1.github上的demo

insidegui/MultipeerDemo – github

insidegui/MultipeerKit – github（我用的是这个写我的项目）

2.特别说明：Info.plist 要求

Info.plist 要求
从 iOS 14 开始，为了使 MultipeerKit 正常工作，您需要在应用的 Info.plist 文件中包含两个关键字。

这些键是 Privacy - Local Network Usage Description (NSLocalNetworkUsageDescription) 和 Bonjour services (NSBonjourServices)。

对于隐私键，包括一个人类可读的描述，说明用户允许您的应用访问本地网络上的设备的好处是什么。

Bonjour 服务键是您的应用将要浏览的服务类型的数组。对于 MultipeerKit，该条目的格式应为 _servicename._tcp，其中 servicename 是您在 MultipeerConfiguration 中设置的 serviceType。如果您使用的是默认配置，此键的值应为 _MKSVC._tcp。

3.1 info.plist没有配置正确会报-72008的错误

2023-08-24 15:16:45.917165+0800 RemoteCamera[5294:3939055] [MultipeerConnection] resume()
2023-08-24 15:16:45.923267+0800 RemoteCamera[5294:3939256] [MCNearbyServiceBrowser] NSNetServiceBrowser did not search with error dict [{
    NSNetServicesErrorCode = "-72008";
    NSNetServicesErrorDomain = 10;
}].
2023-08-24 15:16:45.923357+0800 RemoteCamera[5294:3939255] [MCNearbyServiceAdvertiser] Server did not publish: errorDict [{
    NSNetServicesErrorCode = "-72008";
    NSNetServicesErrorDomain = 10;
}].
2023-08-24 15:16:45.923403+0800 RemoteCamera[5294:3939055] [MultipeerConnection] The multipeer connection failed to start browsing for peers. This could be due to missing keys in your app's Info.plist, check out the documentation at http://github.com/insidegui/MultipeerKit for more information. Error: Error Domain=NSNetServicesErrorDomain Code=-72008 "(null)"
2023-08-24 15:16:45.923508+0800 RemoteCamera[5294:3939055] [MultipeerConnection] The multipeer connection failed to start advertising to peers. This could be due to missing keys in your app's Info.plist, check out the documentation at http://github.com/insidegui/MultipeerKit for more information. Error: Error Domain=NSNetServicesErrorDomain Code=-72008 "(null)"

3.我用MultipeerKit写我自己的demo测试成功

3.1 发数据界面

3.2 收数据界面

3.3 代码

func printXY(_ any:Any,obj:Any,line:Int) {
 #if DEBUG
    let date = Date()
     let timeFormatter = DateFormatter()
     //日期显示格式，可按自己需求显示
     timeFormatter.dateFormat = "HH:mm:ss.SSS"
     let strNowTime = timeFormatter.string(from: date) as String
     print("\(strNowTime) \(type(of: obj)) \(line)： \(any)")
  #endif
}



import UIKit
import MultipeerKit
import Combine

struct ExamplePayload: Hashable, Codable {
    let message: String
}


class ViewController: UIViewController{

    private lazy var transceiver: MultipeerTransceiver = {
      var config = MultipeerConfiguration.default
      config.serviceType = "uservc"
     //加了这一句代码availablePeers会自动连接，不加就不会连接，发不了数据
     config.security.encryptionPreference = .required
     
      let t = MultipeerTransceiver(configuration: config)
      
        t.receive(ExamplePayload.self) { [weak self] payload,arg  in
            printXY("收到的数据：\(payload)", obj: self, line: #line)
        self?.receivedDataLabel.text = payload.message
      }
        
      return t
    }()

    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var receivedDataLabel: UILabel!
    

    var dataSource: MultipeerDataSource!
    var cancellable: AnyCancellable?
    
    override func viewDidLoad() {
        super.viewDidLoad()
       
        
        dataSource = MultipeerDataSource(transceiver: transceiver)
               
               // 订阅 availablePeers 的变化
               cancellable = dataSource.$availablePeers.sink { newPeers in
//                   print("New available peers: \(newPeers)")
                   printXY("New available peers: \(newPeers)", obj: self, line: #line)
                   // 在这里你可以更新 UI，例如刷新一个表视图
               }
        
        transceiver.resume()
    }

    deinit {
        // 取消订阅
        cancellable?.cancel()
    }
  

    @IBAction func connectDevices() {
        
    }

    @IBAction func sendMessage() {

        let payload = ExamplePayload(message: textField.text ?? "123")
        printXY("发送的数据：\(payload)", obj: self, line: #line)

        dataSource.transceiver.send(payload, to: dataSource.availablePeers)
    }






}

相关博客：
MultipeerConnectivity框架详细解析（二） —— 一个简单示例（一） 简书