从 Swift 客户端上的 TCP 服务器获取响应

Question

我正在尝试使用 GCDAsyncSocket 快速编写一个 TCP 套接字客户端，但我遇到了一个问题。在我的代码中，我有一个 NSTextField（称为框），这是我的代码：

import Cocoa

class AppDelegate: NSObject, NSApplicationDelegate 
{

    @IBOutlet weak var window: NSWindow!
    @IBOutlet weak var box: NSTextField!

    var bsocket: GCDAsyncSocket!

    func applicationDidFinishLaunching(aNotification: NSNotification?)
    {
        bsocket = GCDAsyncSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
        var port:UInt16 = 8090
        if (!bsocket.connectToHost("localhost", onPort: port, error: nil))
        {
            println("Error")
        }
        else
        {
            println("Connecting...")
        }
        var request:String = "Arn.Preg:3302:"
        var data:NSData = request.dataUsingEncoding(NSUTF8StringEncoding)!
        bsocket.writeData(data, withTimeout: -1.0, tag: 0)
        bsocket.readDataWithTimeout(-1.0, tag: 0)
    }

    func applicationWillTerminate(aNotification: NSNotification?) 
    {
        // Insert code here to tear down your application
    }

    func socket(socket : GCDAsyncSocket, didReadData data:NSData, withTag tag:UInt16)
    {
        var response = NSString(data: data, encoding: NSUTF8StringEncoding)
        println("Received Response")
        box.stringValue = box.stringValue + "\n" + response
    }

    func socket(socket : GCDAsyncSocket, didConnectToHost host:String, port p:UInt16)
    {
        println("Connected to \(host) on port \(p).")
        box.stringValue = box.stringValue + "\n" + "Connected to \(host) on port \(p)."
    }
}

func socket(socket : GCDAsyncSocket, didReadData data:NSData, withTag tag:UInt16)

当我在终端中使用 telnet 命令尝试访问我的 TCP 服务器时，结果如下。

Marzuk:~ marzukrashid$ telnet localhost 8090
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Arn.TipoSer:XPL0:

然后，当我输入“Arn.Preg:3302:”时，服务器会返回：

Marzuk:~ marzukrashid$ telnet localhost 8090
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Arn.TipoSer:XPL0:
Arn.Preg:3302:
Arn.Resp:3302=329351:

当我输入“Arn.Preg:3302:”时，服务器返回“Arn.Resp:3302=329351:”，这是我想要达到的结果，我希望我的应用程序中的 NSTextField 显示“Arn .Resp:3302=329351:"。现在，当我运行我的代码时，程序会记录“正在连接...”、“已连接到端口 8090 上的 127.0.0.1。”和“收到的响应”，正如它应该在应用程序本身的 NSTextField 中一样，它显示“连接到端口 8090 上的 127.0.0.1”。和“Arn.TipoSer:XPl0:”，但它没有像我想要的那样显示“Arn.Resp:3302=329351:”。

我的问题是为什么我的代码不这样做，以及如何修复我的代码以执行此操作。

谢谢。

Answer 1

我了解到didReadData函数只有在readDataWithTimeout函数运行时才会运行，所以我在didConnectToHost、didReadData和applicationDidFinishLaunching中加入了readDataWithTimeout函数。我了解到在请求结束时需要一个“\n”来给出终端中使用的返回键，所以我在“Arn.Preg:3302:”中添加了“\n”以使其成为“Arn.Preg :3302:\n"。最终代码如下所示：

import Cocoa

class AppDelegate: NSObject, NSApplicationDelegate {

    @IBOutlet weak var window: NSWindow!
    @IBOutlet weak var box: NSTextField!


    //let bsocket = GCDAsyncSocket(delegate: AppDelegate.self, delegateQueue: dispatch_get_main_queue())
    var bsocket: GCDAsyncSocket!

    func applicationDidFinishLaunching(aNotification: NSNotification?)
    {
        bsocket = GCDAsyncSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
        var port:UInt16 = 8090
        if (!bsocket.connectToHost("localhost", onPort: port, error: nil))
        {
            println("Error.")
        }
        else
        {
            println("Connecting...")
        }
        bsocket.readDataWithTimeout(-1.0, tag: 0)
    }

    func applicationWillTerminate(aNotification: NSNotification?) {
        // Insert code here to tear down your application
    }

    func socket(socket : GCDAsyncSocket, didReadData data:NSData, withTag tag:UInt16)
    {
        var response = NSString(data: data, encoding: NSUTF8StringEncoding)
        println("Received Response")
        box.stringValue = box.stringValue + "\n" + response
        bsocket.readDataWithTimeout(-1.0, tag: 0)
    }

    func socket(socket : GCDAsyncSocket, didConnectToHost host:String, port p:UInt16)
    {
        println("Connected to \(host) on port \(p).")
        box.stringValue = box.stringValue + "\n" + "Connected to \(host) on port \(p)."
        bsocket.readDataWithTimeout(-1.0, tag: 0)
        sendRequest()
    }

    func sendRequest()
    {
        var request:String = "Arn.Preg:3302:\n"
        var data:NSData = request.dataUsingEncoding(NSUTF8StringEncoding)!
        bsocket.writeData(data, withTimeout: -1.0, tag: 0)
    }

}

Answer 2

在我看来，您似乎是在尝试发送 Arn.Preg:3302: 消息并在实际连接之前获得回复。在您的applicationDidFinishLaunching 中，您启动一​​个异步连接，然后立即调用writeData 和readData——您可能需要执行以下操作：

class AppDelegate: NSObject, NSApplicationDelegate 
{

    @IBOutlet weak var window: NSWindow!
    @IBOutlet weak var box: NSTextField!

    var bsocket: GCDAsyncSocket!

    func applicationDidFinishLaunching(aNotification: NSNotification?)
    {
        bsocket = GCDAsyncSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
        var port:UInt16 = 8090
        if (!bsocket.connectToHost("localhost", onPort: port, error: nil))
        {
            println("Error")
        }
        else
        {
            println("Connecting...")
        }
    }

    func socket(socket : GCDAsyncSocket, didReadData data:NSData, withTag tag:UInt16)
    {
        var response = NSString(data: data, encoding: NSUTF8StringEncoding)
        println("Received Response")
        box.stringValue = box.stringValue + "\n" + response
    }

    func socket(socket : GCDAsyncSocket, didConnectToHost host:String, port p:UInt16)
    {
        println("Connected to \(host) on port \(p).")
        box.stringValue = box.stringValue + "\n" + "Connected to \(host) on port \(p)."

        var request:String = "Arn.Preg:3302:"
        var data:NSData = request.dataUsingEncoding(NSUTF8StringEncoding)!
        bsocket.writeData(data, withTimeout: -1.0, tag: 0)
        bsocket.readDataWithTimeout(-1.0, tag: 0)
    }
}