如何检测在iOS的可达性网络的信号强度(How to detect Network Signal S

我创建iOS中新的旅行应用程序，这个应用程序是高度依赖于地图和将包括两个地图。

当用户拥有强大的网络信号（苹果地图）我的第一个地图会工作。
当他们不属于任何网络或相当低的信号（离线MapBox）我的第二个地图将被使用。

为什么我在一个应用两个不同的地图？我的应用程序是一个方向应用程序，所以当用户具有非常低的网络或没有它会去离线地图MapBox 。此外，苹果地图将Yelp的整合，而不是离线地图MapBox 。

所以我的问题：我如何检测的WiFi，4G LTE和3G网络信号。

Answer 1:

我最初的想法是一次文件的下载，看看需要多长时间：

@interface ViewController () <NSURLSessionDelegate, NSURLSessionDataDelegate>

@property (nonatomic) CFAbsoluteTime startTime;
@property (nonatomic) CFAbsoluteTime stopTime;
@property (nonatomic) long long bytesReceived;
@property (nonatomic, copy) void (^speedTestCompletionHandler)(CGFloat megabytesPerSecond, NSError *error);

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self testDownloadSpeedWithTimout:5.0 completionHandler:^(CGFloat megabytesPerSecond, NSError *error) {
        NSLog(@"%0.1f; error = %@", megabytesPerSecond, error);
    }];
}

/// Test speed of download
///
/// Test the speed of a connection by downloading some predetermined resource. Alternatively, you could add the
/// URL of what to use for testing the connection as a parameter to this method.
///
/// @param timeout             The maximum amount of time for the request.
/// @param completionHandler   The block to be called when the request finishes (or times out).
///                            The error parameter to this closure indicates whether there was an error downloading
///                            the resource (other than timeout).
///
/// @note                      Note, the timeout parameter doesn't have to be enough to download the entire
///                            resource, but rather just sufficiently long enough to measure the speed of the download.

- (void)testDownloadSpeedWithTimout:(NSTimeInterval)timeout completionHandler:(nonnull void (^)(CGFloat megabytesPerSecond, NSError * _Nullable error))completionHandler {
    NSURL *url = [NSURL URLWithString:@"http://insert.your.site.here/yourfile"];

    self.startTime = CFAbsoluteTimeGetCurrent();
    self.stopTime = self.startTime;
    self.bytesReceived = 0;
    self.speedTestCompletionHandler = completionHandler;

    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration ephemeralSessionConfiguration];
    configuration.timeoutIntervalForResource = timeout;
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
    [[session dataTaskWithURL:url] resume];
}

- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data {
    self.bytesReceived += [data length];
    self.stopTime = CFAbsoluteTimeGetCurrent();
}

- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {
    CFAbsoluteTime elapsed = self.stopTime - self.startTime;
    CGFloat speed = elapsed != 0 ? self.bytesReceived / (CFAbsoluteTimeGetCurrent() - self.startTime) / 1024.0 / 1024.0 : -1;

    // treat timeout as no error (as we're testing speed, not worried about whether we got entire resource or not

    if (error == nil || ([error.domain isEqualToString:NSURLErrorDomain] && error.code == NSURLErrorTimedOut)) {
        self.speedTestCompletionHandler(speed, nil);
    } else {
        self.speedTestCompletionHandler(speed, error);
    }
}

@end

注意，此措施，包括启动连接的延迟速度。你可以或者初始化startTime在didReceiveResponse ，如果你想分解出，最初的延迟。

已经做了，现在回想起来，我不喜欢花时间或带宽下载的东西，有应用程序没有实际的好处。因此，作为替代，我可能会建议一个更为务实的做法：你为什么不只是尝试打开MKMapView ，看看需要多长时间才能完成下载地图？如果失败或者如果花费超过一定时间以上，然后再切换到离线地图。同样，有相当多的可变性的位置（这不仅是因为网络带宽和延迟，而且还因为一些地图图像似乎被缓存），所以一定要设定一个kMaximumElapsedTime足够大，以处理的所有合理的排列成功连接（即，不要使用低值过于激进）。

