如何测试我的远程套接字NSStream是否正确打开 [英] How to test if my remote socket NSStream are correctly open

问题描述

TL; DR：在调用 NSStream.getStreamsToHostWithName（...）？

我的应用程序是移动IOS8 swift应用程序。

My application is a mobile IOS8 swift application.

I我正在使用NSStream与远程服务器进行输入和输出套接字通信。

I am using NSStream for input and output socket communication with a remote server.

要连接到我的服务器并打开我的流，我使用以下代码：

To connect to my server and open my stream I use this code:

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。

My problem is located at //PROBLEM1 and //PROBLEM2.

在这些点上，我尝试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，那么读写操作失败。
我希望能够确定连接是否失败。

At these points I try to determine if my sockets are opened correctly, but even if the server is not running this code still works, then the read and write operations are failing. I would like to be able to determine if the connection failed or not.

也许我做错了，我不知道如何测试这个。

Maybe I am doing it totally wrong, I don't get how to test this.

推荐答案

首先，你必须在runloop上安排流 ：

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

而且，在你的代码中，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：

And, in your code, it's too soon to check the error. Because open() is async operation, you have to wait the result using delegate. Here is working example:

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)

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