How do I use CaptiveNetwork to get the current WiFi Hotspot Name

I need to get the name of the currently connected Wi-Fi hotspot, e.g. "BT OpenZone"

I have been told it can be done with CaptiveNetwork specifically CNCopyCurrentNetworkInfo

My code so far:

#import <SystemConfiguration/CaptiveNetwork.h>
...

// Get the dictionary containing the captive network infomation
CFDictionaryRef captiveNtwrkDict = CNCopyCurrentNetworkInfo(kCNNetworkInfoKeySSID);

// Get the count of the key value pairs to test if it has worked
int count = CFDictionaryGetCount(captiveNtwrkDict);
NSLog(@"Count of dict:%d",count);

When the code runs on a device in a WiFi hotspot the captiveNtwrkDict is nil.

Has anyone managed to get it working? I cant find much documentation or any example code examples on CaptiveNetworks... any help would be much appreciated.

You need to find out which networks are available, and then pass them into CNCopyCurrentNetworkInfo. For example:

CFArrayRef myArray = CNCopySupportedInterfaces();
CFDictionaryRef myDict = CNCopyCurrentNetworkInfo(CFArrayGetValueAtIndex(myArray, 0));

...and you can then use the kCNNetworkInfoKeySSID on the dictionary you've got back (myDict) to find out the SSID. Don't forget to release/manage memory appropriately.

UPDATE FOR iOS 12, swift 4.2

iOS 12

You must enable Access WiFi Information from capabilities.

Important To use this function in iOS 12 and later, enable the Access WiFi Information capability for your app in Xcode. When you enable this capability, Xcode automatically adds the Access WiFi Information entitlement to your entitlements file and App ID. Documentation link

Swift4.2

public class SSID {
    class func fetchSSIDInfo() -> String {
        var currentSSID = ""
        if let interfaces = CNCopySupportedInterfaces() {
            for i in 0..<CFArrayGetCount(interfaces) {
                let interfaceName: UnsafeRawPointer = CFArrayGetValueAtIndex(interfaces, i)
                let rec = unsafeBitCast(interfaceName, to: AnyObject.self)
                let unsafeInterfaceData = CNCopyCurrentNetworkInfo("\(rec)" as CFString)
                if let interfaceData = unsafeInterfaceData as? [String: AnyObject] {
                    currentSSID = interfaceData["SSID"] as! String
                    let BSSID = interfaceData["BSSID"] as! String
                    let SSIDDATA = interfaceData["SSIDDATA"]
                    debugPrint("ssid=\(currentSSID), BSSID=\(BSSID), SSIDDATA=\(SSIDDATA)")
                }
            }
        }
        return currentSSID
    }
}

UPDATE FOR iOS 10

CNCopySupportedInterfaces is no longer deprecated in iOS 10. (API Reference)

You need to import SystemConfiguration/CaptiveNetwork.h and add SystemConfiguration.framework to your target's Linked Libraries (under build phases).

Here is a code snippet in swift (RikiRiocma's Answer):

import Foundation
import SystemConfiguration.CaptiveNetwork

public class SSID {
    class func fetchSSIDInfo() ->  String {
        var currentSSID = ""
        if let interfaces:CFArray! = CNCopySupportedInterfaces() {
            for i in 0..<CFArrayGetCount(interfaces){
                let interfaceName: UnsafePointer<Void> = CFArrayGetValueAtIndex(interfaces, i)
                let rec = unsafeBitCast(interfaceName, AnyObject.self)
                let unsafeInterfaceData = CNCopyCurrentNetworkInfo("\(rec)")
                if unsafeInterfaceData != nil {
                    let interfaceData = unsafeInterfaceData! as Dictionary!
                    currentSSID = interfaceData["SSID"] as! String
                }
            }
        }
    return currentSSID
    }
}

(Important: CNCopySupportedInterfaces returns nil on simulator.)

For Objective-c, see Esad's answer here and below

+ (NSString *)GetCurrentWifiHotSpotName {    
    NSString *wifiName = nil;
    NSArray *ifs = (__bridge_transfer id)CNCopySupportedInterfaces();
    for (NSString *ifnam in ifs) {
        NSDictionary *info = (__bridge_transfer id)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        if (info[@"SSID"]) {
            wifiName = info[@"SSID"];
        }
    }
    return wifiName;
}

UPDATE FOR iOS 9

As of iOS 9 Captive Network is deprecated*. (source)

*No longer deprecated in iOS 10, see above.

It's recommended you use NEHotspotHelper (source)

You will need to email apple at [email protected] and request entitlements. (source)

Sample Code (Not my code. See Pablo A's answer):

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;
}

Side note: Yup, they deprecated CNCopySupportedInterfaces in iOS 9 and reversed their position in iOS 10. I spoke with an Apple networking engineer and the reversal came after so many people filed Radars and spoke out about the issue on the Apple Developer forums.