ios - 如何在iOS或macOS上检查活动的Internet连接？(How to check for an active Internet connection on iOS or macOS?)

Question

I would like to check to see if I have an Internet connection on iOS using the Cocoa Touch libraries or on macOS using the Cocoa libraries.

(我想检查一下我是否在使用Cocoa Touch库的iOS上或在使用Cocoa库的macOS上建立了Internet连接。)

I came up with a way to do this using an NSURL .

(我想出了一种使用NSURL做到这一点的方法。)

The way I did it seems a bit unreliable (because even Google could one day be down and relying on a third party seems bad), and while I could check to see for a response from some other websites if Google didn't respond, it does seem wasteful and an unnecessary overhead on my application.

(我这样做的方式似乎有点不可靠（因为即使Google可能有一天会倒闭，依赖第三方也似乎很糟糕），而且我可以检查一下是否有其他网站的响应（如果Google没有响应），确实看起来很浪费，而且对我的应用程序来说也没有不必要的开销。)

- (BOOL) connectedToInternet
{
    NSString *URLString = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://www.google.com"]];
    return ( URLString != NULL ) ? YES : NO;
}

Is what I have done bad, (not to mention stringWithContentsOfURL is deprecated in iOS 3.0 and macOS 10.4) and if so, what is a better way to accomplish this?

(我做的不stringWithContentsOfURL （更不用说在iOS 3.0和macOS 10.4中不推荐使用stringWithContentsOfURL ），如果是的话，有什么更好的方法来做到这一点？)

  ask by Brock Woolf translate from so

Answer 1

Important : This check should always be performed asynchronously.

(重要提示 ：此检查应始终异步执行。)

The majority of answers below are synchronous so be careful otherwise you'll freeze up your app.

(以下大多数答案是同步的，因此请小心，否则将冻结您的应用程序。)

---

Swift (迅速)

1) Install via CocoaPods or Carthage: https://github.com/ashleymills/Reachability.swift

(1）通过CocoaPods或迦太基安装： https : //github.com/ashleymills/Reachability.swift)

2) Test reachability via closures

(2）通过闭包测试可达性)

let reachability = Reachability()!

reachability.whenReachable = { reachability in
    if reachability.connection == .wifi {
        print("Reachable via WiFi")
    } else {
        print("Reachable via Cellular")
    }
}

reachability.whenUnreachable = { _ in
    print("Not reachable")
}

do {
    try reachability.startNotifier()
} catch {
    print("Unable to start notifier")
}

---

Objective-C (物镜)

1) Add SystemConfiguration framework to the project but don't worry about including it anywhere

(1）将SystemConfiguration框架添加到项目中，但不必担心将其包含在任何地方)

2) Add Tony Million's version of Reachability.h and Reachability.m to the project (found here: https://github.com/tonymillion/Reachability )

(2）将Tony Million的Reachability.h和Reachability.m版本添加到项目中（可在此处找到： https : //github.com/tonymillion/Reachability ）)

3) Update the interface section

(3）更新界面部分)

#import "Reachability.h"

// Add this to the interface in the .m file of your view controller
@interface MyViewController ()
{
    Reachability *internetReachableFoo;
}
@end

4) Then implement this method in the .m file of your view controller which you can call

(4）然后在您可以调用的视图控制器的.m文件中实现此方法)

// Checks if we have an internet connection or not
- (void)testInternetConnection
{   
    internetReachableFoo = [Reachability reachabilityWithHostname:@"www.google.com"];

    // Internet is reachable
    internetReachableFoo.reachableBlock = ^(Reachability*reach)
    {
        // Update the UI on the main thread
        dispatch_async(dispatch_get_main_queue(), ^{
            NSLog(@"Yayyy, we have the interwebs!");
        });
    };

    // Internet is not reachable
    internetReachableFoo.unreachableBlock = ^(Reachability*reach)
    {
        // Update the UI on the main thread
        dispatch_async(dispatch_get_main_queue(), ^{
            NSLog(@"Someone broke the internet :(");
        });
    };

    [internetReachableFoo startNotifier];
}

Important Note: The Reachability class is one of the most used classes in projects so you might run into naming conflicts with other projects.

(重要说明： Reachability类是项目中最常用的类之一，因此您可能会遇到与其他项目的命名冲突。)

If this happens, you'll have to rename one of the pairs of Reachability.h and Reachability.m files to something else to resolve the issue.

(如果发生这种情况，则必须将Reachability.h和Reachability.m文件对中的一个重命名为其他名称才能解决此问题。)

Note: The domain you use doesn't matter.

(注意：您使用的域无关紧要。)

It's just testing for a gateway to any domain.

(它只是测试通往任何域的网关。)