The following code should add different objects to an NSMutableArray however it adds the same object each time:-
for(int i =0; i < [results count];i++)
{
Reservation *r = [[Reservation alloc] init];
NSDictionary *dict = [results objectAtIndex: i];
r.resId = [dict objectForKey:#"reservationrequest_id"];
r.driver = [dict objectForKey:#"driver_name"];
r.vehicle = [dict objectForKey:#"billing_registration"];
r.startDate = [dict objectForKey:#"hire_from_date"];
r.endDate = [dict objectForKey:#"hire_to_date"];
r.status = [dict objectForKey:#"status_type"];
[self.bookingsObjectArray addObject:r];
[r release];
r = nil;
}
I have exactly the same code that works fine in another part of my app it just uses a Groups class instead of Reservation.
When debugging the code I found that when it does [r release]; 'r' is greyed out but still keeps the same pointer. When it goes back to Reservation *r = [[Reservation alloc] init];
'r' has the same pointer as last time.
Any ideas what might be causing the problem? Thanks in advance.
Chris
I'm having issues with a singleton I've created. It contains two NSMutableDictionary's, which are read and used in three views (and some modal views) throughout the app.
I've added an MKMapView t plot some of the venues inside the dictionaries on a map. When I use the exact same method/function used in every other view to access the data, I receive an EXC_BAD_ACCESS error pertaining to a deallocated dictionary. This comes from NSZombieEnabled:
CFDictionary retain: message sent to deallocated instance
In a dsym'ed trace, it is the replacement of one dictionary with another that is causing grief. The code I'm using to call the function comes from a MKAnnotationView click:
UIControl *tempButton = sender;
NSString *selectedEventsString = [self.eventsArray objectAtIndex:tempButton.tag];
NSLog(#"eventString: %#", selectedEventsString);
[[EventsManager eventsManager] changeSelectedEventsDictionaryTo:selectedEventsString];
[tempButton release];
[selectedEventsString release];
"selectedEventsString" is coming out to a perfectly corresponding event.
The corresponding code in EventsManager:
-(void)changeSelectedEventsDictionaryTo:(NSString *)eventName {
NSLog(#"singleton: %#", eventName);
self.eventString = eventName;
self.selectedEventsDictionary = [self.eventsDictionary objectForKey:eventName];
}
Both selectedEventsDictionary and eventsDictionary are set as #property (nonatomic, retain) in the .H file, and this is the init function:
+ (EventsManager*)eventsManager {
if (eventsManager == nil) {
eventsManager = [[super allocWithZone:NULL] init];
eventsManager.eventsDictionary = [[NSMutableDictionary alloc] init];
eventsManager.selectedEventsDictionary = [[NSMutableDictionary alloc] init];
eventsManager.eventString = [[NSString alloc] init];
eventsManager.mode = [[NSString alloc] init];
}
return eventsManager;
}
This is an example of code used in other views that works fine:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSUInteger row = [indexPath row];
NSString *eventString = [self.eventsArray objectAtIndex:row];
[[EventsManager eventsManager] changeSelectedEventsDictionaryTo:eventString];
//Modal display code here
}
Any help would be greatly appreciated! I think I've provided all relevant code but let me know if more is needed.
Cheers!
Where to start! I will point out some things that I do see wrong.
First Example. Do not release tempButton and selectedEventString as you never explicitly called retain/copy or alloc and init on them.
UIControl *tempButton = sender;
NSString *selectedEventsString = [self.eventsArray objectAtIndex:tempButton.tag];
NSLog(#"eventString: %#", selectedEventsString);
[[EventsManager eventsManager] changeSelectedEventsDictionaryTo:selectedEventsString];
//DO NOT RELEASE THESE YOU NEVER RETAINED THEM!
[tempButton release];
[selectedEventsString release];
Your static eventsManager is not thread safe which may not be a issue for you but should definitely be looked into.
Read the comments for the following code example
+ (EventsManager*)eventsManager {
if (eventsManager == nil) { //<-- Not thread safe
//DO NOT CALL SUPER USE self
//eventsManager = [[self alloc] init];
eventsManager = [[super allocWithZone:NULL] init];
//You need to autorelease these values or use an autoreleased static method
//eventsManager.eventsDictionary = [NSMutableDictionary dictionary];
//eventsManager.selectedEventsDictionary = [NSMutableDictionary dictionary];
eventsManager.eventsDictionary = [[NSMutableDictionary alloc] init];
eventsManager.selectedEventsDictionary = [[NSMutableDictionary alloc] init];
//Do not bother setting these at all or just set them to nil
eventsManager.eventString = [[NSString alloc] init];
eventsManager.mode = [[NSString alloc] init];
}
return eventsManager;
}
Make sure all of those properties are set to retain or copy and that may fix your problem. If you still have an issue after these fixes you can update your question and I will update my answer.
I have got I have got two methods both in different classes. One is class method and other is instance method. i am calling class method from instance method. When instance method finishes it gives runtime error "EXC_BAD_ACCESS".
