如何检查 iOS 设备上的互联网连接？

Question

我想知道如何检查用户是否通过 WIFI 或蜂窝数据 3G 或 4G 连接到互联网。

我也不想检查网站是否可以访问，我想检查设备上是否有互联网。我试图浏览互联网，我所看到的只是他们使用 Rechability class.

检查网站是否可以访问

我想在用户打开我的应用程序时检查他是否有互联网。

我正在使用 Xcode6 和 Objective-C。

Answer 1

使用此代码并导入 Reachability.h 文件

if ([[Reachability reachabilityForInternetConnection]currentReachabilityStatus]==NotReachable)
    {
         //connection unavailable
    }
    else
    {
         //connection available
    }

Answer 2

希望这可以帮助您仅在 Wifi 模式下联网：

Utils.h

 #import <Foundation/Foundation.h>
 @interface Utils : NSObject

 +(BOOL)isNetworkAvailable;

 @end

utils.m

 + (BOOL)isNetworkAvailable
{
      CFNetDiagnosticRef dReference;
      dReference = CFNetDiagnosticCreateWithURL (NULL, (__bridge CFURLRef)[NSURL URLWithString:@"www.apple.com"]);

      CFNetDiagnosticStatus status;
      status = CFNetDiagnosticCopyNetworkStatusPassively (dReference, NULL);

      CFRelease (dReference);

      if ( status == kCFNetDiagnosticConnectionUp )
      {
          NSLog (@"Connection is Available");
          return YES;
      }
      else
      {
          NSLog (@"Connection is down");
          return NO;
      }
    }

//现在在需要的地方使用这个class

- (IBAction)MemberSubmitAction:(id)sender {
   if([Utils isNetworkAvailable] ==YES){

      NSlog(@"Network Connection available");
   }

 }

Answer 3

试试这个

检查此 link 的可达性文件

Reachability

将此文件导入您的 .m 中，然后编写代码

//这是检查网络连接

  BOOL hasInternetConnection = [[Reachability reachabilityForInternetConnection] isReachable];
    if (hasInternetConnection) {
               // your code
    }

希望对您有所帮助。

Answer 4

首次下载可达性类来自此 Link:
Rechability from Github

在AppDelegate.h中添加可达性实例

@property (nonatomic) Reachability *hostReachability;
@property (nonatomic) Reachability *internetReachability;
@property (nonatomic) Reachability *wifiReachability;

在您的 AppDelegate 中导入 Reachability，然后将此代码复制并粘贴到您的 Appdelegate.m

- (id)init
{
    self = [super init];
    if (self != nil)
    {
        //[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
        NSString *remoteHostName = @"www.google.com";
        self.hostReachability = [Reachability reachabilityWithHostName:remoteHostName];
        [self.hostReachability startNotifier];

        self.internetReachability = [Reachability reachabilityForInternetConnection];
        [self.internetReachability startNotifier];

        self.wifiReachability = [Reachability reachabilityForLocalWiFi];
        [self.wifiReachability startNotifier];
    }
    return self;
}

将此方法添加到您的 Common Class。

/*================================================================================================
 Check Internet Rechability
 =================================================================================================*/
+(BOOL)checkIfInternetIsAvailable
{
    BOOL reachable = NO;
    NetworkStatus netStatus = [APP_DELEGATE1.internetReachability currentReachabilityStatus];
    if(netStatus == ReachableViaWWAN || netStatus == ReachableViaWiFi)
    {
        reachable = YES;
    }
    else
    {
        reachable = NO;
    }
    return reachable;
}

注意APP_DELEGATE1是AppDelegate的一个实例

/* AppDelegate object */
#define APP_DELEGATE1 ((AppDelegate*)[[UIApplication sharedApplication] delegate])

您可以使用此方法在应用中的任何位置检查互联网连接。

Answer 5

很简单，您可以使用以下方法检查互联网连接。

-(BOOL)IsConnectionAvailable
{
    Reachability *reachability = [Reachability reachabilityForInternetConnection];

    NetworkStatus networkStatus = [reachability currentReachabilityStatus];

    return !(networkStatus == NotReachable);    
}

Answer 6

Reachability* reachability = [Reachability reachabilityWithHostName:@"www.google.com"];
NetworkStatus internetStatus = [reachability currentReachabilityStatus];

 if(remoteHostStatus == ReachableViaWWAN || remoteHostStatus == ReachableViaWiFi)

