Question

我正在iOS中创建一个新的旅行应用程序，此应用程序高度依赖于地图，并将包含两个地图。

当用户拥有强大的网络信号（Apple地图）时，我的第一张地图将会正常工作。

我的第二张地图将在他们不是任何网络或真正低信号时使用（离线   MapBox）。

为什么我在一个应用程序中有两个不同的地图？我的应用程序是一个方向应用程序，因此当用户网络真的很低或没有时，它将转到离线地图MapBox。此外，Apple Maps将与Yelp集成，而不是离线地图MapBox。

所以我的问题：如何在WiFi，4G Lte和3G中检测网络信号。 MapBox Offline Image

Answer 1

我最初的想法是下载一个文件，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，这会测量速度，包括启动连接的延迟。如果您想要考虑初始延迟，也可以在didReceiveResponse中初始化startTime。

完成后，回想起来，我不喜欢花时间或带宽下载对应用程序没有实际好处的东西。因此，作为替代方案，我可能会建议采用更实用的方法：为什么不尝试打开MKMapView并查看完成下载地图需要多长时间？如果失败或者花费的时间超过一定时间，请切换到离线地图。同样，这里存在相当多的可变性（不仅因为网络带宽和延迟，还因为某些地图图像似乎被缓存），因此请确保将kMaximumElapsedTime设置为足够大以处理所有成功连接的合理排列（即，使用低值时不要过于激进）。

为此，请务必将视图控制器设置为delegate的{{1}}。然后你就可以做到：

MKMapView

Answer 2

我相信谷歌搜索会有所帮助。

请注意StackOverflow上的以下线程 -

iOS wifi scan, signal strength

iPhone signal strength

因此，如果不使用私有API，我认为您仍然无法做到这一点。

Answer 3

对于Swift

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)
    }
  }
}

如何检测iOS可达性中的网络信号强度

3 个答案: