Flutter网络请求注解插件retrofit_method_annotation的使用

Flutter网络请求注解插件retrofit_method_annotation的使用

在本教程中，我们将学习如何使用retrofit_method_annotation插件来简化Flutter中的网络请求。retrofit_method_annotation插件可以帮助我们更方便地定义和处理HTTP请求。

示例代码

以下是一个完整的示例，展示了如何使用retrofit_method_annotation插件来创建一个简单的网络请求。

// example/retrofit_method_annotation_example.dart

import 'package:flutter/material.dart';
import 'package:retrofit_method_annotation/retrofit_method_annotation.dart';
import 'package:http/http.dart' as http;

// 定义API接口
[@RestApi](/user/RestApi)(baseUrl: "https://jsonplaceholder.typicode.com")
abstract class ClientService {
  factory ClientService(http.Client client) = _ClientService;

  // 定义GET请求
  @GET("/todos/{id}")
  Future<Todo> getTodo(@Path("id") int id);

  // 定义POST请求
  @POST("/todos")
  Future<Todo> createTodo(@Body() Todo todo);
}

// 定义数据模型
class Todo {
  final int userId;
  final int id;
  final String title;
  final bool completed;

  Todo({this.userId, this.id, this.title, this.completed});

  factory Todo.fromJson(Map<String, dynamic> json) {
    return Todo(
      userId: json['userId'],
      id: json['id'],
      title: json['title'],
      completed: json['completed'],
    );
  }

  Map<String, dynamic> toJson() => {
        'userId': userId,
        'id': id,
        'title': title,
        'completed': completed,
      };
}

void main() async {
  final client = http.Client();
  final service = ClientService(client);

  // 测试GET请求
  final todo = await service.getTodo(1);
  print(todo.title);

  // 测试POST请求
  final newTodo = Todo(userId: 1, title: "New Todo", completed: false);
  final createdTodo = await service.createTodo(newTodo);
  print(createdTodo.title);
}

代码解释

1. 导入必要的库:

   import 'package:flutter/material.dart';
   import 'package:retrofit_method_annotation/retrofit_method_annotation.dart';
   import 'package:http/http.dart' as http;
   

2. 定义API接口:

   [@RestApi](/user/RestApi)(baseUrl: "https://jsonplaceholder.typicode.com")
   abstract class ClientService {
     factory ClientService(http.Client client) = _ClientService;
   
     @GET("/todos/{id}")
     Future<Todo> getTodo(@Path("id") int id);
   
     @POST("/todos")
     Future<Todo> createTodo(@Body() Todo todo);
   }
   

   使用[@RestApi](/user/RestApi)注解定义了API的基本URL。@GET和@POST注解分别用于定义GET和POST请求。@Path和@Body注解用于指定路径参数和请求体。

3. 定义数据模型:

   class Todo {
     final int userId;
     final int id;
     final String title;
     final bool completed;
   
     Todo({this.userId, this.id, this.title, this.completed});
   
     factory Todo.fromJson(Map<String, dynamic> json) {
       return Todo(
         userId: json['userId'],
         id: json['id'],
         title: json['title'],
         completed: json['completed'],
       );
     }
   
     Map<String, dynamic> toJson() => {
           'userId': userId,
           'id': id,
           'title': title,
           'completed': completed,
         };
   }
   

   定义了一个Todo类，用于表示从服务器获取的数据模型。

4. 测试网络请求:

   void main() async {
     final client = http.Client();
     final service = ClientService(client);
   
     // 测试GET请求
     final todo = await service.getTodo(1);
     print(todo.title);
   
     // 测试POST请求
     final newTodo = Todo(userId: 1, title: "New Todo", completed: false);
     final createdTodo = await service.createTodo(newTodo);
     print(createdTodo.title);
   }