Flutter Mobile Development · Aula

Navegação básica entre páginas

Aprenda a empilhar e remover rotas usando Navigator, permitindo transições simples entre diferentes telas do seu aplicativo Flutter.

Navegação básica entre páginas é uma aula grátis de Flutter Mobile Development no CoddyKit. Esta é a aula 1 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de Flutter Mobile Development, e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de Flutter Mobile Development inclui 4 aulas no total.

Partes desta aula ainda não foram traduzidas e aparecem em inglês.

Navigating Your App

Think of a mobile app as a collection of pages or "screens." Navigation is how users move between these screens, like going from a product list to a product detail page.

Apps need a clear way to move forward.
Apps also need a way to go back.
Flutter provides powerful tools for this.

Meet the Navigator

In Flutter, the Navigator widget manages a stack of Route objects. When you want to show a new screen, you "push" a route onto this stack. When you want to go back, you "pop" a route off the stack.

It's like a stack of playing cards.
New cards go on top (push).
You remove cards from the top (pop).

Understanding Routes

A Route is an abstraction for a "screen" or "page" in your app. Flutter provides a common type of route called MaterialPageRoute, which creates a platform-specific transition animation (like sliding in from the right on Android).

It's the blueprint for how a new screen will look and behave when shown.

Moving Forward with push()

To navigate to a new screen, you use Navigator.push(). This method takes a BuildContext and a MaterialPageRoute as arguments.

The builder function inside MaterialPageRoute tells Flutter which widget to build for the new screen.

Try Pushing a Route

This example shows how to push a new screen when a button is pressed. Run it and tap the button!

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(
      home: HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Home Screen')),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => SecondScreen()),
            );
          },
          child: const Text('Go to Second Screen'),
        ),
      ),
    );
  }
}

class SecondScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Second Screen')),
      body: const Center(
        child: Text('You are on the second screen!'),
      ),
    );
  }
}

What is BuildContext?

You might have noticed context being passed around. BuildContext is a handle to the location of a widget in the widget tree. It helps widgets locate other widgets or data higher up in the tree.

The Navigator uses this context to know which navigation stack to operate on.

Going Back with pop()

When you want to return to the previous screen, you "pop" the current route off the navigation stack using Navigator.pop(). This will reveal the screen that was underneath.

Flutter's AppBar often provides a back button automatically when a new route is pushed, which internally calls Navigator.pop().

Try Popping a Route

Let's modify our previous example to include a button on the second screen that allows us to explicitly go back to the home screen.

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(
      home: HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Home Screen')),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => SecondScreen()),
            );
          },
          child: const Text('Go to Second Screen'),
        ),
      ),
    );
  }
}

class SecondScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Second Screen')),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            Navigator.pop(context); // This will go back!
          },
          child: const Text('Go Back'),
        ),
      ),
    );
  }
}

Visualizing the Stack

Imagine the Navigator maintains a stack of screens. When you push, a new screen is placed on top. When you pop, the top screen is removed.

The user always sees the topmost screen. This stack behavior is fundamental to how navigation works in Flutter.

Push: Adds to top.
Pop: Removes from top.
First screen is at the bottom.

Navigation Check

Consider a Flutter app with two screens, ScreenA and ScreenB. If you are currently on ScreenA and want to move to ScreenB, then later return to ScreenA, which sequence of Navigator methods would you use?

Recap: Basic Navigation

Great job! You've learned the core concepts of basic navigation in Flutter:

The Navigator manages a stack of routes.
MaterialPageRoute defines a new screen.
Navigator.push() adds a new screen to the stack.
Navigator.pop() removes the current screen from the stack.
BuildContext is essential for navigation operations.

Next, we'll explore more advanced navigation techniques like named routes!

Perguntas Frequentes

A aula “Navegação básica entre páginas” é grátis?

Sim — o texto completo de “Navegação básica entre páginas” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de Flutter Mobile Development, atualize para CoddyKit PRO. O curso de Flutter Mobile Development inclui 4 aulas no total.

O que vou aprender em “Navegação básica entre páginas”?

Aprenda a empilhar e remover rotas usando Navigator, permitindo transições simples entre diferentes telas do seu aplicativo Flutter. Você pratica Flutter Mobile Development com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.

Preciso ter experiência prévia para começar Flutter Mobile Development?

Nenhuma experiência prévia é necessária. Flutter Mobile Development no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 1 de 4.

Quanto tempo leva a aula “Navegação básica entre páginas”?

A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.

Posso escrever e executar código nesta aula de Flutter Mobile Development?

Sim. Cada aula de Flutter Mobile Development inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.

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