StackOverflow2013

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copied!<p>I have used AsyncUdpSocket successfully to run SSDP Discovery and find controllers. Here are my code snippets:</p> <p>Initialize and setup the socket:</p> <pre><code>// AsyncUdpSocket *ssdpSock = [[AsyncUdpSocket alloc] initWithDelegate:self]; AsyncUdpSocket *ssdpSock = [[AsyncUdpSocket alloc] initIPv4]; [ssdpSock setDelegate:self]; </code></pre> <p>Note the first line commented out. I found on the <a href="http://groups.google.com/group/cocoaasyncsocket/msg/8b924d6d0ae4e4f3" rel="nofollow">AsyncUdpSocket forums</a> some issues with duplicates. I don't think I was facing them but I did it anyhow.</p> <p>I added error checking, and it was useful because during my debugging I wasn't closing sockets and I started getting socket setup failures:</p> <pre><code>NSError *socketError = nil; if (![ssdpSock bindToPort:1900 error:&socketError]) { NSLog(@"Failed binding socket: %@", [socketError localizedDescription]); return statusController; } if(![ssdpSock joinMulticastGroup:@"239.255.255.250" error:&socketError]){ NSLog(@"Failed joining multicast group: %@", [socketError localizedDescription]); return statusController; } if (![ssdpSock enableBroadcast:TRUE error:&socketError]){ NSLog(@"Failed enabling broadcast: %@", [socketError localizedDescription]); return statusController; } [ssdpSock sendData:[self.discoverControllerString dataUsingEncoding:NSUTF8StringEncoding] toHost:@"239.255.255.250" port:1900 withTimeout:2 tag:1]; </code></pre> <p>Notice the changes I have made to the time out. And then finally did the receive setup, and closed the socket. Note the socket close. Since I am in my own class when I am running this - the code above did not work for me.</p> <pre><code>[ssdpSock receiveWithTimeout: 2 tag:1]; [NSTimer scheduledTimerWithTimeInterval: 5 target: self selector:@selector(completeSearch:) userInfo: self repeats: NO]; [ssdpSock closeAfterSendingAndReceiving]; </code></pre> <p>The most important change probably was returning "NO" if I did not find my controller. The first receive was incidentally the discovery message itself coming back. And when I read through the AsyncUdpSocket.h file carefully - returning "NO" when it is not a packet you are looking for helped.</p> <p>Also note that I am using ARC in my code but I compiled the AsyncUdpSocket without ARC support.</p> <pre><code>-(void) completeSearch: (NSTimer *)t { NSLog(@"%s",__FUNCTION__); //[ssdpSock close]; //ssdpSock = nil; } - (BOOL)onUdpSocket:(AsyncUdpSocket *)sock didReceiveData:(NSData *)data withTag:(long)tag fromHost:(NSString *)host port:(UInt16)port { NSLog(@"%s %ld %@ %d",__FUNCTION__,tag,host,port); NSString *aStr = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]; NSLog(@"%@",aStr); NSString *compareString = [aStr stringByPaddingToLength:[self.responseString length] withString:@"." startingAtIndex:0]; //NSLog(@"%@", compareString); //NSLog(@"%@", self.responseString); if ([compareString isEqualToString:self.responseString]) { NSLog(@"String Compare, Controller Found!"); [self.controllerList addObject:aStr]; //NSData *controllerIP = [aStr dataUsingEncoding:NSUTF8StringEncoding]; [[NSNotificationCenter defaultCenter] postNotificationName:@"DiscoveredController" object:nil]; return YES; } return NO; } </code></pre>

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