Image(image: NetworkImage('https://....'))
Image.network('https://...')
Image.asset('assets/images/filename')

pubspec.yaml

flutter:
  uses-material-design: true
  assets:
    - assets/images/nature.jpg

main.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Image Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Image Demo'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: ListView(

          children: <Widget>[
            Image(
              image: NetworkImage('https://images.unsplash.com/photo-1715329499438-90d5632dbcf3?w=600&auto=format&fit=crop&q=60&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxlZGl0b3JpYWwtZmVlZHwzMHx8fGVufDB8fHx8fA%3D%3D'),
            ),
            Image.network('https://flutter.github.io/assets-for-api-docs/assets/widgets/owl-2.jpg'),
            Image.asset('assets/images/nature.jpg')
          ],
        ),
      ),
    );
  }
}

Images in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

Key characteristics of Snackbars:

• Transient: They stay visible for a short duration (typically 5–10 seconds) and then disappear automatically.
• Informative: They display a concise message to the user, often accompanied by an icon for better clarity.
• Optional Action: You can optionally include an action button that the user can tap to perform a related action.

Use Cases for Snackbars:

• Success/Error Messages: Notify users about the outcome of an action (e.g., “Item added to cart!” or “Login failed”).
• Undo Actions: Provide an option to undo a recent action (e.g., “Item deleted. Undo?”).
• Background Tasks: Inform users about ongoing background processes (e.g., “Image uploading…”).

Simple Snackbar Example:

Here’s an example of a Snackbar displayed after a button press:

ElevatedButton(
  onPressed: () {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text('Item added to cart!'),
        action: SnackBarAction(
          label: 'Undo',
          onPressed: () {
            // Code to undo the action (optional)
            print('Undoing item addition');
          },
        ),
      ),
    );
  },
  child: Text('Add to Cart'),
),

SnackBar in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

Key Points about Columns

• Vertical Arrangement: Children are stacked on top of each other, with the first child at the top.
• Multiple Children: A Column can hold multiple child widgets. These child widgets can be anything from Text and Icons to other Rows or even more Columns for nested layouts.
• Customization: You can control how the children are positioned within the Column using properties like mainAxisAlignment and crossAxisAlignment.
• No Scrolling: By default, a Column doesn’t provide scrolling functionality. If you have more content than can fit on the screen, you’ll need to use a widget like ListView for scrollable content.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Column(
        children: [

          Text('Column Demo', style: TextStyle(fontSize: 30),),
          Container(
            height: 100,
            color: Colors.blue,
            margin: EdgeInsets.all(5),
          ),
          Container(
            height: 100,
            color: Colors.yellow,
            margin: EdgeInsets.all(5),
          ),
          Container(
            height: 100,
            color: Colors.green,
            margin: EdgeInsets.all(5),
          ),

        ],
      )
    );
  }

}

Column widget in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

What is SQLite?

SQLite is a lightweight relational database management system (RDBMS) that’s embedded within the application.

Why Use SQLite in Flutter?

Here are some key benefits of using SQLite with Flutter:

• Lightweight and Fast: SQLite boasts a small footprint and efficient performance, perfect for mobile apps where resources are limited.
• Serverless and Easy to Use: There’s no need to set up or manage a separate server. SQLite integrates seamlessly into your Flutter project.
• Cross-Platform Compatibility: SQLite works across Android, iOS, and even web platforms where Flutter is applicable.

Getting Started with SQLite in Flutter

To leverage SQLite in your Flutter applications, you’ll utilize the popular sqflite package. This package provides a Dart API for interacting with the SQLite database. It offers functionalities for:

• Creating and opening databases
• Defining tables and columns
• Performing CRUD operations (Create, Read, Update, Delete) on data
• Querying the database to retrieve specific information

Step#1: Adding dependencies

In order to use SQLite in Flutter we need two dependencies i.e. sqflite and path. Add these dependencies in the pubspec.yaml file.

dependencies:
  sqflite: ^2.3.3
  path: ^1.9.0

Step#2: Create database_service.dart in lib/services directory

After adding dependencies we will create a Database Service in database_service.dart. The Database Service will provide the following services:

