没有握手的iOS网络套接字

Question

我想在iOS上建立一个简单的本地套接字通信。在查看了其他库后，我发现自去年以来Swift原生的websocketlib运行得很好，但附带了一个我想禁用的恶意握手(否则我将不得不调整服务器响应等(

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()

我在谷歌上搜索了nw_ws_options_set_skip_handshake，但找不到如何使用它的示例。有什么想法吗？

Answer 1

正如@SteffenUllrich所建议的，我更多地研究了TCP套接字通信，并找到了一种简单的通信方式。这里是我的解决方案，希望它能帮助其他人：

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, completion: { (data, context, isComplete, 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((来启动连接，使用sendString((来发送一些文本。接收应持续运行。我没有共享命令处理程序，但它在常规命令上重新运行receiveMsg((，在服务器启动文件传输时重新运行receive file(((init还包含在receive((函数中设置预期字节大小所需的fileSize！(。