检查Internet连接的可用性(iOS) Xcode 8, Swift 3.0

这是一个简单的方法来检查网络可用性，如我们的设备是否连接到任何网络。我已经成功地将其翻译为Swift 3.0，这里是最终的代码。现有的Apple Reachability类和其他第三方库似乎太复杂了，无法翻译到Swift中。 这适用于3G、4G和WiFi连接。 不要忘记在你的项目构建器中添加“SystemConfiguration.framework”。

//Create new swift class file Reachability in your project.
import SystemConfiguration
public class InternetReachability {

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
  }
}

// Check network connectivity from anywhere in project by using this code.
 if InternetReachability.isConnectedToNetwork() == true {
         print("Internet connection OK")
  } else {
         print("Internet connection FAILED")
  }

创建一个AFNetworkReachabilityManager对象，并使用以下代码跟踪网络连通性

self.reachabilityManager = [AFNetworkReachabilityManager managerForDomain:@"yourDomain"];
[self.reachabilityManager startMonitoring];
[self.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case AFNetworkReachabilityStatusReachableViaWWAN:
            case AFNetworkReachabilityStatusReachableViaWiFi:
                break;
            case AFNetworkReachabilityStatusNotReachable:
                break;
            default:
                break;
        }
    }];

步骤1:在项目中添加Reachability类。 步骤2:导入Reachability类 步骤3:创建下面的函数 - (BOOL)checkNetConnection { self.internetReachability =[可达性reachabilityForInternetConnection]; [self.internetReachability startNotifier]; NetworkStatus netStatus = [self.internetReachability currentReachabilityStatus]; switch (netStatus) { 案例NotReachable: ｛ 返回NO; } 案例ReachableViaWWAN: ｛ 返回YES; } 案例ReachableViaWiFi: ｛ 返回YES; } } } 步骤4:调用函数如下所示: 如果(![self checkNetConnection]) { [GlobalFunctions showAlert: @”“ 信息:@“请连接到互联网!” canBtntitle:零 otherBtnTitle: @“Ok”); 返回; } 其他的 ｛ 日志。V(“internet is connected”，“ok”); }

这里有一个非常简单的答案:

NSURL *scriptUrl = [NSURL URLWithString:@"http://www.google.com/m"];
NSData *data = [NSData dataWithContentsOfURL:scriptUrl];
if (data)
    NSLog(@"Device is connected to the Internet");
else
    NSLog(@"Device is not connected to the Internet");

URL应该指向一个非常小的网站。我在这里使用谷歌的移动网站，但如果我有一个可靠的网络服务器，我会上传一个只有一个字符的小文件，以获得最快的速度。

如果检查设备是否以某种方式连接到互联网是你想做的一切，我绝对推荐使用这个简单的解决方案。如果您需要知道用户是如何连接的，那么使用可达性是正确的方法。

小心:这将短暂地阻塞你的线程，而它加载网站。对我来说，这不是问题，但你应该考虑一下(感谢Brad指出了这一点)。

Swift 3 / Swift 4

您必须首先导入

import SystemConfiguration

您可以通过以下方法检查Internet连接。

func isConnectedToNetwork() -> 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.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
    let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
    return (isReachable && !needsConnection)
}

使用Apple的Reachability代码，我创建了一个函数，可以正确地检查这一点，而无需包含任何类。

在你的项目中包含SystemConfiguration.framework。

进行一些导入:

#import <sys/socket.h>
#import <netinet/in.h>
#import <SystemConfiguration/SystemConfiguration.h>

现在只需调用这个函数:

/*
Connectivity testing code pulled from Apple's Reachability Example: https://developer.apple.com/library/content/samplecode/Reachability
 */
+(BOOL)hasConnectivity {
    struct sockaddr_in zeroAddress;
    bzero(&zeroAddress, sizeof(zeroAddress));
    zeroAddress.sin_len = sizeof(zeroAddress);
    zeroAddress.sin_family = AF_INET;

    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)&zeroAddress);
    if (reachability != NULL) {
        //NetworkStatus retVal = NotReachable;
        SCNetworkReachabilityFlags flags;
        if (SCNetworkReachabilityGetFlags(reachability, &flags)) {
            if ((flags & kSCNetworkReachabilityFlagsReachable) == 0)
            {
                // If target host is not reachable
                return NO;
            }

            if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0)
            {
                // If target host is reachable and no connection is required
                //  then we'll assume (for now) that your on Wi-Fi
                return YES;
            }


            if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand ) != 0) ||
                 (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0))
            {
                // ... and the connection is on-demand (or on-traffic) if the
                //     calling application is using the CFSocketStream or higher APIs.

                if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0)
                {
                    // ... and no [user] intervention is needed
                    return YES;
                }
            }

            if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN)
            {
                // ... but WWAN connections are OK if the calling application
                //     is using the CFNetwork (CFSocketStream?) APIs.
                return YES;
            }
        }
    }

    return NO;
}

这是为你测试的iOS 5。