Create database

Create tables

Add/insert data in tables

Retrieve data from tables

Update data in tables

Delete data from tables

import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';
import 'package:sqflite/sqlite_api.dart';

class DatabaseService {
  static Database? db;

  Future<Database> getDatabase() async {
    final dbDirPath = await getDatabasesPath();
    final dbPath = join(dbDirPath, "student_db.db");
    final database = await openDatabase(
        dbPath,
        onCreate: (db, version) {
          db.execute('''
            CREATE TABLE students(reg_no TEXT, name TEXT NOT NULL, cell_no TEXT) 
          ''');
        },
        version: 1
    );
    return database;
  }

  Future<Database> getDB() async {
    if (db != null ) return db!;
    db = await getDatabase();
    return db!;
  }

  Future<void> addStudent(String reg_no, String name, cell_no) async {
    final db = await getDB();

      await db.insert(
        "students",
        { "reg_no": reg_no,
          "name": name,
          "cell_no": cell_no
        }
    );
  }

  Future<List<Map>> getStudents() async {
    final db = await getDB();
    final data = await db.query("students");
    for(var d in data) {
      print(d);
    }
    return data;
  }
}

Step-3: User interface for using Database Service (Adding and retrieving data from the SQLite database)

main.dart

import 'package:flutter/material.dart';
import 'package:sqlite_demo/services/database_service.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final databaseService = DatabaseService();
  String? reg_no, name, cell_no;
  TextEditingController tcRegNo = TextEditingController();
  TextEditingController tcName = TextEditingController();
  TextEditingController tcCellNo = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          TextField(
            decoration: InputDecoration(hintText: "Reg. No."),
            controller: tcRegNo,
          ),
          TextField(
            decoration: InputDecoration(hintText: "Name"),
            controller: tcName,
          ),
          TextField(
            decoration: InputDecoration(hintText: "Cell No"),
            controller: tcCellNo,
          ),
          ElevatedButton(onPressed: addRecord, child: Text("Save")),
          ElevatedButton(onPressed: printData, child: Text("Print Data")),
         
        ]
            ),


    );

  }

void addRecord() async {
    await databaseService.addStudent(tcRegNo.text, tcName.text, tcCellNo.text);
  }

void printData() async {
  await databaseService.getStudents();
}

Widget StudentsList() {
    Future<List<Map<String, dynamic>>>? students;
    students = dbService.getStudents();
    return FutureBuilder<List<Map<String, dynamic>>>(
      future: students,
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return ListView.builder(
            itemCount: snapshot.data!.length,
            itemBuilder: (context, index) {
              final student = snapshot.data![index];
              return ListTile(
                title: Text(student['name']),
                subtitle: Text('Reg No: ${student['reg_no']}, Cell No: ${student['cell_no']}'),
              );
            },
          );
        } else if (snapshot.hasError) {
          return Center(child: Text('Error: ${snapshot.error}'));
        }
        return Center(child: CircularProgressIndicator());
      },
    );
  }

 
}

In the second video I will explain how to retrieve records from SQLite database table and display it in ListView in Flutter.

Storing Data in SQLite database in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

import '/pages/home.dart';
import '/pages/settings.dart';
import '/pages/about.dart';

import 'package:flutter/material.dart';
void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {

    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Mobile App Development'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  final List pages = [HomePage(), AboutPage(), SettingsPage() ];
  int selectedPage = 0;

  void navChanged(int index) {

    setState(() {
      selectedPage= index;
    });
  }
  @override
  Widget build(BuildContext context)  {
    return Scaffold(
        body:  pages[selectedPage],
        bottomNavigationBar: BottomNavigationBar(
          onTap: navChanged,
          items: [
            // home
            BottomNavigationBarItem(
                icon: Icon(Icons.home),
                label: "Home"
            ),

            // Profile
            BottomNavigationBarItem(
                icon: Icon(Icons.person),
                label: "Profile"
            ),

