NSNetService works fine, but can't get hostName, resolve causes error

问题

I'm using Bonjour with an NSNetService to publish a server from my iPhone. It all works as expected, I can browse the pages I'm serving etc. However, on the iPhone I want to display the host name (i.e. the URL, like "myDevice.local."), so that one can also enter the address manually in a browser (useful for clients missing a bonjour discovery service). My understanding is that calling the method [myNetService hostName] should give me that address. However, this call always returns nil. I read on some forum that I first should resolve the service, however both [myNetService resolve] and [myNetService resolveWithTimeout:10] call the delegate method

- (void)netService:(NSNetService *)sender didNotResolve:(NSDictionary *)errorDict;

with the error

{
    NSNetServicesErrorCode = -72003;
    NSNetServicesErrorDomain = 10;
}

which apparently means that it is already resolved. Again, all this is happening while i can use the service. Also I can get the port, the domain, and the type of the service. The only other strange thing is that the call [myNetService addresses] returns an empty array.

I'm using SDK 3.1.3. Does anybody have an idea what I could be doing wrong?

回答1:

You can get the hostname via [[NSProcessInfo processInfo] hostName] without resolving the netservice you just published.

回答2:

The [[NSProcessInfo processInfo] hostName] method was not useful for me for two reasons:

If celular data is active, it returns some weird hostname at my provider's domain
If there's only WiFi, the host name is ok, but all lower case

The following code from http://iphoneappcode.blogspot.com/2012/05/how-to-get-device-ipaddess-in-iphone.html worked best for me, always returning the local host name with sensitive case:

+ (NSString *) hostname
{
    char baseHostName[256]; 
    int success = gethostname(baseHostName, 255);
    if (success != 0) return nil;
    baseHostName[255] = '\0';

#if !TARGET_IPHONE_SIMULATOR
    return [NSString stringWithFormat:@"%s.local", baseHostName];
#else
     return [NSString stringWithFormat:@"%s", baseHostName];
#endif
}

回答3:

Check this link out:

This says your error it was still trying to resolve the service:

https://developer.apple.com/library/IOs/documentation/Cocoa/Reference/Foundation/Classes/NSNetService_Class/index.html#//apple_ref/c/tdef/NSNetServicesError

来源：https://stackoverflow.com/questions/6496129/nsnetservice-works-fine-but-cant-get-hostname-resolve-causes-error

标签

objective-c

ios

bonjour

hostname

nsnetservice