Flutter - Layout a Grid

Use whichever suits your need.

1. GridView.count(...)

   GridView.count(
     crossAxisCount: 2,
     children: <Widget>[
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
     ],
   )
   

2. GridView.builder(...)

   GridView.builder(
     gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
     itemBuilder: (_, index) => FlutterLogo(),
     itemCount: 4,
   )
   

3. GridView(...)

   GridView(
     gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
     children: <Widget>[
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
     ],
   )
   

4. GridView.custom(...)

   GridView.custom(
     gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
     childrenDelegate: SliverChildListDelegate(
       [
         FlutterLogo(),
         FlutterLogo(),
         FlutterLogo(),
         FlutterLogo(),
       ],
     ),
   )
   

5. GridView.extent(...)

   GridView.extent(
     maxCrossAxisExtent: 400,
     children: <Widget>[
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
       FlutterLogo(),
     ],
   )
   

Output (same for all):

A simple example loading images into the tiles.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(

      color: Colors.white30,
      child: GridView.count(
          crossAxisCount: 4,
          childAspectRatio: 1.0,
          padding: const EdgeInsets.all(4.0),
          mainAxisSpacing: 4.0,
          crossAxisSpacing: 4.0,
          children: <String>[
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
            'http://www.for-example.org/img/main/forexamplelogo.png',
          ].map((String url) {
            return GridTile(
                child: Image.network(url, fit: BoxFit.cover));
          }).toList()),
    );
  }
}

The Flutter Gallery app contains a real world example, which can be found here.

GridView is used for implementing material grid lists. If you know you have a fixed number of items and it's not very many (16 is fine), you can use GridView.count. However, you should note that a GridView is scrollable, and if that isn't what you want, you may be better off with just rows and columns.

import 'dart:collection';
import 'package:flutter/scheduler.dart';
import 'package:flutter/material.dart';
import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter/foundation.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.orange,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget{
  @override
  Widget build(BuildContext context){
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Grid Demo'),
      ),
      body: new GridView.count(
        crossAxisCount: 4,
        children: new List<Widget>.generate(16, (index) {
          return new GridTile(
            child: new Card(
              color: Colors.blue.shade200,
              child: new Center(
                child: new Text('tile $index'),
              )
            ),
          );
        }),
      ),
    );
  }
}