首先:在framework中添加CFNetwork.framework

代码:ViewController.m

#import "Reachability.h"

- (void)viewWillAppear:(BOOL)animated
{
    Reachability *r = [Reachability reachabilityWithHostName:@"www.google.com"];
    NetworkStatus internetStatus = [r currentReachabilityStatus];

    if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN))
    {
        /// Create an alert if connection doesn't work
        UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"No Internet Connection"   message:NSLocalizedString(@"InternetMessage", nil)delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
        [myAlert show];
        [myAlert release];
    }
    else
    {
         NSLog(@"INTERNET IS CONNECT");
    }
}

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”); }

苹果提供了一个示例应用程序，它正是这样做的:

可达性

对于我的iOS项目，我建议使用

可达性类

Swift声明。对我来说，它工作得很好

Wi-Fi和蜂窝数据

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(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 = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
            return false
        }

        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
        let ret = (isReachable && !needsConnection)
        return ret
    }
}

使用条件语句，

if Reachability.isConnectedToNetwork() {
    // Enter your code here
}
}
else {
    print("NO Internet connection")
}

这个类在几乎所有应用程序使用Internet连接的情况下都很有用。 例如，如果条件为真，就可以调用API或执行任务。

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。

很简单的…试试下面这些步骤:

步骤1:将SystemConfiguration框架添加到项目中。

步骤2:将以下代码导入到头文件中。

#import <SystemConfiguration/SystemConfiguration.h>

第三步:使用以下方法

类型1: - (BOOL) currentNetworkStatus { [UIApplication sharedApplication].networkActivityIndicatorVisible = NO; BOOL连接; BOOL与; Const char *host = "www.apple.com"; SCNetworkReachabilityRef reachabilityreachabilitycreatewithname (NULL, host); SCNetworkReachabilityFlags旗帜; connected = SCNetworkReachabilityGetFlags(可达性，&flags); isConnected = NO; isConnected = connected && (flags & kSCNetworkFlagsReachable) && !(flags & kSCNetworkFlagsConnectionRequired); CFRelease(可达性); 返回与; ｝

类型2: 导入头文件:# Import "Reachability.h" (保龄球)currentNetworkStatus ｛ 可达性*可达性=[互联网连接的可达性]; NetworkStatus NetworkStatus =[可达性currentReachabilityStatus]; 返回networkStatus !=不可访问; ｝

第四步:使用方法:

- (void)CheckInternet
{
    BOOL network = [self currentNetworkStatus];
    if (network)
    {
        NSLog(@"Network Available");
    }
    else
    {
        NSLog(@"No Network Available");
    }
}