1. 引入头，#import <SystemConfiguration/CaptiveNetwork.h>

2. 获取SSID info

+ (id)fetchSSIDInfo

{

    NSArray *ifs = (__bridge id)CNCopySupportedInterfaces();

    NSLog(@"%s: Supported interfaces: %@", __func__, ifs);

    id info = nil;

    for (NSString *ifnam in ifs) {

        info = (__bridge id)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);

        if (info && [info count]) {

            break;

        }

    }

    return info;

}

3. 调用 

    NSDictionary *ifs = [AppDelegate fetchSSIDInfo];

    NSString *ssid = [[ifs objectForKey:@"SSID"] lowercaseString];

    NSLog(@"ssid：%@",ssid);

4.此框架介绍可参照此link http://bobffin.wordpress.com/2013/12/30/ios-captivenetwork-api-的用法/   

wifi current SSID