15

我是 iOS 开发的新手，正在努力让reachability.h 类工作。这是我的视图控制器代码：

- (void)viewWillAppear:(BOOL)animated
{
    [[NSNotificationCenter defaultCenter]
     addObserver:self 
     selector:@selector(checkNetworkStatus:) 
     name:kReachabilityChangedNotification 
     object:nil];

    internetReachable = [Reachability reachabilityForInternetConnection];
    [internetReachable startNotifier];
}

- (void)checkNetworkStatus:(NSNotification *)notice {
    NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
    NSLog(@"Network status: %i", internetStatus);
}

看起来不错，但在运行应用程序并切换到该视图时，xcode 控制台中没有出现任何内容。

我正在使用可达性 2.2 和 iOS 4.2。

有什么明显的我做错了吗？

4

7 回答 7

55

已编辑：如果您想在执行某些代码之前检查可访问性，您应该使用

Reachability *reachability = [Reachability reachabilityForInternetConnection];    
NetworkStatus internetStatus = [reachability currentReachabilityStatus];
if (internetStatus != NotReachable) {
    //my web-dependent code
}
else {
    //there-is-no-connection warning
}

您还可以在某处（即在viewDidLoad）添加可达性观察者：

Reachability *reachabilityInfo;
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(myReachabilityDidChangedMethod)
                                             name:kReachabilityChangedNotification
                                           object:reachabilityInfo];

[[NSNotificationCenter defaultCenter] removeObserver:self];当您不再需要可达性检测（即在dealloc方法中）时，不要忘记调用。

于 2011-03-04T15:28:11.593 回答
6

这是我的做法。我有一个在我的 init 方法中设置的实例变量：

_reachability = [[APReachability reachabilityForInternetConnection] retain];

当我需要查询网络状态时，我会：

NetworkStatus networkStatus = [_reachability currentReachabilityStatus];
if (networkStatus != NotReachable) {
    // Network related code
}
else {
    // No network code
}

如果你关心wifi等，网络状态可以是：

    NotReachable // No network
    ReachableViaWiFi // Reachable via Wifi
    ReachableViaWWAN // Reachable via cellular
于 2011-03-04T19:03:25.143 回答
4

更新：2013 年 11 月 4 日

在 iOS7 上使用可达性 3.0 版本

在@NR4TR 和@codecaffeine 的答案之上构建：

有 5 种方法可以做到这一点（未编译:)

#include <ifaddrs.h>
#include <arpa/inet.h>

//1 - Is www.apple.com reachable?
Reachability *rHostName = [Reachability reachabilityWithHostName:@"www.apple.com"];
NetworkStatus s1 = [rHostName currentReachabilityStatus];

//2 - Is local wifi router or access point reachable?
Reachability *rLocalWiFi = [Reachability reachabilityForLocalWiFi];
NetworkStatus s2 = [rLocalWiFi currentReachabilityStatus];

//3 - Is my access point connected to a router and the router connected to the internet?
Reachability *rConnection = [Reachability reachabilityForInternetConnection];
NetworkStatus s3 = [rConnection currentReachabilityStatus];

//4  IPv4 standard addresses checking instead of host to avoid dns lookup step
struct sockaddr_in saIPv4;
inet_pton(AF_INET, "74.125.239.51", &(saIPv4.sin_addr));
saIPv4.sin_len = sizeof(saIPv4);
saIPv4.sin_family = AF_INET;
Reachability *rIPv4 = [Reachability reachabilityWithAddress:&saIPv4];
NetworkStatus s4 = [rIPv4 currentReachabilityStatus];

//5  IPv6 addresses checking instead of host to avoid dns lookup step
struct sockaddr_in saIPv6;
inet_pton(AF_INET, "2607:f8b0:4010:801::1014", &(saIPv6.sin_addr));
saIPv6.sin_len = sizeof(saIPv6);
saIPv6.sin_family = AF_INET;
Reachability *rIPv6 = [Reachability reachabilityWithAddress:&saIPv6];
NetworkStatus s5 = [rIPv6 currentReachabilityStatus];

