WeChat applet is a fast and efficient development method, and Flutter is a powerful cross-platform development framework. Combining the two, we can easily develop a WeChat Mini Program with rich functions and good user experience. Here we will introduce how to use Flutter to develop a simple weather forecast applet, and provide corresponding code examples.
1. Preparations
Before getting started, make sure you have the Flutter SDK installed and your development environment configured. In addition, you also need to register a WeChat applet developer account and obtain the corresponding AppID.
2. Create a new Flutter project
Create a new Flutter project by running the following command in a terminal or command line:
flutter create weather_mini_program cd weather_mini_program
3. Add required dependencies
In the pubspec.yaml file, add the following dependencies:
dependencies: flutter: sdk: flutter http: ^0.13.4 fluttertoast: ^8.0.7
Then run the flutter pub get command to download and install dependencies.
4. Write the page layout
Create a new folder pages under the lib directory, and then create a new file weather_page.dart under this folder. In that file, write the following code:
import 'package:flutter/material.dart'; import 'package:http/http.dart' as http; import 'package:fluttertoast/fluttertoast.dart';
class WeatherPage extends StatefulWidget { @override _WeatherPageState createState() => _WeatherPageState(); }
class _WeatherPageState extends State<WeatherPage> { String _weatherData = '';
@override void initState() { super.initState(); fetchWeatherData(); }
Future<void> fetchWeatherData() async { final url = 'https://api.example.com/weather'; // replace with the actual weather interface address final response = await http.get(Uri.parse(url)) ;
if (response.statusCode == 200) { setState(() { _weatherData = response.body; }); } else { Fluttertoast.showToast(msg: 'Failed to get weather data'); } }
@override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('天气预报'), ), body: Center( child: _weatherData.isEmpty ? CircularProgressIndicator() : Text(_weatherData), ), ); } }
In the above code, we created a WeatherPage class, which is a stateful widget (StatefulWidget). In the initState method, we call the fetchWeatherData method to get the weather data and store it in the _weatherData variable. In the build method, the page is rendered according to the state of the weather data.
5. Create entry file
Create a new file main.dart in the lib directory and write the following code:
import 'package:flutter/material.dart'; import 'package:weather_mini_program/pages/weather_page.dart';
void main() { runApp(MyApp()); }
class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( title: 'Weather Forecast Applet', theme: ThemeData( primarySwatch: Colors.blue, ), home: WeatherPage(), ); } }
In the above code, we create a MyApp class, which inherits from StatelessWidget, and returns a MaterialApp widget in the build method, in which we specify the title and theme color of the applet, and set WeatherPage as the home page of the applet.
6. Test run
Now, you can run your applet on the emulator or on a real device with the following command
flutter run
Flutter will compile and run your applet, and display it on the emulator or real device.
7. Conclusion
In addition to developing small programs with flutter, this article introduces the effect of running a Flutter application in a small program by using the small program container FinClip to run the small program in the App developed by Flutter. This method can take advantage of Flutter's powerful cross-platform capabilities and flexible UI customization capabilities, while enjoying the lightweight and efficient user experience of applets.
By using Flutter to develop a simple weather forecast WeChat applet, we have a general understanding of the entire process and method of flutter developing applets.
Of course, this is just an introductory example. The actual project may involve more functions and complex business logic. We still need to study and research in depth.