Swift_网络请求

一、网络请求步骤

1. 设置请求url
2. 设置URLRequest对象，配置请求相关信息
3. 创建会话配置URLSessionConfiguration
4. 创建会话URLSession
5. 创建任务和设置请求回调，并发起请求

_{一般通过以上几个步来完成网络请求，当然要根据不同应用场景来配置请求属性。}

二、使用

1、原生

json转dic

    //json转dic
    func getDictionaryFromJSONString(jsonString:String) ->NSDictionary{
        let jsonData:Data = jsonString.data(using: .utf8)!
        let dict = try? JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers)
        if dict != nil {
            return dict as! NSDictionary
        }
        return NSDictionary()
    }

Get

    func makeLogon() {
        // 构建URL
        let url:URL = URL(string: "https://xxx/xxx/API?xxx")!
        // 发送HTTP请求的的session对象
        let session = URLSession.shared
        // 构建请求request
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        // 发一个get请求
        let task = session.dataTask(with: request as URLRequest) {(
            data, response, error) in
            
            guard let data = data, let _:URLResponse = response, error == nil else {
                print("error")
                return
            }
            let dataString =  String(data: data, encoding: String.Encoding.utf8)
            let dict = self.getDictionaryFromJSONString(jsonString: dataString!)
            print(dict)
        }
        task.resume()
    }

Post

    func makeUpdateCountSheet() {
        // 这里直接使用 jsonString 转成字典，然后转成 Data，将 流 放到 request的 httpBody中， 模拟发送一个http请求
        let jsonString = "{\"Data\":{\"xxx\":\"834\",\"xxx\":[{\"xxx\":[{\"xxx\":\"031019\",\"xxx\":\"ADD\",\"xxx\":\"9\"},{\"xxx\":\"5651G-06920ADBAA\",\"xxx\":\"ADD\",\"xxx\":\"6\"}],\"xxx\":\"xxx\",\"Counted\":true,\"xxx\":true,\"LineNum\":\"1\",\"xxx\":\"235\",\"Quantity\":\"15\"}],\"xxx\":\"\",\"Initials\":\"we\",\"xxx\":true},\"xxx\":\"\"}"
        let dict = self.getDictionaryFromJSONString(jsonString: jsonString)
        print(dict)
        var  jsonData = NSData()
        do {
             jsonData = try JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted) as NSData
        } catch {
            print(error.localizedDescription)
        }
        // 构建URL
        let url:URL = URL(string: "https://xxx/xxx/API?xxx")!
        // session
        let session = URLSession.shared
        // request
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        // 设置Content-Length，非必须
        request.setValue("\(jsonData.length)", forHTTPHeaderField: "Content-Length")
        // 设置 Content-Type 为 json 类型
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        // POST    请求将 数据 放置到 请求体中
        request.httpBody = jsonData as Data
        // 发送请求
        let task = session.dataTask(with: request as URLRequest) {(
            data, response, error) in

            guard let data = data, let _:URLResponse = response, error == nil else {
                print("error")
                return
            }
            // 返回值 utf8 转码
            let dataString =  String(data: data, encoding: String.Encoding.utf8)
            // 将 jsonString 转成字典
            let dict = self.getDictionaryFromJSONString(jsonString: dataString!)
            print(dict)
        }
        task.resume()
    }

2、Alamofire 

3、Moya+Alamofire 

Moya是一个对Alamofire封装的库，提供简洁的接口供开发者调用，抽象了URL和Parameters来帮助使用者生成urlRequest，最后通过alamofire发起请求。
具体使用时在Moya和Your App之间加一层Rx，用于处理请求回来的数据