MCSessionState从连接状态变为未连接状态

Question

每当我尝试使用Multipeer Connectivity Framework连接对等体时，对等体的状态将从MCSessionState.Connecting更改为MCSessionState.NotConnected。

这里是我跑的事件顺序：

1. 模拟器通过MCNearbyServiceAdvertiser通告服务。
2. iPhone通过MCNearbyServiceBrowser浏览服务。
3. iPhone找到模拟器并立即通过invitePeer(_:toSession:withContext:timeout:)邀请它参加 会话。
4. 最后，模拟器接受使用 advertiser(_:didReceiveInvitationFromPeer:withContext:invitationHandler:)的邀请。

注：

• 即使我不要求安全，我接受由客户in case that is the bug发送的任何证书。

这里是我使用的代码：

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" 
     } 
    } 
} 

有一个类似question here，然而，链接的代码是旧的，不能再访问。此外，问题在于正在使用相同的会话对象。

Answer 1

我正在为MCSession，MCNearbyServiceAdvertiser和MCNearbyServiceBrowser使用不同的MCPeerID实例。

为了解决这个问题，我创建了一个MCPeerID实例变量：

var localPeerID: MCPeerID? 

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

...并使用它，而不是创建为局部变量（let localPeerID = ...）的。

它现在从连接到正确连接状态。

Answer 2

总是可以创建它作为一个常量的类！

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

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