如何测试我的远程套接字NSStream是否正确打开

Question

TL；DR：调用NSStream.getStreamsToHostWithName(...)后，如何检查我的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//PROBLEM1和//PROBLEM2。

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

也许我做得完全错了，我不知道如何测试。

Answer 1

首先，您必须在runloop:上调度流

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

而且，在您的代码中，现在检查错误还为时过早。因为open()是异步操作，所以必须使用delegate等待结果。以下是工作示例：

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：

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