没有握手的iOS网络套接字

问题描述

我想在iOS上建立一个简单的本地Socket通信。在研究了其他库之后，我发现自去年以来，Swift原生提供的websocket库运行良好，但是带有一个我想禁用的讨厌的握手（否则，我将不得不调整服务器响应等）。我的代码如下：

let webSocketDelegate = WebSocket()
                let session = URLSession(configuration: .default,delegate: webSocketDelegate,delegateQueue: OperationQueue())
                let url = URL(string: "ws://192.168.43.1:6000")!
                let webSocketTask = session.webSocketTask(with: url)
                func send() {
                    dispatchQueue.global().asyncAfter(deadline: .Now() + 1) {
                        send()
                        webSocketTask.send(.string("New Message")) { error in
                          if let error = error {
                            print("Error when sending a message \(error)")
                          }
                        }
                    }
                }

             
                webSocketTask.receive { result in
                  switch result {
                  case .success(let message):
                    switch message {
                    case .data(let data):
                      print("Data received \(data)")
                    case .string(let text):
                      print("Text received \(text)")
                    }
                  case .failure(let error):
                    print("Error when receiving \(error)")
                  }
                  
                }
                
                webSocketTask.resume()

我用Google搜索并找到了nw_ws_options_set_skip_handshake，但找不到如何使用它的示例。有什么想法吗？

解决方法

正如@SteffenUllrich所建议的，我对TCP套接字通信进行了更多研究，并找到了一种简单的通信方式。这是我的解决方案，希望对您有所帮助。

 let queue = DispatchQueue(label: "TCP Client Queue")
        let connection = NWConnection(to: NWEndpoint.hostPort(host: "192.168.99.1",port: 7000),using: NWParameters.init(tls: nil))
           
        func connect() {
            
            connection.stateUpdateHandler = { (newState) in
                switch (newState) {
                case .ready:
                    print("Socket: ready")
                    sendString(text: "Hello server!")
                    receiveMsg()
                default: print("Socket: \(newState)")
                }
            }
            connection.start(queue: queue)
            }
            
        func receiveMsg() {
            connection.receive(minimumIncompleteLength: 1,maximumLength: 1000,completion: { (data,context,isComplete,error) in
                if((data) != nil){
                    let text:String = String(decoding: data!,as: UTF8.self)
                    //send string to handler function,trim linebreak for single line commands
                    handleMsg(msg: text.trimmingCharacters(in: .newlines))
                }
                else{receiveMsg()//go back to receiving}
            })
        }
        
        func receiveFile() {
            print("Receiving file...")
//fileSize was sent before submission 
            connection.receive(minimumIncompleteLength: Int(fileSize),maximumLength: Int(fileSize)+1000,error) in
                saveFile(data: data!)//save data to file
            })
        }
        
        func sendString(text:String) {
                let data:Data? = "\(text)\n".data(using: .utf8)//add linebreak to single line string,otherwise it does not release transmission
                connection.send(content: data,completion: NWConnection.SendCompletion.contentProcessed(({ (NWError) in
                    if (NWError == nil) {
                        print("Data was sent to TCP destination ")
                    } else {
                        print("ERROR! Error when data (Type: Data) sending. NWError: \n \(NWError!)")
                    }
                })))
            }

您只需要调用connect（）即可开始连接，使用sendString（）发送一些文本。接收应持续运行。我没有共享命令处理程序，但是它在常规命令上重新运行receiveMsg（），并在服务器启动文件传输时重新运行receiveFile（）（初始化文件还包含在文件中设置预期字节大小所需的fileSize）。 receive（）函数！）。