获取wifi热点

https://stackoverflow.com/questions/31555640/how-to-get-wifi-ssid-in-ios9-after-captivenetwork-is-deprecated-and-calls-for-wi

Register your app as Hotspot helper.

#import <NetworkExtension/NetworkExtension.h>  

NSArray * networkInterfaces = [NEHotspotHelper supportedNetworkInterfaces];  
NSLog(@"Networks %@",networkInterfaces);

UPDATE (Sept. 11th, 2015)

The following Captive Network APIs have been re-enabled in the latest version of iOS 9 instead.

• CNCopySupportedInterfaces
• CNCopyCurrentNetworkInfo

UPDATE (Sept. 16th, 2015)

If you still prefer to use NetworkExtension and Apple gave you permission to add the entitlements, then you can do this to get the wifi information:

for(NEHotspotNetwork *hotspotNetwork in [NEHotspotHelper supportedNetworkInterfaces]) {
    NSString *ssid = hotspotNetwork.SSID;
    NSString *bssid = hotspotNetwork.BSSID;
    BOOL secure = hotspotNetwork.secure;
    BOOL autoJoined = hotspotNetwork.autoJoined;
    double signalStrength = hotspotNetwork.signalStrength;
}

NetworkExtension provides you some extra information as secure, auto joined or the signal strength. And it also allows you to set credential to wifis on background mode, when the user scans wifis around.