Sockets 如何测试远程套接字NSStream是否正确打开

TL；DR：调用

NSStream.getStreamsToHostWithName（…）

后，如何检查远程流是否正确打开

我的应用程序是一个移动IOS8 swift应用程序

我使用NSStream与远程服务器进行输入和输出套接字通信

要连接到我的服务器并打开我的流，我使用以下代码：

func connect(host: String, port: Int) -> Bool
{
    //clear the previous connection if existing (and update self.connected)
    disconnect()
    //updating the current connection
    self.host = host
    self.port = port

    //pairing NSstreams with remote connection
    NSStream.getStreamsToHostWithName(self.host!, port: self.port!, inputStream: &inputStream, outputStream: &outputStream)

    if (self.inputStream != nil && self.outputStream != nil)
    {
        //open streams
        self.inputStream?.open()
        self.outputStream?.open()
    }
    if self.outputStream?.streamError == nil && self.inputStream?.streamError == nil
    {
        println("SOK")    //PROBLEM 1
    }
    //error checking after opening streams // PROBLEM 2
    if var inputStreamErr: CFError = CFReadStreamCopyError(self.inputStream)?
    {
        println("InputStream error : " + CFErrorCopyDescription(inputStreamErr))
    }
    else if var outputStreamErr: CFError = CFWriteStreamCopyError(self.outputStream)?
    {
        println("OutStream error : " + CFErrorCopyDescription(outputStreamErr))
    }
    else
    {
        //set the delegate to self
        self.inputStream?.delegate = self
        self.outputStream?.delegate = self
        self.connected = true
    }
    //return connection state
    return self.connected
}

我的问题位于//问题1和//问题2

在这些点上，我试图确定套接字是否正确打开，但即使服务器没有运行此代码，代码仍然可以工作，那么读写操作也会失败。 我希望能够确定连接是否失败

也许我做得完全不对，我不知道如何测试它。

首先，你必须：

而且，在您的代码中，检查错误还为时过早。由于

open（）

是异步操作，因此必须使用

委托等待结果。下面是一个工作示例：

import Foundation

class Connection: NSObject, NSStreamDelegate {
var host:String?
var port:Int?
var inputStream: NSInputStream?
var outputStream: NSOutputStream?

func connect(host: String, port: Int) {

    self.host = host
    self.port = port

    NSStream.getStreamsToHostWithName(host, port: port, inputStream: &inputStream, outputStream: &outputStream)

    if inputStream != nil && outputStream != nil {

        // Set delegate
        inputStream!.delegate = self
        outputStream!.delegate = self

        // Schedule
        inputStream!.scheduleInRunLoop(.mainRunLoop(), forMode: NSDefaultRunLoopMode)
        outputStream!.scheduleInRunLoop(.mainRunLoop(), forMode: NSDefaultRunLoopMode)

        print("Start open()")

        // Open!
        inputStream!.open()
        outputStream!.open()
    }
}

func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
    if aStream === inputStream {
        switch eventCode {
        case NSStreamEvent.ErrorOccurred:
            print("input: ErrorOccurred: \(aStream.streamError?.description)")
        case NSStreamEvent.OpenCompleted:
            print("input: OpenCompleted")
        case NSStreamEvent.HasBytesAvailable:
            print("input: HasBytesAvailable")

            // Here you can `read()` from `inputStream`

        default:
            break
        }
    }
    else if aStream === outputStream {
        switch eventCode {
        case NSStreamEvent.ErrorOccurred:
            print("output: ErrorOccurred: \(aStream.streamError?.description)")
        case NSStreamEvent.OpenCompleted:
            print("output: OpenCompleted")
        case NSStreamEvent.HasSpaceAvailable:
            print("output: HasSpaceAvailable")

            // Here you can write() to `outputStream`

        default:
            break
        }
    }
}

}

然后：

谢谢你的准确回答。我只是有些问题。首先，执行调度部分是否使我的流异步？我希望我的操作是同步的。据我所知，流本身总是非阻塞的。如果需要同步操作，则必须在true{…}

循环时使用轮询。请看：我认为流是阻塞的，NSInputStream.read（）操作是被默认值阻塞的。不管怎样，我用你的答案重塑了我的整个类。我正在启动swift，它让我掌握了swift中的代理、事件处理和runloop。谢谢！我要在哪里写这两行？输入流！。scheduleInRunLoop（.mainRunLoop（），forMode:NSDefaultRunLoopMode）outputStream！。scheduleInRunLoop（.mainRunLoop（），forMode:NSDefaultRunLoopMode）

import Foundation

class Connection: NSObject, NSStreamDelegate {
var host:String?
var port:Int?
var inputStream: NSInputStream?
var outputStream: NSOutputStream?

func connect(host: String, port: Int) {

    self.host = host
    self.port = port

    NSStream.getStreamsToHostWithName(host, port: port, inputStream: &inputStream, outputStream: &outputStream)

    if inputStream != nil && outputStream != nil {

        // Set delegate
        inputStream!.delegate = self
        outputStream!.delegate = self

        // Schedule
        inputStream!.scheduleInRunLoop(.mainRunLoop(), forMode: NSDefaultRunLoopMode)
        outputStream!.scheduleInRunLoop(.mainRunLoop(), forMode: NSDefaultRunLoopMode)

        print("Start open()")

        // Open!
        inputStream!.open()
        outputStream!.open()
    }
}

func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
    if aStream === inputStream {
        switch eventCode {
        case NSStreamEvent.ErrorOccurred:
            print("input: ErrorOccurred: \(aStream.streamError?.description)")
        case NSStreamEvent.OpenCompleted:
            print("input: OpenCompleted")
        case NSStreamEvent.HasBytesAvailable:
            print("input: HasBytesAvailable")

            // Here you can `read()` from `inputStream`

        default:
            break
        }
    }
    else if aStream === outputStream {
        switch eventCode {
        case NSStreamEvent.ErrorOccurred:
            print("output: ErrorOccurred: \(aStream.streamError?.description)")
        case NSStreamEvent.OpenCompleted:
            print("output: OpenCompleted")
        case NSStreamEvent.HasSpaceAvailable:
            print("output: HasSpaceAvailable")

            // Here you can write() to `outputStream`

        default:
            break
        }
    }
}

}

let conn = Connection()
conn.connect("www.example.com", port: 80)