1.在viewcotroller中写入方法

func getAFNetWorkingJsonData(channel:String) -> Void {

        var urlString = "http://api.jisuapi.com/news/get?channel=\(channel)&start=0&num=10&appkey=de394933e1a3e2db"

        urlString = urlString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlFragmentAllowed)!

        NetworkTools.shareInstance.request(methodType: .GET, urlString: urlString, parameters: ["":"" as AnyObject]) { (jsonData, error) in

            if error != nil  {

                print(error!)

                return

            }

            print(jsonData!)

        }

2.创建一个类封装

// 定义枚举类型

enum HTTPRequestType : Int{

    case GET = 0

    case POST

}

class NetworkTools: AFHTTPSessionManager {

    // 设计单例 let是线程安全的

    static let shareInstance : NetworkTools = {

        let tools = NetworkTools()

        tools.responseSerializer.acceptableContentTypes?.insert("text/html")

        return tools

    }()

}

// 封装请求方法

extension NetworkTools {

    func request(methodType : HTTPRequestType, urlString : String, parameters : [String : AnyObject], finished :@escaping (_ result : AnyObject?, _ error : Error?)-> ())  {

        // 1 成功回调

        let successCallBack = {(task :URLSessionDataTask, result : Any) in

            finished(result as AnyObject?, nil)

        }

        // 2 失败回调

        let failureCallBack = {(task : URLSessionDataTask?, error :Error) in

            finished(nil, error)

        }

        if methodType == .GET {

            // get请求

            get(urlString, parameters: parameters, progress: nil, success: successCallBack, failure: failureCallBack)

        }else {

            // post请求

            post(urlString, parameters: parameters, progress: nil, success: successCallBack, failure: failureCallBack)

        }

    }

}