Question

请原谅我的iPhone / Objective-C新手状态！

我发现我的HTTP服务器使用NSNetServiceBrowser，但现在我只想找到服务的IP地址和端口。

我的委托方法中有以下内容：

NSNetService* server = [serverBrowser.servers objectAtIndex:0];

NSString            *name = nil;
NSData              *address = nil;
struct sockaddr_in  *socketAddress = nil;
NSString            *ipString = nil;
int                 port;
uint                 i;
for (i = 0; i < [[server addresses] count]; i++)
{
    name = [server name];
    address = [[server addresses] objectAtIndex:i];
    socketAddress = (struct sockaddr_in *)
    [address bytes];
    ipString = [NSString stringWithFormat: @"%s",
                inet_ntoa (socketAddress->sin_addr)];
    port = socketAddress->sin_port;
    NSLog(@"Server found is %s %d",ipString,port);
}

但是永远不会输入for循环，即使调用了委托。有任何想法吗？谢谢！

Answer 1

我意识到这是一个老线程，但我也遇到了这个问题。上面的代码存在一些问题：

这不是IPv6精明。在一个最小，它应该检测和如果剩下的话，丢弃IPv6地址您的应用只能处理v4 地址，但理想情况下你应该准备通过这两个地址上游家庭。
端口分配将为英特尔生成错误的值处理器。您需要使用htons 解决这个问题。
正如安德鲁上面提到的那样迭代应该使用增强 for loop。
（编辑：已添加此内容）正如另一个相关主题所述，不鼓励使用inet_ntoa以支持inet_ntop。

将所有这些放在一起，你得到：

char addressBuffer[INET6_ADDRSTRLEN];

for (NSData *data in self.addresses)
{
    memset(addressBuffer, 0, INET6_ADDRSTRLEN);

    typedef union {
        struct sockaddr sa;
        struct sockaddr_in ipv4;
        struct sockaddr_in6 ipv6;
    } ip_socket_address;

    ip_socket_address *socketAddress = (ip_socket_address *)[data bytes];

    if (socketAddress && (socketAddress->sa.sa_family == AF_INET || socketAddress->sa.sa_family == AF_INET6))
    {
        const char *addressStr = inet_ntop(
                socketAddress->sa.sa_family,
                (socketAddress->sa.sa_family == AF_INET ? (void *)&(socketAddress->ipv4.sin_addr) : (void *)&(socketAddress->ipv6.sin6_addr)),
                addressBuffer,
                sizeof(addressBuffer));

        int port = ntohs(socketAddress->sa.sa_family == AF_INET ? socketAddress->ipv4.sin_port : socketAddress->ipv6.sin6_port);

        if (addressStr && port)
        {
            NSLog(@"Found service at %s:%d", addressStr, port);
        }
    }
}

Answer 2

您在回调中返回的NSNetService尚未准备好使用。您必须调用以下方法来获取它的地址：

- (void)resolveWithTimeout:(NSTimeInterval)timeout;

实现NSNetService委托方法以找出它何时解析：

- (void)netServiceDidResolveAddress:(NSNetService *)sender;

此时，服务中至少应有一个地址。

另外，请仔细阅读文档和头文件！这个问题有一些复杂性，我已经掩饰了。

Answer 3

重新分类接受的答案：

NSNetService + Util.h

#import <Foundation/Foundation.h>

@interface NSNetService (Util)

- (NSArray*) addressesAndPorts;

@end


@interface AddressAndPort : NSObject 

@property (nonatomic, assign) int port;
@property (nonatomic, strong)  NSString *address;

@end

NSNetService + Util.m

#import "NSNetService+Util.h"
#include <arpa/inet.h>

@implementation NSNetService (Util)

- (NSArray*) addressesAndPorts {

    // this came from http://stackoverflow.com/a/4976808/8047
    NSMutableArray *retVal = [NSMutableArray array];
    char addressBuffer[INET6_ADDRSTRLEN];

    for (NSData *data in self.addresses)
    {
        memset(addressBuffer, 0, INET6_ADDRSTRLEN);

        typedef union {
            struct sockaddr sa;
            struct sockaddr_in ipv4;
            struct sockaddr_in6 ipv6;
        } ip_socket_address;

        ip_socket_address *socketAddress = (ip_socket_address *)[data bytes];

        if (socketAddress && (socketAddress->sa.sa_family == AF_INET || socketAddress->sa.sa_family == AF_INET6))
        {
            const char *addressStr = inet_ntop(
                                               socketAddress->sa.sa_family,
                                               (socketAddress->sa.sa_family == AF_INET ? (void *)&(socketAddress->ipv4.sin_addr) : (void *)&(socketAddress->ipv6.sin6_addr)),
                                               addressBuffer,
                                               sizeof(addressBuffer));

            int port = ntohs(socketAddress->sa.sa_family == AF_INET ? socketAddress->ipv4.sin_port : socketAddress->ipv6.sin6_port);

            if (addressStr && port)
            {
                AddressAndPort *aAndP = [[AddressAndPort alloc] init];
                aAndP.address = [NSString stringWithCString:addressStr encoding:kCFStringEncodingUTF8];
                aAndP.port = port;
                [retVal addObject:aAndP];
            }
        }
    }
    return retVal;

}


@end


@implementation AddressAndPort
@end

[是的，我不用担心会创建很多NSObject个实例......]

iPhone：Bonjour NSNetService IP地址和端口

3 个答案:

NSNetService + Util.h

NSNetService + Util.m