获取本机IP地址

这里有两种方法：

//获取本机IP
- (NSString *)localIPAddress
{
    NSString *localIP = nil;
    struct ifaddrs *addrs;
    if (getifaddrs(&addrs)==0) {
        const struct ifaddrs *cursor = addrs;
        while (cursor != NULL) {
            if (cursor->ifa_addr->sa_family == AF_INET && (cursor->ifa_flags & IFF_LOOPBACK) == 0)
            {
                {
                    localIP = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)];
                    break;
                }
            }
            cursor = cursor->ifa_next;
        }
        freeifaddrs(addrs);
    }
    return localIP;
}

// 获取本机IP地址
- (NSString *)getIPAddress
{
    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) {
            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
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                }
            }
            
            temp_addr = temp_addr->ifa_next;
        }
    }
    
    // Free memory
    freeifaddrs(interfaces);
    
    return address;
}