iOS 获取已连接的wifi信息

转：http://blog.csdn.net/marujunyy/article/details/16843173

首先需要   #import <SystemConfiguration/CaptiveNetwork.h>

+ (id)fetchSSIDInfo
{
    NSArray *ifs = (id)CNCopySupportedInterfaces();
    NSLog(@"%s: Supported interfaces: %@", __func__, ifs);
    id info = nil;
    for (NSString *ifnam in ifs) {
        info = (id)CNCopyCurrentNetworkInfo((CFStringRef)ifnam);
        NSLog(@"%@ => %@", ifnam, info);
        if (info && [info count]) { break; }
        [info release];
    }
    [ifs release];
    return [info autorelease];
}

ARC 版本：

+ (id)fetchSSIDInfo {
    NSArray *ifs = (__bridge_transfer id)CNCopySupportedInterfaces();
    NSLog(@"%s: Supported interfaces: %@", __func__, ifs);
    id info = nil;
    for (NSString *ifnam in ifs) {
        info = (__bridge_transfer id)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        NSLog(@"%@ => %@", ifnam, info);
        if (info && [info count]) { break; }
    }
    return info;
}