如何檢查本地WiFi網絡中的設備是否已使用其IP地址連接？

Question

我在我的iOS應用程序中使用了MMLANScanner庫。 它向我顯示了連接到本地WiFi路由器的所有設備以及以前連接到本地WiFi路由器的設備。

我如何確定當前獲取的設備IP是否已連接到本地WiFi路由器？

Answer 1

您可以使用蘋果的“可達性”，也可以使用簡單的ping。 以下是兩個項目的鏈接。

[簡單Ping] https://developer.apple.com/library/content/samplecode/SimplePing/Introduction/Intro.html#//apple_ref/doc/uid/DTS10000716-Intro-DontLinkElementID_2

[可達到性] https://developer.apple.com/library/content/samplecode/Reachability/Introduction/Intro.html

Answer 2

使用Apple的Reachability示例，這里是一些代碼來檢查設備的連接性。

#import "Reachability.h"

@interface ViewController : UIViewController 
{
     BOOL isInternetConnectionAvailable;
}
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
//--Reachability--
    /*
     Observe the kNetworkReachabilityChangedNotification. When that notification is posted, the method reachabilityChanged will be called.
     */
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];

    self.internetReachability = [Reachability reachabilityForInternetConnection];
    [self.internetReachability startNotifier];
    [self updateInterfaceWithReachability:self.internetReachability];
    //--+--//


}
#pragma mark Reachability
/*!
 * Called by Reachability whenever status changes.
 */
- (void) reachabilityChanged:(NSNotification *)note
{
    Reachability* curReach = [note object];
    NSParameterAssert([curReach isKindOfClass:[Reachability class]]);
    [self updateInterfaceWithReachability:curReach];
}


- (void)updateInterfaceWithReachability:(Reachability *)reachability
{

    if (reachability == self.internetReachability)
    {
        NetworkStatus netStatus = [reachability currentReachabilityStatus];
        BOOL connectionRequired = [reachability connectionRequired];
        NSString* statusString = @"";

        //
        UIAlertController * connectivityAlert = [UIAlertController alertControllerWithTitle:@"Connectivity" message:[NSString stringWithFormat:@"Status:%@",statusString] preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction * ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil];
        [connectivityAlert addAction:ok];
        //

        switch (netStatus)
        {
            case NotReachable:        {
                statusString = NSLocalizedString(@"Access Not Available", @"Text field text for access is not available");
                /*
                 Minor interface detail- connectionRequired may return YES even when the host is unreachable. We cover that up here...
                 */
                connectionRequired = NO;

                connectivityAlert.message = [NSString stringWithFormat:@"Status:%@",statusString];
                [self presentViewController:connectivityAlert animated:YES completion:nil];
                isInternetConnectionAvailable = NO;
                break;
            }

            case ReachableViaWWAN:        {
                statusString = NSLocalizedString(@"Reachable WWAN", @"");

                connectivityAlert.message = [NSString stringWithFormat:@"Status:%@",statusString];

                isInternetConnectionAvailable = YES;
                break;
            }
            case ReachableViaWiFi:        {
                statusString= NSLocalizedString(@"Reachable WiFi", @"");

                connectivityAlert.message = [NSString stringWithFormat:@"Status:%@",statusString];

                isInternetConnectionAvailable = YES;
                break;
            }
        }

        if (connectionRequired)
        {
            NSString *connectionRequiredFormatString = NSLocalizedString(@"%@, Connection Required", @"Concatenation of status string with connection requirement");
            statusString= [NSString stringWithFormat:connectionRequiredFormatString, statusString];

            connectivityAlert.message = [NSString stringWithFormat:@"Status:%@",statusString];
            isInternetConnectionAvailable = NO;
            [self presentViewController:connectivityAlert animated:YES completion:nil];
        }
    }

}
@end