flutter_provider_demo/lib/dao/user_dao.dart

import 'package:dio/dio.dart';
import 'package:flutter_provider_demo/model/api.dart';
import 'package:flutter_provider_demo/model/user_model.dart';

class UserDao {
  Future<UserModel> login(String username, String pwd) async {
    Map<String, dynamic> params = {"username": username, "pwd": pwd};
    Response response = await Dio().post(
      Api.login,
      data: params,
    );
    return UserModel.fromJson(response.data);
  }
}