检查 Swift 中的互联网连接可用性

Question

有没有办法使用 Swift 检查互联网连接是否可用？

我知道有很多第三方库可以做到这一点，但它们都是用 Objective-C 编写的。我正在寻找 Swift 替代方案。

Answer 1

如果你在你的项目中使用 Alamofire，你可以使用这个示例函数：

import Alamofire

class Network {

    func isConnected(_ complition: @escaping(Bool) -> Void) {
        let retVal = NetworkReachabilityManager()!.isReachable
        complition(retVal)
    }

}

Answer 2

我找到了所有答案中最好的，并且每次都会继续检查 Internet 连接状态。

要开始，首先为网络框架添加一个导入：

import Network

接下来，创建一个 NWPathMonitor 实例

let monitor = NWPathMonitor()

要试试这个，

 monitor.pathUpdateHandler = { path in
    if path.status == .satisfied {
      print("We're connected!")
    } else {
      print("No connection.")
    }
    print(path.isExpensive)
 }

请记住，每次连接状态更改时都会调用该闭包。

 let queue = DispatchQueue(label: "Monitor")
 monitor.start(queue: queue)

这里我是如何在我的视图控制器中使用它的，

class testViewController: UIViewController {

@IBOutlet weak var status: UILabel!
let monitor = NWPathMonitor()

override func viewDidLoad() {
    super.viewDidLoad()
    
    let queue = DispatchQueue(label: "Monitor")
    monitor.start(queue: queue)
    _ = NWPathMonitor(requiredInterfaceType: .cellular)
    
    monitor.pathUpdateHandler = { path in
        if path.status == .satisfied {
            print("We're connected!")
            DispatchQueue.main.async {
                self.status.text = "We're connected!"
            }
            
        } else {
            print("No connection.")
            DispatchQueue.main.async {
                self.status.text = "No connection."
            }  
        }
    }
 }

Answer 3

斯威夫特 4

if isInternetAvailable() {
    print("if called Internet Connectivity success \(isInternetAvailable())");
} else {
    print("else called Internet Connectivity success \(isInternetAvailable())");
}

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)
   //   print(isReachable && !needsConnection)
   return (isReachable && !needsConnection)
}

Answer 4

对于 Swift 5：

import Network
let monitor = NWPathMonitor()

func checkInterwebs() -> Bool {
    var status = false
    monitor.pathUpdateHandler = { path in
        if path.status == .satisfied {
            status = true  // online
        }
    }
    return status
}

Answer 5

正如 cmets 中提到的，虽然它可以在 Swift 中使用 Objective-C 库，但我想要一个更纯粹的 Swift 解决方案。现有的 Apple Reachability 类和其他第三方库对于我来说似乎太复杂而无法转换为 Swift。我在 Google 上搜索了更多内容，发现了这个 article，它显示了一种检查网络可用性的简单方法。我开始把它翻译成 Swift。我遇到了很多snags，但感谢来自 StackOverflow 的Martin R，我设法解决了这些问题，并最终在 Swift 中找到了一个可行的解决方案。这是代码。

import Foundation
import SystemConfiguration

public class Reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)

        let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
            SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0)).takeRetainedValue()
        }

        var flags: SCNetworkReachabilityFlags = 0
        if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
            return false
        }

        let isReachable = (flags & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags & UInt32(kSCNetworkFlagsConnectionRequired)) != 0

        return isReachable && !needsConnection
    }

}

对于 Swift > 3.0

public class Reachability {
    public func isConnectedToNetwork() -> Bool {
        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
        zeroAddress.sin_family = sa_family_t(AF_INET)

        guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
                SCNetworkReachabilityCreateWithAddress(nil, $0)
            }
        }) else {
            return false
        }

        var flags: SCNetworkReachabilityFlags = []
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return false
        }
        if flags.isEmpty {
            return false
        }

        let isReachable = flags.contains(.reachable)
        let needsConnection = flags.contains(.connectionRequired)

        return (isReachable && !needsConnection)
    }
}

这适用于 3G 和 WiFi 连接。我还通过一个工作示例将其上传到我的GitHub。

Answer 6

SWIFT 3： 检查 wifi 和 internet 连接：

import Foundation
import SystemConfiguration

public class Reachability {
    public func isConnectedToNetwork() -> Bool {
        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
        zeroAddress.sin_family = sa_family_t(AF_INET)

        guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
                SCNetworkReachabilityCreateWithAddress(nil, $0)
            }
        }) else {
            return false
        }

        var flags: SCNetworkReachabilityFlags = []
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return false
        }

        let isReachable = flags.contains(.reachable)
        let needsConnection = flags.contains(.connectionRequired)

        return (isReachable && !needsConnection)
    }
}

用法：

if Reachability.isConnectedToNetwork() == true {
    print("Connected to the internet")
    //  Do something
} else {
    print("No internet connection")
    //  Do something
}

Answer 7

SWIFT 3：检查 3G 和 Wi-Fi 连接

DispatchQueue.main.async {
        let url = URL(string: "https://www.google.com")!
        let request = URLRequest(url: url)

        let task = URLSession.shared.dataTask(with: request) {data, response, error in

            if error != nil {
                // do something here...
                print("Internet Connection not Available!")
            }
            else if let httpResponse = response as? HTTPURLResponse {
                if httpResponse.statusCode == 200 {
                    // do something here...
                    print("Internet Connection OK")
                }
                print("statusCode: \(httpResponse.statusCode)")
            }

