如何在iOS swift中获取AVAHI发布的服务的IP和端口

Question

我正在使用NSNetServiceBrowser，能够在"didFindService"中找到AVAHI发布的服务列表，如下所示：服务出现：本地。_https._TCP.TEMP-Mobileyes5-1C497B9ED382 -1服务出现：本地。_https._TCP.TEMP-Mobileyes5-1C497B8E3916 -1服务出现：本地。_https._TCP.TEMP-Mobileyes5-1C497B9ED380 -1

但找不到相同服务的IP地址和端口号。我发现代码无法到达"netServiceDidResolveAddress"，我的代码是：

class ServiceDiscovery : NSObject, NSNetServiceBrowserDelegate,NSNetServiceDelegate {
    var _browser:NSNetServiceBrowser!
    var _service: NSNetService!
    var services = [NSNetService]()
    override init() {
        _browser = NSNetServiceBrowser()
        super.init()
        _browser.delegate = self
        _browser.includesPeerToPeer = true
        _browser.searchForServicesOfType("_https._tcp.", inDomain: "local.")
        _browser.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
    }

    func netServiceBrowser(browser: NSNetServiceBrowser, didFindDomain domainString: String, moreComing: Bool) {
        print(domainString)
    }
    func netServiceBrowser(aNetServiceBrowser: NSNetServiceBrowser, didFindService aNetService: NSNetService, moreComing: Bool) {
       print("Service appeared: (aNetService)")
        services.append(aNetService)
        aNetService.delegate = self
        aNetService.resolveWithTimeout(5.0)
    }

    func netServiceBrowser(browser: NSNetServiceBrowser, didNotSearch errorDict: [String : NSNumber]) {
        print(errorDict)
    }
    func netServiceBrowser(browser: NSNetServiceBrowser, didRemoveService service: NSNetService, moreComing: Bool) {
        print("Service removed: (service)")
    }
    func netService(sender: NSNetService, didNotResolve errorDict: [String : NSNumber]) {
        print(errorDict)
    }
    func netServiceDidResolveAddress(sender: NSNetService) {
        print(sender.addresses![0])
    }

}

Answer 1

出现问题的可能原因可能是您正在调用

aNetService.resolveWithTimeout(5.0)

在另一个函数中，所以只要

didFindService

完成后，局部变量 aNetService 被销毁(因为它是 didFindService 函数的局部变量(

溶液

我看到您已经在顶部定义了一个名为"_service">的类范围变量因此，通过使用

_service = aNetService
_service.resolveWithTimeout(5.0)

在你的 didFindService 里面这应该可以解决您的问题。而且，netServiceDidResolveAddress现在应该被调用。

Answer 2

import Foundation
class ServiceDiscovery : NSObject, NetServiceBrowserDelegate,NetServiceDelegate {
    var _browser:NetServiceBrowser!
    var _service: NetService!
    var services = [NetService]()

    func searchServices(){
        self.services.removeAll()
        _browser = NetServiceBrowser()
        _browser.delegate = self
        _browser.includesPeerToPeer = true
        _browser.searchForServices(ofType: "_https._tcp.", inDomain: "local.")
        _browser.schedule(in: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
    }

    func updateInterface () {
        for service in self.services {
            if service.port == -1 {
                print("service (service.name) of type (service.type)" +
                    " not yet resolved")
                service.delegate = self
                service.resolve(withTimeout: 0.0)
            } else {
                let deviceLanController = DeviceLanController()
                let dict = NetService.dictionary(fromTXTRecord: service.txtRecordData()!)
                let id = self.copyStringFromTXTDict(dict as [AnyHashable: Any]?, which: "id")
                var ipAdd = ""
                if let address = service.addresses{
                if let addressOfFirstDevice = address.first{
                    let theAddress = addressOfFirstDevice as Data
                    var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                    if getnameinfo((theAddress as NSData).bytes.bindMemory(to: sockaddr.self, capacity: theAddress.count), socklen_t(theAddress.count),
                                   &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
                        if let numAddress = String(validatingUTF8: hostname) {
                            ipAdd = numAddress
                        }
                    }
                    if let serviceId = id{
                        deviceLanController.setDeviceAvailable(serviceId, host: ipAdd, port: "(service.port)")
                    }
                }
                }
            }
        }
    }

    fileprivate func copyStringFromTXTDict(_ dict: [AnyHashable: Any]?, which: String) -> String? {
        // Helper for getting information from the TXT data
        var resultString: String? = nil
        if let data = dict?[which as NSObject] as! Data? {
            resultString = String(data: data, encoding: String.Encoding.utf8)!
        }
        return resultString
    }

    func netServiceBrowser(_ browser: NetServiceBrowser, didFindDomain domainString: String, moreComing: Bool) {
        print("didFindDomain")
        print(domainString)
    }
    func netServiceBrowser(_ aNetServiceBrowser: NetServiceBrowser, didFind aNetService: NetService, moreComing: Bool) {
        print("didFindService")
        self.services.append(aNetService)
        if !moreComing {
            aNetService.stop()
            self.updateInterface()
        }
    }
    func netServiceBrowser(_ browser: NetServiceBrowser, didRemove service: NetService, moreComing: Bool){
        print("didRemoveService")
        if let ix = self.services.index(of: service) {
            self.services.remove(at: ix)
            print("removing a service")
            if !moreComing {
                self.updateInterface()
            }
        }
    }
    func netServiceBrowser(_ browser: NetServiceBrowser, didNotSearch errorDict: [String : NSNumber]) {
        print("didNotSearch")
        print(errorDict)
    }

    func netService(_ sender: NetService, didNotResolve errorDict: [String : NSNumber]) {
        print("didNotResolve",sender)
        print(errorDict)
    }
    func netServiceWillResolve(_ sender: NetService) {
        print("netServiceWillResolve",sender)
    }
    func netServiceDidResolveAddress(_ sender: NetService) {
        print("netServiceDidResolveAddress",sender)
       self.updateInterface()
    }
}

这个答案解决了我的问题。我正在解析并保存在我的核心数据中，以便我可以使用该地址连接本地服务。