Flutter Project Structure

Main directories and files

1. android Android platform code
2. ios iOS platform code
3. build produced by the build, ignore it
4. lib cross-platform code, the directory you actually care about in a Flutter project
5. test test code
6. pubspec.yaml the project manifest, equivalent to package.json in a Node.js project. It holds the project description and the libraries it depends on

The main files

pubspec.yaml

main.dart

Flutter is written in dart (later chapters will add more on dart). The image below shows the code after simplification. Three classes are enough for one app screen, and it runs on both iOS and Android at the same time. That simple. And main.dart is the entry file for every Flutter project: it cannot be deleted or renamed.