我试图在Swift中使用NSOutputStream和NSInputStream发送和接收数据。发送数据的操作很好,但是我对接收数据有一些疑问。
我找到了一种处理NSStreamEvent的解决方案,并且我已经尝试过了。
首先,这是我的初始化连接函数:
func initNetworkCommunication(){
var host : CFString = "127.0.0.1"
var port : UInt32 = 7001
var readstream : Unmanaged<CFReadStream>?
var writestream : Unmanaged<CFWriteStream>?
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, host, port, &readstream, &writestream)
inputstream = readstream!.takeRetainedValue()
outputstream = writestream!.takeRetainedValue()
inputstream.delegate = self
outputstream.delegate = self
inputstream.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
outputstream.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
inputstream.open()
outputstream.open()
}
这部分代码是有效的。我已经将委托设置为 self,因此应该能够在这个类中处理 NSStreamEvents。
func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
switch (eventCode){
case NSStreamEvent.OpenCompleted:
NSLog("Stream opened")
break
case NSStreamEvent.HasBytesAvailable:
NSLog("HasBytesAvailable")
break
case NSStreamEvent.ErrorOccurred:
NSLog("ErrorOccurred")
break
case NSStreamEvent.EndEncountered:
NSLog("EndEncountered")
break
default:
NSLog("unknown.")
}
}
据我理解,每当有数据到达时,它应该打印“HasBytesAvaible”,但是每次都打印“unknown.”。因此,我稍微尝试了一下,并且使用以下方法解决了问题:
func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
var buffer = [UInt8](count: 4096, repeatedValue: 0)
while (inputstream.hasBytesAvailable){
let result: Int = inputstream.read(&buffer, maxLength: buffer.count)
}
switch (eventCode){
case NSStreamEvent.OpenCompleted:
NSLog("Stream opened")
break
case NSStreamEvent.HasBytesAvailable:
NSLog("HasBytesAvailable")
var output = NSString(bytes: &buffer, length: buffer.count, encoding: NSUTF8StringEncoding)
NSLog("output: %@", output)
receiveMessage(output) //only adds the message to an array
break
case NSStreamEvent.ErrorOccurred:
NSLog("ErrorOccurred")
break
case NSStreamEvent.EndEncountered:
NSLog("EndEncountered")
break
default:
NSLog("unknown.")
}
}
这样做是有效的,但我想问你这是否是正确的方式?在这一点上,最佳实践是什么?
更新 几周前我又重新研究了一下,发现了我的错误。所以这里是可以工作的代码。
func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
switch (eventCode){
case NSStreamEvent.ErrorOccurred:
NSLog("ErrorOccurred")
break
case NSStreamEvent.EndEncountered:
NSLog("EndEncountered")
break
case NSStreamEvent.None:
NSLog("None")
break
case NSStreamEvent.HasBytesAvailable:
NSLog("HasBytesAvaible")
var buffer = [UInt8](count: 4096, repeatedValue: 0)
if ( aStream == inputstream){
while (inputstream.hasBytesAvailable){
var len = inputstream.read(&buffer, maxLength: buffer.count)
if(len > 0){
var output = NSString(bytes: &buffer, length: buffer.count, encoding: NSUTF8StringEncoding)
if (output != ""){
NSLog("server said: %@", output!)
}
}
}
}
break
case NSStreamEvent.allZeros:
NSLog("allZeros")
break
case NSStreamEvent.OpenCompleted:
NSLog("OpenCompleted")
break
case NSStreamEvent.HasSpaceAvailable:
NSLog("HasSpaceAvailable")
break
}