Application crashing at Loading UIalertview indicator while loading data in iphone - iphone

Question

I am calling URL on my Search button event to load data. I have put the code for Loading indicator Alert view by taking NSThread. I am using 3.2 xcode with 4.3 iOS. Every thing run smooth but on search button it shows Loading indicator and then crashing and showing following in console
Program received signal: “EXC_BAD_ACCESS”.
warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.3.2 (8H7)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).
Code under the Search Button click event:
- (IBAction) searchButton {
if([addressField.text length]==0)
{
UIAlertView *myAlert = [[[UIAlertView alloc] initWithTitle:#"Alert" message:#"Please Tap on 'Show Me' & choose the 'Radius' first!!!" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil] autorelease];
[myAlert show];
}
else
{
[NSThread detachNewThreadSelector:#selector(updateFilterProgress) toTarget:self withObject:nil];
appDelegate = (MapTutorialAppDelegate *)[[UIApplication sharedApplication] delegate];
CLLocationCoordinate2D location;
float radius = [[arrayNo objectAtIndex:[pickerView selectedRowInComponent:0]] floatValue];
NSString *url = [NSString stringWithFormat:#"http://....url...../hespdirectory/phpsqlsearch_genxml.php?lat=%f&lng=%f&radius=%f",locationManager.location.coordinate.latitude,locationManager.location.coordinate.longitude,radius];
NSLog(#"%#", url);
NSURL *URL = [NSURL URLWithString:url];
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:URL];
//Initialize the delegate.
XMLParser *parser = [[XMLParser alloc] initXMLParser];
//Set delegate
[xmlParser setDelegate:parser];
//Start parsing the XML file.
BOOL success = [xmlParser parse];
if(success)
{
if([appDelegate.markers count] == 0){
UIAlertView *myAlert = [[[UIAlertView alloc] initWithTitle:#"Alert" message:#"No results fond!!!" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil] autorelease];
[myAlert show];
}
else
{
resultButton.userInteractionEnabled = YES;
for (int i = 0; i < [appDelegate.markers count]; i++)
{
marker *aMarker = [appDelegate.markers objectAtIndex:i];
location.latitude = [aMarker.lat floatValue];
location.longitude =[aMarker.lng floatValue];
AddressAnnotation *annob = [[AddressAnnotation alloc] initWithCoordinate:location];
annob.title = aMarker.name;
annob.subTitle = aMarker.address;
[mapView addAnnotation:annob];
[annob release];
CLLocationCoordinate2D ausLoc = {location.latitude,location.longitude}; //for zoom in the showroom results region
MKCoordinateSpan ausSpan = MKCoordinateSpanMake(0.108889, 0.169922);
MKCoordinateRegion ausRegion = MKCoordinateRegionMake(ausLoc, ausSpan);
NSLog(#"No Errors");
mapView.region = ausRegion;
}
}
}
else
NSLog(#"Error Error Error!!!");
[addressField resignFirstResponder];
}
}
And for NSThread to Show Loaading indicator while loading data at the back.
- (void) updateFilterProgress{
NSAutoreleasePool *pool = [NSAutoreleasePool new];
Reachability *r = [Reachability reachabilityWithHostName:#"www.google.com"];
NetworkStatus internetStatus = [r currentReachabilityStatus];
if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN))
{
UIAlertView *myAlert = [[[UIAlertView alloc] initWithTitle:#"No Internet Connection" message:#"This app require an internet connection via WiFi or cellular network to work." delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil] autorelease];
[myAlert show];
}
else{
UIAlertView *alertMe = [[[UIAlertView alloc] initWithTitle:#"Loading..." message:nil delegate:self cancelButtonTitle:nil otherButtonTitles: nil] autorelease];
[alertMe show];
UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
// Adjust the indicator so it is up a few pixels from the bottom of the alert
indicator.center = CGPointMake(alertMe.bounds.size.width / 2, alertMe.bounds.size.height - 50);
[indicator startAnimating];
[alertMe addSubview:indicator];
[indicator release];
[alertMe release];
for (int i = 200; i > [appDelegate.markers count]; i--)
{
marker *aMarker = [appDelegate.markers objectAtIndex:i];
[alertMe dismissWithClickedButtonIndex:0 animated:YES];
}
}
[pool release]; }
Is there anything remaining in my code. Pleas correct me....

Answer 1

The variable alertMe is autoreleased and therefore you can't just send a release message to it. Remove the line [alertMe release]; and it will run perfectly.

Answer 2

You are probably accessing a released object. To see which one it is, set NSZombiesEnabled - this will show you which already released object you try to access, and you should be able to identify your problem.
Please have a look here to see how to enable the zombies in XCode 4:
http://42games.net/quick-note-on-setting-nszombieenabled-environment-variable-in-xcode-4/