MCSessionState從連接狀態變爲未連接狀態

Question

每當我嘗試使用Multipeer Connectivity Framework連接對等體時，對等體的狀態將從MCSessionState.Connecting更改爲MCSessionState.NotConnected。

這裏是我跑的事件順序：

1. 模擬器通過MCNearbyServiceAdvertiser通告服務。
2. iPhone通過MCNearbyServiceBrowser瀏覽服務。
3. iPhone找到模擬器並立即通過invitePeer(_:toSession:withContext:timeout:)邀請它參加 會話。
4. 最後，模擬器接受使用 advertiser(_:didReceiveInvitationFromPeer:withContext:invitationHandler:)的邀請。

注：

• 即使我不要求安全，我接受由客戶in case that is the bug發送的任何證書。

這裏是我使用的代碼：

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" 
     } 
    } 
} 

有一個類似question here，然而，鏈接的代碼是舊的，不能再訪問。此外，問題在於正在使用相同的會話對象。

Answer 1

我正在爲MCSession，MCNearbyServiceAdvertiser和MCNearbyServiceBrowser使用不同的MCPeerID實例。

爲了解決這個問題，我創建了一個MCPeerID實例變量：

var localPeerID: MCPeerID? 

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

...並使用它，而不是創建爲局部變量（let localPeerID = ...）的。

它現在從連接到正確連接狀態。

Answer 2

總是可以創建它作爲一個常量的類！

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

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