NetworkManager

import SwiftUI
import Alamofire
//http://localhost:8080/PostListData_recommend_1.json
private let NetworlAPIBaseURL = "http://localhost:8080/"

typealias NetworkRequestResult = Result<Data,Error>
typealias NetworkRequestCompletion = (NetworkRequestResult) -> Void
class  NetworkManager{
    static let shared = NetworkManager()
    var commonHeaders: HTTPHeaders {
        ["user_id": "123","token": "XXXXXX"]
    }
    private init(){}
    @discardableResult
    func fetchingGet(
        path: String,
        params: Parameters?,
        completionCallBack: @escaping NetworkRequestCompletion)
    -> DataRequest {
        Alamofire.AF.request(NetworlAPIBaseURL + path,
                   parameters: params,
                   headers: commonHeaders,
                   requestModifier: {$0.timeoutInterval = 15})
            .responseData { response in
                switch response.result {
                case let .success(data):
                    completionCallBack(.success(data))
                    break
                case let .failure(error):
                    completionCallBack(self.handleError(error))
                    break
                    
                }
                
            }
    }
    
    
    @discardableResult
    func fetchingPost(
        path: String,
        params: Parameters?,
        completionCallBack: @escaping NetworkRequestCompletion)-> DataRequest {
            Alamofire.AF.request(NetworlAPIBaseURL + path, method: .post,parameters: params,encoding: JSONEncoding.prettyPrinted,headers: commonHeaders,requestModifier: {$0.timeoutInterval = 15})
                .responseData { response in
                    switch response.result {
                    case let .success(data):
                        completionCallBack(.success(data))
                        break
                    case let .failure(error):
                        completionCallBack(self.handleError(error))
                        break
                        
                    }
                    
                }
        }
    
    private func handleError(_ error: AFError) -> NetworkRequestResult {
        if let underlyingError = error.underlyingError {
            let nserror = underlyingError as NSError
            let code = nserror.code
            if  code == NSURLErrorNotConnectedToInternet ||
                code == NSURLErrorTimedOut ||
                code == NSURLErrorInternationalRoamingOff ||
                code == NSURLErrorDataNotAllowed ||
                code == NSURLErrorCannotFindHost ||
                code == NSURLErrorCannotConnectToHost ||
                code == NSURLErrorNetworkConnectionLost {
                var userInfo = nserror.userInfo
                userInfo[NSLocalizedDescriptionKey] = "网络连接有问题喔～"
                let currentError = NSError(domain: nserror.domain, code: code, userInfo: userInfo)
                return .failure(currentError)
            }
        }
        return .failure(error)
    }
    
}

NetworkAPI

import SwiftUI

class NetwokAPI {
    static func  recommendPostList(completion: @escaping (Result<PostList,Error>)->Void){
        NetworkManager.shared.fetchingGet(path: "PostListData_recommend_1.json", params: nil) { result in
            switch result {
            case let .success(data):
                let parseResult: Result<PostList,Error> =  self.parseDate(data)
                
                completion(parseResult)
                
            case let .failure(error):
                completion(.failure(error))
            }
        }
        
    }
    
    static func createPost(text: String,completion: @escaping (Result<Post,Error>)-> Void) {
        NetworkManager.shared.fetchingPost(path: "createPost", params: ["text": text]) { result in
            switch result {
            case let .success(data):
                let parseResult: Result<Post,Error> = self.parseDate(data)
                completion(parseResult)
            case let .failure(error):
                completion(.failure(error))
                
            }
        }
        
    }
    
    
    static func  hotPostList(completion: @escaping (Result<PostList,Error>)->Void){
        NetworkManager.shared.fetchingGet(path: "PostListData_hot_1.json", params: nil) { result in
            switch result {
            case let .success(data):
                let result: Result<PostList,Error> = self.parseDate(data)
                
                completion(result)
                
            case let .failure(error):
                completion(.failure(error))
            }
        }
        
    }
    
    private static func parseDate<T: Decodable>(_ data: Data)-> Result<T,Error> {
        guard let decodeData = try? JSONDecoder().decode(T.self, from: data)else {
            let error = NSError(domain: "NetworkAPIError", code: 0, userInfo:  [NSLocalizedDescriptionKey: "Can not parse data"])
            return .failure(error)
        }
        return .success(decodeData)
    }
    
}

模型

import Foundation

struct PostList: Codable {
    var list: [Post]
}

struct Post: Codable, Identifiable {
    let id: Int
    let avatar: String // image name
    let vip: Bool
    let name: String
    let date: String // yyyy-MM-dd HH:mm:ss
    
    var isFollowed: Bool
    
    let text: String
    let images: [String] // image names
    
    var commentCount: Int
    var likeCount: Int
    var isLiked: Bool
}

调用

import SwiftUI
import Alamofire
struct ContentView3: View {
    @State private var text = ""
    var body: some View {
        VStack {
            Text(text).font(.title)
            Button(action: {
                self.startLoad()
            }) {
                Text("Start").font(.largeTitle)
                    .foregroundColor(.yellow)
            }
            Button(action: {
                self.text = ""
            }) {
                Text("Clear").font(.largeTitle)
            }
        }
    }
    func startLoad() {
        NetwokAPI.hotPostList { result in
            switch result {
            case let .success(list):
                self.updateText("Post count \(list.list.count)")
            case let .failure(error):
                self.updateText(error.localizedDescription)
            }
        }
    }
    func updateText(_ text: String) {
       self.text = text
     }
}