            // Settings
            BottomNavigationBarItem(
                icon: Icon(Icons.settings),
                label: "Settrings"
            ),
          ],
        ),
    );
  }
}

home.dart

import 'package:flutter/material.dart';

class HomePage extends StatelessWidget {

  @override
  Widget build(BuildContext context)  {
    return Scaffold(
        backgroundColor: Colors.green,
        body:  Center(
                child: Text("Home Page", style: TextStyle(fontSize: 30),),
                ),
        );

  }
}

about.dart

import 'package:flutter/material.dart';

class AboutPage extends StatelessWidget {

  @override
  Widget build(BuildContext context)  {
    return Scaffold(
      backgroundColor: Colors.yellow,
      body:  Center(
        child: Text("About Page", style: TextStyle(fontSize: 30)),
      ),
    );
  }
}

settings.dart

import 'package:flutter/material.dart';

class SettingsPage extends StatelessWidget {

  @override
  Widget build(BuildContext context)  {
    return Scaffold(
      backgroundColor: Colors.cyan,
      body:  Center(
        child: Text("Settings Page", style: TextStyle(fontSize: 30)),
      ),
    );

  }
}

BottomNavigationBar in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

To start navigating between pages, you use the Navigator.push, pushNamed, and pop methods.

Example

main.dart

import 'package:flutter/material.dart';
import 'pages/home.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {

    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Mobile App Development'),
    );
  }
}

home.dart

import 'package:cs06/pages/about.dart';
import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {


  @override
  Widget build(BuildContext context)  {
    return Scaffold(
        appBar: AppBar(
          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
          title: Text(widget.title),
        ),
        body:  Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(child: Text("Navigation Demo", 
                                    style: TextStyle(fontSize: 30),),),
              Container(child: Text("Main Screen"),),
              SizedBox(height: 20,),
              ElevatedButton(onPressed: aboutScreen, child: Text("About"))
            ],
          ),
        )
    );
  }
  
  void aboutScreen() {
    Navigator.push(
      context,
      MaterialPageRoute(builder: (context) => const 
                        AboutPage(title: "About me!")),
    );
  }
}

about.dart

import 'package:flutter/material.dart';

class AboutPage extends StatefulWidget {
  const AboutPage({super.key, required this.title});
  final String title;

  @override
  State<AboutPage> createState() => _AboutPageState();
}

class _AboutPageState extends State<AboutPage> {


  @override
  Widget build(BuildContext context)  {
    return Scaffold(
        appBar: AppBar(
          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
          title: Text(widget.title),
        ),
        body:  Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(child: Text("About Screen"),),
              SizedBox(height: 20,),
              ElevatedButton(onPressed: gotoHome, 
                      child: Text("Back to main!"))
            ],
          ),
        )
    );
  }

  void gotoHome() {
    Navigator.pop(context);
  }
}

Navigation in Flutter was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

Different developers may use different approach for saving files and folders. In this article I will show you how I organize my files and folders in my Flutter project.

Create the following directories/folders in your project directory:

assets/images

assets/fonts

lib/pages

lib/services

lib/models

lib/utils

lib/widgets

These folders will hold the resources as follows:

assets/images: images

assets/fonts: fonts.

lib/pages: User interface (UI) files

lib/models: Classes for data

lib/utils: Helper classes such as date calculations and data conversion

lib/widgets: User defined widgets

lib/services: Helps retrieve data from services over the Internet

The main.dart

// main.dart

import 'package:flutter/material.dart';
import 'pages/home.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {

    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Mobile App Development'),
    );
  }
}

lib/pages/home.dart

// lib/pages/home.dart

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {


  @override
  Widget build(BuildContext context)  {
    return Scaffold(
        appBar: AppBar(
          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
          title: Text(widget.title),
        ),
        body:  Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(child: Text("Hello World!"),),
            ],
          ),
        )
    );
  }
}

Organizing files and folders in Flutter project was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.

Check complete course on Udemy.

Flutter GestureDetector was originally published in Complete Flutter Guide on Medium, where people are continuing the conversation by highlighting and responding to this story.