要做到这一点，只需确保设置您的视图控制器是delegate的的MKMapView 。然后，你可以这样做：

@interface ViewController () <MKMapViewDelegate>
@property (nonatomic, strong) NSDate *startDate;
@end

static CGFloat const kMaximumElapsedTime = 5.0;

@implementation ViewController

// insert the rest of your implementation here

#pragma mark - MKMapViewDelegate methods

- (void)mapViewWillStartLoadingMap:(MKMapView *)mapView {
    NSDate *localStartDate = [NSDate date];
    self.startDate = localStartDate;

    double delayInSeconds = kMaximumElapsedTime;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        // Check to see if either:
        //   (a) start date property is not nil (because if it is, we 
        //       finished map download); and
        //   (b) start date property is the same as the value we set
        //       above, as it's possible this map download is done, but
        //       we're already in the process of downloading the next
        //       map.

        if (self.startDate && self.startDate == localStartDate)
        {
            [[[UIAlertView alloc] initWithTitle:nil
                                        message:[NSString stringWithFormat:@"Map timed out after %.1f", delayInSeconds]
                                       delegate:nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil] show];
        }
    });
}

- (void)mapViewDidFailLoadingMap:(MKMapView *)mapView withError:(NSError *)error {
    self.startDate = nil;

    [[[UIAlertView alloc] initWithTitle:nil
                                message:@"Online map failed"
                               delegate:nil
                      cancelButtonTitle:@"OK"
                      otherButtonTitles:nil] show];
}

- (void)mapViewDidFinishLoadingMap:(MKMapView *)mapView
{
    NSTimeInterval elapsed = [[NSDate date] timeIntervalSinceDate:self.startDate];
    self.startDate = nil;
    self.statusLabel.text = [NSString stringWithFormat:@"%.1f seconds", elapsed];
}

Answer 2:

我相信谷歌搜索会有所帮助。

查找出在StackOverflow-以下螺纹

的iOS的WiFi扫描，信号强度

iPhone的信号强度

所以，我不认为你仍然可以做到这一点，而无需使用专用的API。

Answer 3:

对于斯威夫特

class NetworkSpeedProvider: NSObject {

var startTime = CFAbsoluteTime()
var stopTime = CFAbsoluteTime()
var bytesReceived: CGFloat = 0
var speedTestCompletionHandler: ((_ megabytesPerSecond: CGFloat, _ error: Error?) -> Void)? = nil

func test() {

    testDownloadSpeed(withTimout: 5.0, completionHandler: {(_ megabytesPerSecond: CGFloat, _ error: Error?) -> Void in
        print("%0.1f; error = \(megabytesPerSecond)")
    })
  }
}


extension NetworkSpeedProvider: URLSessionDataDelegate, URLSessionDelegate {


func testDownloadSpeed(withTimout timeout: TimeInterval, completionHandler: @escaping (_ megabytesPerSecond: CGFloat, _ error: Error?) -> Void) {



    // you set any relevant string with any file
    let urlForSpeedTest = URL(string: "https://any.jpg")




    startTime = CFAbsoluteTimeGetCurrent()
    stopTime = startTime
    bytesReceived = 0
    speedTestCompletionHandler = completionHandler
    let configuration = URLSessionConfiguration.ephemeral
    configuration.timeoutIntervalForResource = timeout
    let session = URLSession(configuration: configuration, delegate: self, delegateQueue: nil)

    guard let checkedUrl = urlForSpeedTest else { return }

    session.dataTask(with: checkedUrl).resume()
}

func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
    bytesReceived += CGFloat(data.count)
    stopTime = CFAbsoluteTimeGetCurrent()
}

func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
    let elapsed = (stopTime - startTime) //as? CFAbsoluteTime
    let speed: CGFloat = elapsed != 0 ? bytesReceived / (CGFloat(CFAbsoluteTimeGetCurrent() - startTime)) / 1024.0 / 1024.0 : -1.0
    // treat timeout as no error (as we're testing speed, not worried about whether we got entire resource or not
    if error == nil || ((((error as NSError?)?.domain) == NSURLErrorDomain) && (error as NSError?)?.code == NSURLErrorTimedOut) {
        speedTestCompletionHandler?(speed, nil)
    }
    else {
        speedTestCompletionHandler?(speed, error)
    }
  }
}

文章来源: How to detect Network Signal Strength in iOS Reachability