获取iPhone上当前Wi-Fi接入点的IP地址？

Question

我正在尝试从我的iPhone连接到在我的计算机上运行在同一网络上的套接字服务器。如何获取运行套接字服务器的计算机的本地IP address？

Answer 1

#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <ifaddrs.h>

- (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;
}

Answer 2

您的服务器需要使用mDNS protocol广播自己。

然后在iPhone上，您只需使用gethostbyname即可获得IP address。您还有一个特定的API： DNS Service Discovery C Reference 。