swift 判断当前设备网络是否可用

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

}

}

if Reachability.isConnectedToNetwork(){

println("网络正常")

}else{

println("网络异常")

}