{


     //my web-dependent code
}
else {
    //there-is-no-connection warning
}

Answer 7

试试这个来检查互联网连接与否

NSURL *url = [NSURL URLWithString:@"http://www.appleiphonecell.com/"];
NSMutableURLRequest *headRequest = [NSMutableURLRequest requestWithURL:url];
headRequest.HTTPMethod = @"HEAD";

NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration ephemeralSessionConfiguration];
defaultConfigObject.timeoutIntervalForResource = 10.0;
defaultConfigObject.requestCachePolicy = NSURLRequestReloadIgnoringLocalAndRemoteCacheData;

NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration:defaultConfigObject delegate:nil delegateQueue: [NSOperationQueue mainQueue]];

NSURLSessionDataTask *dataTask = [defaultSession dataTaskWithRequest:headRequest
                                                   completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
                                  {
                                      if (!error && response)
                                      {
                                          block([(NSHTTPURLResponse *)response statusCode] == 200);
                                      }else{
                                          block(FALSE);
                                      }
                                  }];
[dataTask resume];

Answer 8

'Reachability' 不起作用，因为它不会检测主机是否有响应。它只会检查客户端是否可以向主机发送数据包。因此，即使您连接到 WiFi 网络并且 WiFi 的互联网已关闭或服务器已关闭，您也会获得 "YES" 的可达性。

更好的方法是尝试 HTTP 请求并验证响应。

示例如下：

NSURL *pageToLoadUrl = [[NSURL alloc] initWithString:@"https://www.google.com/"];
NSMutableURLRequest *pageRequest = [NSMutableURLRequest requestWithURL:pageToLoadUrl];
[pageRequest setTimeoutInterval:2.0];
AFHTTPRequestOperation *pageOperation = [[AFHTTPRequestOperation alloc] initWithRequest:pageRequest];
AFRememberingSecurityPolicy *policy = [AFRememberingSecurityPolicy policyWithPinningMode:AFSSLPinningModeNone];
[policy setDelegate:self];
currentPageOperation.securityPolicy = policy;
if (self.ignoreSSLCertificate) {
    NSLog(@"Warning - ignoring invalid certificates");
    currentPageOperation.securityPolicy.allowInvalidCertificates = YES;
}
[pageOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
    internetActive = YES;
} failure:^(AFHTTPRequestOperation *operation, NSError *error){
    NSLog(@"Error:------>%@", [error description]);
    internetActive = NO;
}];
[pageOperation start];

唯一的问题是 "internetActive" 的更新延迟到上述代码中提到的超时时间。您可以在回调中编写代码以对状态进行操作。

Answer 9

使用Alamofire library:

let reachabilityManager = NetworkReachabilityManager()
let isReachable = reachabilityManager.isReachable

if (isReachable) {
    //Has internet
}else{
    //No internet
}

Answer 10

Swift 4.0 和 AlamoFire 的更新答案：

我在9月18日发布的答案是错误的，它只检测是否连接到网络，而不是互联网。这是使用 AlamoFire 的正确解决方案：

1) 创建自定义 Reachability Observer class:

import Alamofire

class ReachabilityObserver {

    fileprivate let reachabilityManager = NetworkReachabilityManager()
    fileprivate var reachabilityStatus: NetworkReachabilityManager.NetworkReachabilityStatus = .unknown

    var isOnline: Bool {
        if (reachabilityStatus == .unknown || reachabilityStatus == .notReachable){
            return false
        }else{
            return true
        }
    }

    static let sharedInstance = ReachabilityObserver()
    fileprivate init () {
        reachabilityManager?.listener = {
            [weak self] status in

            self?.reachabilityStatus = status
            NotificationCenter.default.post(
                name: NSNotification.Name(rawValue: ClickUpConstants.ReachabilityStateChanged),
                object: nil)
        }
        reachabilityManager?.startListening()
    }
}

2) 在应用程序启动时初始化

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
     _ = ReachabilityObserver.sharedInstance
     return true
}

3) 在您的应用中的任何地方使用它来检测是否在线，例如在视图中是否加载，或何时发生操作

if (ReachabilityObserver.sharedInstance.isOnline){
    //User is online
}else{
    //User is not online
}

如何检查 iOS 设备上的互联网连接？

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