如果没有网络连接，则显示警报

Question

如何通知用户与swift没有网络连接3.我已经尝试了一堆解决方案，目前为止他们都没有工作。我不在寻找网络连接的速度

Answer 1

有很多资源显示如何检查Internet连接。例如，从this。

func isInternetAvailable() -> Bool 
    { 
     var zeroAddress = sockaddr_in() 
     zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress)) 
     zeroAddress.sin_family = sa_family_t(AF_INET) 

     let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) { 
      $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in 
       SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress) 
      } 
     } 

     var flags = SCNetworkReachabilityFlags() 
     if !SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) { 
      return false 
     } 
     let isReachable = flags.contains(.reachable) 
     let needsConnection = flags.contains(.connectionRequired) 
     return (isReachable && !needsConnection) 
    } 

    func showAlert() { 
     if !isInternetAvailable() { 
      let alert = UIAlertController(title: "Warning", message: "The Internet is not available", preferredStyle: .alert) 
      let action = UIAlertAction(title: "Dismiss", style: .default, handler: nil) 
      alert.addAction(action) 
      present(alert, animated: true, completion: nil) 
     } 
    } 

您需要导入：

import Foundation 
import SystemConfiguration