reachabilityWithAddress在Objective C编程中不起作用 [英] reachabilityWithAddress is not working in Objective C programming

问题描述

我想用ip检查服务器是否有效，例如， 74.125.71.104（Google的IP）

I want to check a server is live or not with ip, for example, 74.125.71.104 (Google's ip)

//分配一个可达性对象

// allocate a reachability object

`struct sockaddr_in address;
address.sin_len = sizeof(address);
address.sin_family = AF_INET;
address.sin_port = htons(80);
address.sin_addr.s_addr = inet_addr("74.125.71.104");`

Reachability *reach = [Reachability reachabilityWithAddress:&address];

但那些不起作用。

我改为 reachabilityWithHostname ，它正在工作。

推荐答案

请导入 #include< arpa / inet.h>

 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
struct sockaddr_in address;
address.sin_len = sizeof(address);
address.sin_family = AF_INET;
address.sin_port = htons(8080);
address.sin_addr.s_addr = inet_addr("216.58.199.174"); //google ip
self.internetReachability = [Reachability reachabilityWithAddress:&address];
[self.internetReachability startNotifier];
[self updateInterfaceWithReachability:self.internetReachability];

编辑

根据您的评论，不会调用您的可访问性块。我总是使用通知，不太了解可达性块。所以我更喜欢使用以下通知。

As per your comments your reachability blocks are not called. I always use notifications not much aware of reachability blocks. So I prefer using notifications as follow.

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
struct sockaddr_in address;
address.sin_len = sizeof(address);
address.sin_family = AF_INET;
address.sin_port = htons(8080);
address.sin_addr.s_addr = inet_addr("216.58.199.174");
self.internetReachability = [Reachability reachabilityWithAddress:&address];
[self.internetReachability startNotifier];
[self updateInterfaceWithReachability:self.internetReachability];

现在，只要您的互联网状态发生变化，就会触发可更新性实例触发更改方法：）

Now whenever your internet status changes reachabilityChanged method will be triggerred with reachability instance :)

- (void) reachabilityChanged:(NSNotification *)note {
    Reachability* curReach = [note object];
    [self updateInterfaceWithReachability:curReach];
}

最后实现updateInterfaceWithReachability为

Finally implement updateInterfaceWithReachability as

- (void)updateInterfaceWithReachability:(Reachability *)reachability {
   NetworkStatus netStatus = [reachability currentReachabilityStatus];
            switch (netStatus)
            {
                case NotReachable: {
                    //not reachable
                }
                break;
                case ReachableViaWWAN:
                case ReachableViaWiFi:        {
                    //reachable via either 3g or wifi
                }
                break;
            }
}

希望这有帮助。

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