类型“类”不符合协议“MCSessionDelegate”

Posted 2023-03-11

【中文标题】类型“类”不符合协议“MCSessionDelegate”

【英文标题】：Type 'Class' does not conform to protocol 'MCSessionDelegate'

【发布时间】：2018-08-13 02:01:22

【问题描述】：

我正在将我的代码从 Swift 2.X 迁移到 3.X，并且已经解决了我的大部分运行时错误，除了一个不断出现的错误。 我拥有所有必需的功能，并且已经清理并删除了派生数据，但它仍然说我的类不符合“MCSessionDelegate”。 `

import MultipeerConnectivity
import Foundation

class Cashier: Advertiser

var waiterBecomesConnectedHandler: ((MCPeerID) -> Void)?
var waiterBecomesDisconnectedHandler: ((MCPeerID) -> Void)?


extension Cashier: MCSessionDelegate


@available(ios 7.0, *)
func session(_ session: MCSession, didStartReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, with progress: Progress) 



@available(iOS 7.0, *)
func session(_ session: MCSession, peer peerID: MCPeerID, didChange state: MCSessionState) 
    switch state 
        case .notConnected:
            waiterBecomesDisconnectedHandler?(peerID)
            connectedPeerSessions.removeValue(forKey: peerID)
            break

        case .connected:
            waiterBecomesConnectedHandler?(peerID)
            break

        case .connecting:
            break
    



@available(iOS 7.0, *)
func session(_ session: MCSession, didReceive data: Data, fromPeer peerID: MCPeerID) 



@available(iOS 7.0, *)
func session(_ session: MCSession, didReceive stream: InputStream, withName streamName: String, fromPeer peerID: MCPeerID) 




@available(iOS 7.0, *)
func session(_ session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, at localURL: URL, withError error: Error?)


`

这是协议的代码 `

// Delegate methods for MCSession.
public protocol MCSessionDelegate : NSObjectProtocol 


// Remote peer changed state.
@available(iOS 7.0, *)
public func session(_ session: MCSession, peer peerID: MCPeerID, didChange state: MCSessionState)


// Received data from remote peer.
@available(iOS 7.0, *)
public func session(_ session: MCSession, didReceive data: Data, fromPeer peerID: MCPeerID)


// Received a byte stream from remote peer.
@available(iOS 7.0, *)
public func session(_ session: MCSession, didReceive stream: InputStream, withName streamName: String, fromPeer peerID: MCPeerID)


// Start receiving a resource from remote peer.
@available(iOS 7.0, *)
public func session(_ session: MCSession, didStartReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, with progress: Progress)


// Finished receiving a resource from remote peer and saved the content
// in a temporary location - the app is responsible for moving the file
// to a permanent location within its sandbox.
@available(iOS 7.0, *)
public func session(_ session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, at localURL: URL, withError error: Error?)


// Made first contact with peer and have identity information about the
// remote peer (certificate may be nil).
@available(iOS 7.0, *)
optional public func session(_ session: MCSession, didReceiveCertificate certificate: [Any]?, fromPeer peerID: MCPeerID, certificateHandler: @escaping (Bool) -> Swift.Void)
`

【问题讨论】：

您真的在构建应用程序以向后兼容 iOS = 7.0。在大多数情况下，您不应再针对这些旧版本的 iOS。

@ekscrypto 感谢您的建议*。我删除了 @available(...) 并将我的 iOS 目标更改为 8.0，现在它告诉我添加我的代码中已有的 didStartReceivingResourceWithName 存根。

它应该在警告气泡中有一个“修复”按钮。如果您单击它检查它创建的存根，很可能您有一个类型错误或参数名称已更改

我点击了修复按钮，它显示的功能完全相同。我错过了什么吗？

【参考方案1】：

从扩展中删除所有功能

 extension Cashier: MCSessionDelegate.

您会看到缺少 subs 的错误，点击修复选项，它会自动添加所有需要的功能 如果以上两个步骤都不起作用，请尝试清理构建文件夹并重新启动 Xcode

【讨论】：

感谢您的回答，我执行了上述步骤，但仍然显示我的课程仍然不符合协议。

请分享 MCSessionDelegate 的协议代码或者repo链接

试试下面 Ashley Mills 发布的答案。好像是这个问题

【参考方案2】：

您的委托方法之一是错误的。 at localURL: URL 应该是 at localURL: URL?

func session(_ session: MCSession, 
didFinishReceivingResourceWithName resourceName: String, 
    fromPeer peerID: MCPeerID, 
          at localURL: URL?, 
   withError error: Error?)

https://developer.apple.com/documentation/multipeerconnectivity/mcsessiondelegate/1406984-session