
              ),
          ],
        ),
      ),