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POObjC object changes to random objects: a memory issue
 

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  1. POObjC object changes to random objects: a memory issue
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    <p>long time listener, first time caller.</p> <p>I have a basic memory issue I don't understand, that I'm sure just about any one of you will see in a second. I'm playing around, trying to learn various ways of using UIWebViews, getting strings from URLs, and so on. Specifically, I'm trying to obtain one URL from another. In other words, I have uploaded an html page to the web, containing a URL. The address for that page is coded into the app, giving me a "hook" into the app - I can change the contents of that page and send the app a new URL any time I want. Make sense?</p> <p>So...retrieving the URL? No problem. Passing it into a string for later use - no problem. But when I set up a tap gesture recognizer, which should take that string, convert it back to an NSURL, and open it in Safari, I get a runtime crash. An NSLog call tells me that the string in question keeps being assigned to all sorts of random things.</p> <p>The relevant bits of my code follow. I'm sure some of you will tell me there are much better ways to do what I want - and that's certainly welcome. But I'd also really love to know what I'm doing wrong for this particular implementation, as I'm sure it's a basic misunderstanding that I'd like to correct.</p> <p>Thanks in advance. (And sorry about the formatting of the code block - haven't quite got the hang of posting on here!)</p> <pre><code> #import "Messing_With_Web_ViewsViewController.h" @implementation Messing_With_Web_ViewsViewController @synthesize tapView; NSString *finalURL; - (void)viewDidLoad { [super viewDidLoad]; NSString *firstString = @"http://www.my_web_address.html"; //Of course, I have the correct address here. NSURL *firstUrl = [NSURL URLWithString:firstString]; NSError * error; finalURL = [NSString stringWithContentsOfURL:firstUrl encoding:NSASCIIStringEncoding error:&amp;error]; if ( finalURL ) { NSLog(@"Text=%@", finalURL); //everything fine up to here; console prints the correct contents of "my web address" } else { NSLog(@"Error = %@", error); } //Taps UITapGestureRecognizer *tapRecognizer; tapRecognizer=[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(foundTap:)]; tapRecognizer.numberOfTapsRequired=1; tapRecognizer.numberOfTouchesRequired=1; [tapView addGestureRecognizer:tapRecognizer]; [tapRecognizer release]; } - (void)foundTap:(UITapGestureRecognizer *)recognizer { NSLog(@"Trying to load %@", finalURL); //at this point the app either crashes, or the console shows a random memory object [[UIApplication sharedApplication] openURL:[NSURL URLWithString: finalURL]]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; } - (void)viewDidUnload { } - (void)dealloc { [finalURL release]; [super dealloc]; } </code></pre> <p>@end</p>
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