检查 swift 中是否有可用的互联网连接 [重复]

Question

是否有用于检测是否有互联网连接的 Apple 框架包？目前，当我的应用程序在没有互联网连接的情况下尝试对用户的位置进行地理定位时，它会崩溃。

/*inside locationManager didUpdateLocations method*/
var currentLocation:CLLocation? = locations[0] as? CLLocation
geocoder = CLGeocoder()
//Crashes on line below when there isn't an internet connection
//Need to add function to check if internet connection is live 
//Before running reverseGeocodeLocation
geocoder.reverseGeocodeLocation (currentLocation,handleGeocode)

我对 swift 和 ios 编程有点陌生 - 抱歉。

Answer 1

不是一个成熟的网络检查库，但我发现this 是检查网络可用性的简单方法。我设法将它翻译成 Swift，这里是最终代码。

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) ? true : false
    }

}

它适用于 3G 和 WiFi 连接。我还通过一个工作示例将其上传到我的Github。如果您正在寻找一种纯粹在 Swift 中检查网络可用性的简单方法，您可以使用它。

Answer 2

使用 Babatunde 的代码示例，但这里是 Swift 2.0 和错误处理的更新版本： 编辑：还将 Google 的 URL 更改为 iOS 9 的 HTTPS。 EDIT2：原文：http://www.brianjcoleman.com/tutorial-check-for-internet-connection-in-swift/

import Foundation
import SystemConfiguration

public class Reachability {

    // Check if internet connection is available

    class func isConnectedToNetwork() -> Bool {

        var status:Bool = false

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

        var response:NSURLResponse?

        do {
            let _ = try NSURLConnection.sendSynchronousRequest(request, returningResponse: &response) as NSData?
        }
        catch let error as NSError {
            print(error.localizedDescription)
        }

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

Answer 3

由于 Reachability 尚未完全移植到 swift，您可以使用下面的示例代码检查互联网连接：

public class Reachability {
/**
 * Check if internet connection is available
 */
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
  }
}

查看以下函数的示例用法：

// Check if internet is available before proceeding further
    if Reachability.isConnectedToNetwork() {
        // Go ahead and fetch your data from the internet
        // ...
    } else {
        println("Internet connection not available")

        var alert = UIAlertView(title: "No Internet connection", message: "Please ensure you are connected to the Internet", delegate: nil, cancelButtonTitle: "OK")
        alert.show()
    }