1.获取Wifi相关信息

• 一般我们常用Wifi信息有Wifi的名称：SSID，还有Wifi的MAC地址：BSSID
• iOS12后，需要在Capabilities中，激活Access WiFi Information项
• iOS13后，需要申请定位权限

#import <SystemConfiguration/CaptiveNetwork.h>
/** 获取当前Wifi名字 */
- Objc
+ (NSString *)currentWiFiName{
    NSArray *ifs = (__bridge_transfer id)CNCopySupportedInterfaces();
    id info = nil;
    for (NSString *ifnam in ifs) {
        info = (__bridge_transfer id)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
        if (info && [info count]) { break; }
    }
    return info[@"SSID"];
    //info[@"BSSID"];
    //info[@"SSIDDATA"];
}

此处切记如果不是使用 __bridge_transfer id转换 记得要手动调用CFRelease，否则会内存泄漏

• Swift

import SystemConfiguration.CaptiveNetwork

struct WifiTool {
    static var currentSSID: String? {
        guard let wifiInterfaces = CNCopySupportedInterfaces() else { return nil }
        let interfaceArr = CFBridgingRetain(wifiInterfaces) as! Array<String>
        if interfaceArr.count > 0 {
            let interfaceName = interfaceArr[0] as CFString
            let ussafeInterfaceData = CNCopyCurrentNetworkInfo(interfaceName)
            if (ussafeInterfaceData != nil) {
                let interfaceData = ussafeInterfaceData as! Dictionary<String, Any>
                return interfaceData["SSID"] as? String
            }
        }
        return nil 
    };
}

2.Wifi是否就绪

• 我们可能有过这种经验，输完wifi密码后，Wifi名字前还在打圈圈，过完一段时间后状态栏上才有Wifi标识
• 手机连上Wifi后，需要一定时间才能就绪

+ (BOOL)wifiIsReady {
    BOOL ret = YES;
    struct ifaddrs * first_ifaddr, * current_ifaddr;
    NSMutableArray * activeInterfaceNames = [NSMutableArray array];
    getifaddrs( &first_ifaddr );
    current_ifaddr = first_ifaddr;
    while( current_ifaddr != NULL ) {
        if( current_ifaddr->ifa_addr->sa_family == 0x02 ) {
            [activeInterfaceNames addObject:[NSString stringWithFormat:@"%s", current_ifaddr->ifa_name]];
        }
        current_ifaddr = current_ifaddr->ifa_next;
    }
    ret = [activeInterfaceNames containsObject:@"en0"] || [activeInterfaceNames containsObject:@"en1"];
    return ret;
}

3.获取当前Wifi的网关地址

#import <arpa/inet.h>
#import <netinet/in.h>
#import <ifaddrs.h>

- (NSString *)getGatewayIpForCurrentWiFi {
    
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        while(temp_addr != NULL) {
        /*/
         int i=255;
         while((i--)>0)
         //*/
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                // Check if interface is en0 which is the wifi connection on the iPhone
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"])
                {
                    // Get NSString from C String //ifa_addr
                    //ifa->ifa_dstaddr is the broadcast address, which explains the "255's"
                    //                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
                    
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    
                    //routerIP----192.168.0.255 广播地址
                    NSLog(@"broadcast address--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)]);
                    //--192.168.0.100 本机地址
                    NSLog(@"local device ip--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)]);
                    //--255.255.255.0 子网掩码地址
                    NSLog(@"netmask--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)]);
                    //--en0 端口地址
                    NSLog(@"interface--%@",[NSString stringWithUTF8String:temp_addr->ifa_name]);
                    
                }
            }
            
            temp_addr = temp_addr->ifa_next;
        }
    }
    
    // Free memory
    freeifaddrs(interfaces);
    
    in_addr_t i = inet_addr([address cStringUsingEncoding:NSUTF8StringEncoding]);
    in_addr_t* x = &i;
    
    unsigned char *s = getdefaultgateway(x);
    NSString *ip=[NSString stringWithFormat:@"%d.%d.%d.%d",s[0],s[1],s[2],s[3]];
    free(s);
    return ip;
}