        }
        task.resume()
}

Answer 8

适用于 Swift 3.1 (iOS 10.1)

如果您想区分网络类型（即 WiFi 或 WWAN）：

你可以使用：

func checkWiFi() -> Bool {

    let networkStatus = Reachability().connectionStatus()
    switch networkStatus {
    case .Unknown, .Offline:
        return false
    case .Online(.WWAN):
        print("Connected via WWAN")
        return true
    case .Online(.WiFi):
        print("Connected via WiFi")
        return true
    }
}

这是区分网络类型的整个可达性类：

import Foundation
import SystemConfiguration

import UIKit
import SystemConfiguration.CaptiveNetwork

public let ReachabilityStatusChangedNotification = "ReachabilityStatusChangedNotification"

public enum ReachabilityType: CustomStringConvertible {
    case WWAN
    case WiFi

    public var description: String {
        switch self {
        case .WWAN: return "WWAN"
        case .WiFi: return "WiFi"
        }
    }
}

public enum ReachabilityStatus: CustomStringConvertible  {
    case Offline
    case Online(ReachabilityType)
    case Unknown

    public var description: String {
        switch self {
        case .Offline: return "Offline"
        case .Online(let type): return "Online (\(type))"
        case .Unknown: return "Unknown"
        }
    }
}

public class Reachability {

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

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

        var flags : SCNetworkReachabilityFlags = []
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return .Unknown
        }

        return ReachabilityStatus(reachabilityFlags: flags)
    }

    func monitorReachabilityChanges() {
        let host = "google.com"
        var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
        let reachability = SCNetworkReachabilityCreateWithName(nil, host)!

        SCNetworkReachabilitySetCallback(reachability, { (_, flags, _) in
            let status = ReachabilityStatus(reachabilityFlags: flags)

            NotificationCenter.default.post(name: NSNotification.Name(rawValue: ReachabilityStatusChangedNotification), object: nil, userInfo: ["Status": status.description])}, &context)

        SCNetworkReachabilityScheduleWithRunLoop(reachability, CFRunLoopGetMain(), CFRunLoopMode.commonModes.rawValue)
    }
}

extension ReachabilityStatus {

    public init(reachabilityFlags flags: SCNetworkReachabilityFlags) {
        let connectionRequired = flags.contains(.connectionRequired)
        let isReachable = flags.contains(.reachable)
        let isWWAN = flags.contains(.isWWAN)

        if !connectionRequired && isReachable {
            if isWWAN {
                self = .Online(.WWAN)
            } else {
                self = .Online(.WiFi)
            }
        } else {
            self =  .Offline
        }
    }
}

Answer 9

由于不推荐使用 sendSynchronousRequest，我尝试了这个，但在响应完成之前调用了“返回状态”。

这个答案很有效，Check for internet connection with Swift

这就是我尝试过的：

import Foundation

public class Reachability {

    class func isConnectedToNetwork()->Bool{

        var Status:Bool = false
        let url = NSURL(string: "http://google.com/")
        let request = NSMutableURLRequest(URL: url!)
        request.HTTPMethod = "HEAD"
        request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData
        request.timeoutInterval = 10.0
        let session = NSURLSession.sharedSession()

        session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
            print("data \(data)")
            print("response \(response)")
            print("error \(error)")

            if let httpResponse = response as? NSHTTPURLResponse {
                print("httpResponse.statusCode \(httpResponse.statusCode)")
                if httpResponse.statusCode == 200 {
                    Status = true
                }
            }

        }).resume()


        return Status
    }
}

Answer 10

你也可以使用下面的答案。

    func checkInternet(flag:Bool, completionHandler:(internet:Bool) -> Void)
    {
      UIApplication.sharedApplication().networkActivityIndicatorVisible = true

      let url = NSURL(string: "http://www.google.com/")
      let request = NSMutableURLRequest(URL: url!)

      request.HTTPMethod = "HEAD"
      request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData
      request.timeoutInterval = 10.0

      NSURLConnection.sendAsynchronousRequest(request, queue:NSOperationQueue.mainQueue(), completionHandler:
      {(response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in

        UIApplication.sharedApplication().networkActivityIndicatorVisible = false

        let rsp = response as NSHTTPURLResponse?

        completionHandler(internet:rsp?.statusCode == 200)
    })
    }

     func yourMethod()
    {
    self.checkInternet(false, completionHandler:
    {(internet:Bool) -> Void in

        if (internet)
        {
            // "Internet" mean Google
        }
        else
        {
            // No "Internet" no Google
        }
    })
   }

Answer 11

我给你更好的方法……

您必须使用此代码创建一个类

 import Foundation
 public class Reachability {

class func isConnectedToNetwork()->Bool{

    var Status:Bool = false
    let url = NSURL(string: "http://google.com/")
    let request = NSMutableURLRequest(URL: url!)
    request.HTTPMethod = "HEAD"
    request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData
    request.timeoutInterval = 10.0

    var response: NSURLResponse?

    var data = NSURLConnection.sendSynchronousRequest(request, returningResponse: &response, error: nil) as NSData?

    if let httpResponse = response as? NSHTTPURLResponse {
        if httpResponse.statusCode == 200 {
            Status = true
        }
    }

    return Status
  }
}

然后您可以使用以下代码检查项目中任何地方的互联网连接：

if Reachability.isConnectedToNetwork() == true {
     println("Internet connection OK")
} else {
     println("Internet connection FAILED")
}

非常简单！

*这种方式是基于维克拉姆波特的回答！