Transmitting a string via UDP using cocoaasyncsocket

I've been teaching myself Objective-C over the past few months; I'm building an iPhone app for my company. I started as (and still am) a complete novice, but until now I have had no problems easily finding answers to all my questions at various locations online.

For the final, and most important, piece of my app, I need to send a simple string to an address/port via UDP when a button is pressed. The string, address, and port are all variables pulled from an object passed to my view controller.

I have been digging around for two days looking at solutions and reading examples, but everything seriously reads like Greek to me. I'm not sure what major hunk of knowledge I seem to have missed out on, but I'm at a total loss. I learned about cocoaasyncsocket, and how "simple" it is, and it sounds perfect for what I need, but I just can't seem to wrap my mind around it. I'm really hoping someone here can help break it down for me into simple terms.

Here is a snipp开发者_如何学编程et of the code I've been trying, but with no luck. This code is from my viewController, with AsyncUdpSocket.h imported:

-(IBAction)udpButtonTwoPressed:(id)sender {
    NSData *myData;
    myData = [[NSData alloc] initWithData:([selectedObject
      valueForKey:@"udpCommandTwo"])];

    AsyncUdpSocket *mySocket;
    mySocket = [[AsyncUdpSocket alloc] initWithDelegate:self ];

    NSError *error = nil;
    if (!([mySocket connectToHost:([selectedObject
      valueForKey:@"serverIPAddress"]) onPort:([[selectedObject
      valueForKey:@"serverPort"] intValue]) error:&error])) {
        NSLog(@"Can't Connect Cause: %@", error);
        abort();
    }

    [mySocket close];

    [mySocket release];
    [myData release];
}

What am I doing wrong here?

There are two things that stand out from your example.

1. I don't see you writing anything to the socket. Have a look at writeData:withTimeout:tag.

2. CocoaAsyncSocket is asynchronous so in your example everything is going out of scope. If you are really wanted to write synchronously there is an example in the reference.

   NSString *customRunLoopMode = @"MySyncWrite";

   [asyncSocket addRunLoopMode:customRunLoopMode]; [asyncSocket writeData:didBackgroundData withTimeout:TIMEOUT_NONE tag:TAG_BG];

   syncWriteComplete = NO; BOOL runLoopReady = YES;

   while (runLoopReady && !syncWriteComplete) { runLoopReady = [[NSRunLoop currentRunLoop] runMode:customRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:1.0]]; }

   [asyncSocket removeRunLoopMode:customRunLoopMode];

HTH