Put capital letters where they belong
The Dart language is case-sensitive. Don't typeClass when you mean to type class. Don't type Runapp when you mean to type runApp.
Use parentheses when (and only when) they're appropriate
Remember the difference between_incrementCounter with parentheses:
void <strong>_incrementCounter()</strong> {
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
)
and _incrementCounter without parentheses:
floatingActionButton: FloatingActionButton( onPressed: _incrementCounter, tooltip: 'Increment', child: Icon(Icons.add), )
Limit access to Dart variables
Wherever you can, avoid declaring top-level variables. To keep other files from changing your file's variables, start variable names with an underscore.Call setState
If you press a widget and nothing happens, look for a method with a missingsetState call.
Make adjustments for indices starting at zero
To make values start with 1, you have to add 1:return ListView.builder(
itemCount: 25,
itemBuilder: (context, index) => ListTile(
title: Text('Rocky ${index + 1}'),
onTap: () => goToDetailPage(index + 1),
),
);
Use the Expanded widget
When your test device displays black-and-yellow stripes or an empty screen, the layout you've coded is causing trouble. Consider wrapping one or more widgets inside Expanded widgets. Sometimes, it works wonders for your Flutter app.
Add itemCount to your ListView.builder
Without anitemCount parameter, the list of items never ends.
Add imports when they're required
For example, if you want to use Dart's math library, start your file withimport 'dart:math';If your Flutter app pulls data from the Internet, add this line to the top of your file:
import 'package:http/http.dart';
Declare assets and dependencies in pubspec.yaml
To displaybrokenheart.jpg and heart.jpg on the screen, add some lines to your Flutterproject's pubspec.yaml file:
assets: - brokenheart.jpeg - heart.jpegTo get data from the Internet, add
http to the file's list of dependencies:
dependencies: flutter: sdk: flutter http: ^0.12.0+4And remember, in a
pubspec.yaml file, indentation matters.
Indent your code according to Dart language guidelines
Code that's not properly indented is difficult to read and difficult to maintain. Format your code by selecting Code→Reformat Code from Android Studio's main menu.Want to learn more? Check out our Flutter Cheat Sheet.