处理状态相同

if (ReachableViaWiFi == s1)
    return @"WiFi"; //@"WLAN"

if (ReachableViaWWAN == s1)
    return @"Cellular"; //@"WWAN"

return @"None";
于 2013-11-04T08:25:26.060 回答
3

按照这个链接，它有非常有用的源代码和步骤 https://github.com/tonymillion/Reachability。这为您提供了有关如何在 Reachability 中使用不同方法进行游戏的信息。

添加 system.configuration.framewok，并将 Reachability.m 和 Reachability.h 文件添加到您的项目中。使用后有类似的方法

+(instancetype)reachabilityWithHostName:(NSString*)hostname;
+(instancetype)reachabilityForInternetConnection;
+(instancetype)reachabilityWithAddress:(void *)hostAddress;
+(instancetype)reachabilityForLocalWiFi;

示例片段：

- (void)CheckConnection
{


    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(reachabilityChanged:) 
                                                 name:kReachabilityChangedNotification 
                                               object:nil];


    Reachability * reach = [Reachability reachabilityWithHostname:@"www.google.com"];

    reach.reachableBlock = ^(Reachability * reachability)
    {
        dispatch_async(dispatch_get_main_queue(), ^{
            _blockLabel.stringValue = @"Block Says Reachable";
        });
    };

    reach.unreachableBlock = ^(Reachability * reachability)
    {
        dispatch_async(dispatch_get_main_queue(), ^{
            _blockLabel.stringValue = @"Block Says Unreachable";
        });
    };

    [reach startNotifier];
}

希望这可以帮助

于 2016-06-10T10:36:31.707 回答
0

只需导入可达性类，然后

-(BOOL) connectedToNetwork
 {
const char *host_name = "www.google.com";
  BOOL _isDataSourceAvailable = NO;
Boolean success;
SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL,host_name);
SCNetworkReachabilityFlags flags;
success = SCNetworkReachabilityGetFlags(reachability, &flags);
_isDataSourceAvailable = success &&
(flags & kSCNetworkFlagsReachable) &&
!(flags & kSCNetworkFlagsConnectionRequired);

CFRelease(reachability);

return _isDataSourceAvailable;
}
于 2013-11-28T12:25:54.587 回答
0

最简单的方法（一旦你为你的项目添加了可达性）：

Reachability *reachability = [Reachability reachabilityForInternetConnection];
if (reachability.isReachable) {
    NSLog(@"We have internet!");
} else {
    NSLog(@"No internet!");
}
于 2017-08-09T16:07:49.470 回答
0

请参考以下代码进行检查Internet Connectivity：

struct sockaddr_in zeroAddress;
bzero(&zeroAddress, sizeof(zeroAddress));
zeroAddress.sin_len = sizeof(zeroAddress);
zeroAddress.sin_family = AF_INET;
// Recover reachability flags
SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr*)&zeroAddress);
SCNetworkReachabilityFlags flags;
BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);
CFRelease(defaultRouteReachability);
if (!didRetrieveFlags) {
    return 0;
}
BOOL isReachable = flags & kSCNetworkFlagsReachable;
BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;

BOOL nonWiFi = flags & kSCNetworkReachabilityFlagsTransientConnection;
NSURL *testURL = [NSURL URLWithString:@"http://www.google.com/"];
NSURLRequest *testRequest = [NSURLRequest requestWithURL:testURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:20.0];

NSURLResponse *response = nil;
NSError *error = nil;

NSData *connectiondata = [NSURLConnection sendSynchronousRequest:testRequest
returningResponse:&response

BOOL connection=NO;

if ([connectiondata length] > 0 &&
error == nil){
    NSLog(@"Connection present” );
    connection=YES;
} else {
    NSLog(@"No Connection" );
    connection=NO;
}

return ((isReachable && !needsConnection) || nonWiFi) ? (connection ? YES : NO) : NO;
于 2016-03-01T10:22:11.263 回答