我之前将代码写在另一个项目中的一个类里，其方法定义如下：
class ViewController: UIViewController, NSStreamDelegate, UITextFieldDelegate {
然后我将连接移到它自己的类中，这样我就可以在每个连接中重复使用它：
class XMPPConnection: NSObject, NSStreamDelegate
当我这样做时，我把所有的
viewDidLoad()代码移到了init()中。我还尝试将init代码放在一个单独的函数中，在实例化类之后调用该函数。但是这并没有改变任何事情。我可以在两个项目之间切换，旧的和新的，只是为了确保它不是服务器的问题，这样做证实它不是。
每次运行应用程序后，结果都不同。它要么不调用
HasSpaceAvailable而只是坐在那里，要么在我的类class AppDelegate: UIResponder, UIApplicationDelegate, FBLoginViewDelegate中抛出一个(lldb)错误。虽然这个错误可能与Facebook集成有关，但是使用lldb并没有什么可看的。然而，每次运行，HasSpaceAvailable都不会被调用，就像其他项目一样。这是NSStreamDelegate的完整代码，以免引起混淆。这个类是使用XMPP协议连接的一种相当标准的方法。
import UIKit
import Foundation
class XMPPConnection: NSObject, NSStreamDelegate { //NSObject
var input : NSInputStream?
var output: NSOutputStream?
//let XMLStream: String = "<stream:stream xmlns:stream='http://etherx.jabber.org/streams' version='1.0' xmlns='jabber:client' to='mydomain.com' xml:lang='en' xmlns:xml='http://www.w3.org/XML/1998/namespace'>"
let XMLStream: String = "<stream:stream to='mydomain.com' xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' version='1.0'>"
var XMLAuth: String?
let XMLStreamEnd: String = "</stream:stream>"
let XMLResource: String = "<iq type='set' id='bind_1'><bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'><resource>OneSide</resource></bind></iq>"
let XMLSession: String = "<iq type='set' id='sess_1'><session xmlns='urn:ietf:params:xml:ns:xmpp-session'/></iq>"
let XMLStartTLS: String = "<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>";
var messagesToBeSent:[String] = []
var lastSentMessageID = 0
var lastReceivedMessageID = 0
init(facebookID: String) {
super.init()
let username = "admin@mydomain.com" //should hash device ID
let password = "123456" //hash it
var UTF8AuthStr = "\0\(username)\0\(password)".dataUsingEncoding(NSUTF8StringEncoding)
let Base64Str = UTF8AuthStr!.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.fromRaw(0)!)
XMLAuth = "<auth xmlns='urn:ietf:params:xml:ns:xmpp-sasl' mechanism='PLAIN'>\(Base64Str)</auth>"
//println(XMLAuth)
self.connectToSocket("mydomain.com", port: 5222)
send(self.XMLStream)
//send(self.XMLStartTLS)
/*send(self.XMLAuth!)
send(self.XMLStream)
send(self.XMLResource)
send(self.XMLSession)*/
//sendMessage("hi")
}
func connectToSocket(host: String, port: Int) {
NSStream.getStreamsToHostWithName(host, port: port, inputStream: &(self.input), outputStream: &(self.output))
self.input!.delegate = self
self.output!.delegate = self
self.input!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
self.output!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
self.input!.open()
self.output!.open()
println("Connected")
//let bytesWritten = self.output!.write(UnsafePointer(data.bytes), maxLength: data.length)
//println(bytesWritten)
}
//The delegate receives this message when a given event has occurred on a given stream.
func stream(theStream: NSStream!, handleEvent streamEvent: NSStreamEvent) {
println("Message received")
switch streamEvent {
case NSStreamEvent.None:
println("NSStreamEvent.None")
case NSStreamEvent.OpenCompleted:
println("NSStreamEvent.OpenCompleted")
case NSStreamEvent.HasBytesAvailable:
println("NSStreamEvent.HasBytesAvailable")
if let inputStream = theStream as? NSInputStream {
//println("is NSInputStream")
if inputStream.hasBytesAvailable {
//println("hasBytesAvailable")
let bufferSize = 1024
var buffer = Array<UInt8>(count: bufferSize, repeatedValue: 0)
var bytesRead: Int = inputStream.read(&buffer, maxLength: bufferSize)
//println(bytesRead)
if bytesRead >= 0 {
lastReceivedMessageID++
var output: String = NSString(bytes: &buffer, length: bytesRead, encoding: NSUTF8StringEncoding)
//println("output is")
println(output)
} else {
println("error")
// Handle error
}
}
}
case NSStreamEvent.HasSpaceAvailable:
println("NSStreamEvent.HasSpaceAvailable")
send(nil) //send next item
//send next message or
//what if there is no next message to send, and instead waiting user input?
case NSStreamEvent.ErrorOccurred:
println("NSStreamEvent.ErrorOccurred")
case NSStreamEvent.EndEncountered:
println("NSStreamEvent.EndEncountered")
default:
println("default")
}
}
func send(message:String?){
if (self.output!.hasSpaceAvailable){ //stream ready for input
//println("true hasSpaceAvailable")
var data:NSData
var thisMessage:String
if message == nil{ // no message specified
if messagesToBeSent.count != 0{ //messages waiting to be sent
thisMessage = messagesToBeSent[0]
data = messagesToBeSent[0].dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
messagesToBeSent.removeAtIndex(0)
}
else{ //no data to be sent
//no message specified and nothing to be sent
return
}
}
else{
thisMessage = message!
data = message!.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
}
//println("Sent the following")
wait()
let bytesWritten = self.output!.write(UnsafePointer(data.bytes), maxLength: data.length)
lastSentMessageID++
//println(thisMessage)
//println("Message sent to server and response is")
//println(bytesWritten) //int count
}
else{ //steam busy
println("no space available in stream")
if message != nil{
messagesToBeSent.append(message!)
}
}
}
func sendMessage(message:String, from:String, to:String){
let xmlMessage = "<message to='\(to)@mydomain.com' from='\(from)@mydomain.com' type='chat' xml:lang='en'> <body>\(message)</body></message>"
send(xmlMessage)
}
func wait() {
while true {
//println("waiting")
if lastSentMessageID == lastReceivedMessageID {
break
}
NSRunLoop.currentRunLoop().runUntilDate(NSDate(timeIntervalSinceNow: 0.1));
NSThread.sleepForTimeInterval(0.1)
}
}
}
我看到两件事可能会导致这种情况。要么将其移动到自己的类中并创建一个实例，要么更改继承关系。思考第一个可能性时，我正在查看线程代码：
self.input!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
在检查streamStatus.toRaw()后，它显示为1，即NSStreamStatusOpening。我不确定这是否会改变。