问题
Is there a way to check if the internet connection is available using Swift?
I know there are many third party libraries to do this but they are all written in Objective-C. I'm looking for a Swift alternative.
回答1:
As mentioned in the comments, although its possible to use Objective-C libraries in Swift, I wanted a more pure Swift solution. The existing Apple Reachability class and other third party libraries seemed to be too complicated for me to translate to Swift. I Googled some more and I came across this article which shows a simple method to check for network availability. I set out to translate this to Swift. I hit many snags but thanks to Martin R from StackOverflow, I managed to resolve them and finally get a workable solution in Swift. Here is the code.
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
}
}
For 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)
}
}
This works for both 3G and WiFi connections. I've also uploaded it to my GitHub with a working example.
回答2:
I give you better way...
You must create a class with this code
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
}
}
And then you can check internet connection anywhere in your project using this code:
if Reachability.isConnectedToNetwork() == true {
println("Internet connection OK")
} else {
println("Internet connection FAILED")
}
Very easy!
*This way is based on Vikram Pote answer!
回答3:
For Swift 3.1 (iOS 10.1)
If you want to make the distinction between the network-type (i.e. WiFi or WWAN):
You can use:
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
}
}
Here is the entire Reachability-Class that distinguished between network-types:
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
}
}
}
回答4:
Since sendSynchronousRequest is deprecated, I tried this but 'return Status' was called before the response had finished.
This answer works well though, Check for internet connection with Swift
Here's what I tried anyway:
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
}
}
回答5:
SWIFT 3: Checks for wifi and internet connection:
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)
}
}
USAGE:
if Reachability.isConnectedToNetwork() == true {
print("Connected to the internet")
// Do something
} else {
print("No internet connection")
// Do something
}
回答6:
You can also use below answer.
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
}
})
}
回答7:
SWIFT 3: Check 3G & Wi-Fi connection
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()
}
回答8:
For 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
}
回答9:
Swift 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)
}
来源:https://stackoverflow.com/questions/25398664/check-for-internet-connection-availability-in-swift