Swift MCSessionState从连接状态更改为未连接状态

每当我尝试使用连接对等方时，对等方的状态将从

MCSessionState.Connecting

更改为

MCSessionState.NotConnected

以下是我运行的事件顺序：

模拟器通过一个网络广告服务

iPhone通过浏览器浏览该服务

iPhone会找到模拟器，并立即邀请它访问 会议通过

最后，模拟器使用

注:

• 尽管我不需要安全性，但我接受客户端发送的任何证书

以下是我正在使用的代码：

import UIKit
import MultipeerConnectivity

class ViewController: UIViewController {
    var advertiser: MCNearbyServiceAdvertiser!
    var browser: MCNearbyServiceBrowser!
    var session: MCSession!

    override func viewDidLoad() {
        super.viewDidLoad()
        let localPeerID = MCPeerID(displayName: UIDevice.currentDevice().name)
        session = MCSession(peer: localPeerID, securityIdentity: nil, encryptionPreference: MCEncryptionPreference.None)
        session.delegate = self
    }

    @IBAction func hostTapped(sender: AnyObject) {
        let localPeerID = MCPeerID(displayName: UIDevice.currentDevice().name)
        advertiser = MCNearbyServiceAdvertiser(peer: localPeerID, discoveryInfo: nil, serviceType: "abc")
        advertiser.delegate = self
        print("started advertising")
        advertiser.startAdvertisingPeer()
    }

    @IBAction func connectTapped(sender: AnyObject) {
        let localPeerID = MCPeerID(displayName: UIDevice.currentDevice().name)
        browser = MCNearbyServiceBrowser(peer: localPeerID, serviceType: "abc")
        browser.delegate = self
        print("started searching")
        browser.startBrowsingForPeers()
    }
}

extension ViewController: MCNearbyServiceAdvertiserDelegate {
    func advertiser(advertiser: MCNearbyServiceAdvertiser, didReceiveInvitationFromPeer peerID: MCPeerID, withContext context: NSData?, invitationHandler: (Bool, MCSession) -> Void) {
        print("accepting invitation from \(peerID.displayName)")
        invitationHandler(true, session)
    }

    func advertiser(advertiser: MCNearbyServiceAdvertiser, didNotStartAdvertisingPeer error: NSError) {
        print("did not start advertising \(error)")
    }
}

extension ViewController: MCSessionDelegate {
    func session(session: MCSession, peer peerID: MCPeerID, didChangeState state: MCSessionState) {
        print("\(peerID.displayName) changed state: \(state.toString())")
    }

    func session(session: MCSession, didReceiveData data: NSData, fromPeer peerID: MCPeerID) {

    }

    func session(session: MCSession, didReceiveStream stream: NSInputStream, withName streamName: String, fromPeer peerID: MCPeerID) {

    }

    func session(session: MCSession, didStartReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, withProgress progress: NSProgress) {

    }

    func session(session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, atURL localURL: NSURL, withError error: NSError?) {

    }

    func session(session: MCSession, didReceiveCertificate certificate: [AnyObject]?, fromPeer peerID: MCPeerID, certificateHandler: (Bool) -> Void) {
        certificateHandler(true)
    }
}

extension ViewController: MCNearbyServiceBrowserDelegate {
    func browser(browser: MCNearbyServiceBrowser, foundPeer peerID: MCPeerID, withDiscoveryInfo info: [String : String]?) {
        print("found \(peerID.displayName), inviting to session")
        browser.invitePeer(peerID, toSession: session, withContext: nil, timeout: 30)
    }

    func browser(browser: MCNearbyServiceBrowser, lostPeer peerID: MCPeerID) {
        print("lost \(peerID.displayName)")
    }
}

extension MCSessionState {
    func toString() -> String {
        switch self {
        case .Connected:    return "Connected"
        case .Connecting:   return "Connecting"
        case .NotConnected: return "Not Connected"
        }
    }
}

但是，有一个类似的例子，链接的代码很旧，无法再访问。此外，问题在于使用的是同一个会话对象。

我使用的是不同的MCSession、MCNearbyServiceAdvertiser和MCNearbyServiceBrowser实例

为了修复它，我创建了一个mcpeirid实例变量：

var localPeerID: MCPeerID?

override func viewDidLoad() {
    // ...
    localPeerID = MCPeerID(displayName: UIDevice.currentDevice().name)
    // ...
}

。。。并使用它而不是将它们创建为局部变量（

让localPeerID=…

）

---

它现在正确地从连接状态转到连接状态。

始终可以将其创建为类的常量

class ViewController: UIViewController {
    var advertiser: MCNearbyServiceAdvertiser!
    var browser: MCNearbyServiceBrowser!
    var session: MCSession!

    let localPeerID = MCPeerID(displayName: UIDevice.currentDevice().name)
    ...
}

---

我也有同样的问题。谢谢分享。我个人不喜欢在生产代码中强制展开，除非真的没办法。通过将其设置为常量并在声明点或延迟加载点进行初始化，可以显著提高安全性：）