#import "xmlObject.h"
#import "textmeAppDelegate.h"
#implementation Class1
- (void)method1 {
textmeAppDelegate *del = (textmeAppDelegate *)[[UIApplication sharedApplication] delegate];
NSArray *bgColor = [[NSArray alloc] initWithArray:[xmlObject fetchImmediateChildrenValues:[del.navigationbarStyle objectForKey:#"backgroundcolor"]]];
UIColor *color = [UIColor colorWithRed:[[bgColor objectAtIndex:3] floatValue] green:[[bgColor objectAtIndex:2] floatValue] blue:[[bgColor objectAtIndex:1] floatValue] alpha:[[bgColor objectAtIndex:0] floatValue]];
CGContextSetFillColor(context, CGColorGetComponents([color CGColor]));
CGContextFillRect(context, rect);
[bgColor release];
}
#end
#implementation xmlObject
+ (NSArray *) fetchImmediateChildrenValues:(NSMutableDictionary *) node {
NSMutableDictionary *tmp = [[node objectForKey:#"children"] retain];
NSArray *keys = [[NSArray alloc] initWithArray:[tmp allKeys]];
keys = [keys sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
NSMutableArray *pushArr = [[[NSMutableArray alloc] init] autorelease];
NSString *val = [[NSString alloc] init];
for(NSString *str in keys) {
val = (NSString *)[[tmp objectForKey:str] objectForKey:#"innertext"];
[pushArr addObject:val];
}
[val release];
[keys release];
return [NSArray arrayWithArray:pushArr];
}
#end
What is wrong with the code? Also app is crashing for this line of code
application is crashing if i include this line
NSArray *bgColor = [[NSArray alloc] initWithArray:[xmlObject fetchImmediateChildrenValues:[del.navigationbarStyle objectForKey:#"backgroundcolor"]]];
If I remove it application runs smoothly.
I have several comments on your code. One of them is the immediate cause of your crash, but you need to fix at least one other issue too. The short answer is that you over release val and keys.
NSArray *bgColor = [[NSArray alloc] initWithArray:[xmlObject fetchImmediateChildrenValues:[del.navigationbarStyle objectForKey:#"backgroundcolor"]]];
You don't need to create a new array here, you can simply write the following:
NSArray *bgColor = [xmlObject fetchImmediateChildrenValues:[del.navigationbarStyle objectForKey:#"backgroundcolor"]];
if you do, you don't need the [bgColor release] further down.
NSArray *keys = [[NSArray alloc] initWithArray:[tmp allKeys]];
keys = [keys sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
These two lines leak the first NSArray, you alloc it but you overwrite it straight away with the sorted version. In fact, you can simply write:
keys = [[tmp allKeys] sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
Note that you do not own keys so you can get rid of the [keys release] line further down.
NSString *val = [[NSString alloc] init];
for(NSString *str in keys) {
val = (NSString *)[[tmp objectForKey:str] objectForKey:#"innertext"];
[pushArr addObject:val];
}
[val release];
This is the source of your immediate problem. You first alloc a new string. Then you immediately overwrite it on each iteration of your loop. So the allocated NSString leaks. You do not own the val returned by [[tmp objectForKey:str] objectForKey:#"innertext"]; on each iteration, so the release ov val after the loop should not be there.
On a side note, objectForKey: returns an id - the cast to NSString* is redundant. Most people leave it out.
[keys release];
Going back to the bit above where I told you that you were leaking your alloc'd keys? Well the new version of keys you overwrote it with you don't own. Therefore you must not release keys here.
return [NSArray arrayWithArray:pushArr];
This is fine. My preference would be for:
return [[pushArray copy] autorelease];
but it is just a matter of style. You could also just return pushArray, but pushArray is mutable and the caller may rely on the return value being immutable.
Test your code with NSZombieEnabled set... It should give you enough informations to fix your problem.
I have a tableview with a navigationBar with a segmentedControl on the top of the view. I have set up the segmentedControl with buttons that sort the table by either "FirstName" or "LastName". It works perfectly the first 2-4 of times you press the sorting buttons, but then the app crashes.
The debugger and console seem to be of no help finding the source of the bug. Does anyone see any glaring mistakes in my code?
Here is my code below, let me know if you have any questions. Thanks!
- (IBAction)sortingSegmentAction:(id)sender{
NSString *keyToSortBy = [NSString alloc];
if([sender selectedSegmentIndex] == 0)
{
self.sortingSegmentActionPressed = 0;
keyToSortBy = #"FirstName";
}
else if([sender selectedSegmentIndex] == 1)
{
self.sortingSegmentActionPressed = 1;
keyToSortBy = #"LastName";
}
//Create the sort descriptors
NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:keyToSortBy ascending:YES] autorelease];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
//Sort allSubItams by the values set in the sort descriptors
NSArray *sortedArray;
self.sortedArray = [allSubItems sortedArrayUsingDescriptors:sortDescriptors];
//Recreate the data structure by putting the newly sorted items into a dictionary sorted by inital letters.
NSDictionary *eachItemList; //A DICTIONARY FOR PUTTING ALL THE DATA FOR EACH ITEM IN IT'S OWN SECTION
NSMutableDictionary *tempSectionedDictionaryByFirstLetter = [[NSMutableDictionary alloc] init];
for (eachItemList in sortedArray) //eachElementList is a dictionary with a section for each item
{
NSDictionary *aDictionary = [[NSDictionary alloc] initWithDictionary:eachItemList];
NSString *firstLetterString;
firstLetterString = [[aDictionary valueForKey:keyToSortBy]substringToIndex:1];
NSMutableArray *existingArray;
if (existingArray = [tempSectionedDictionaryByFirstLetter valueForKey:firstLetterString])
{
[existingArray addObject:eachItemList];
} else {
NSMutableArray *tempArray = [NSMutableArray array];
[tempSectionedDictionaryByFirstLetter setObject:tempArray forKey:firstLetterString];
[tempArray addObject:eachItemList];
}
[aDictionary release];
[eachItemList release];
}
//Set the data source for the table (sectionedDictionaryByFirstLetter) to tempSectionedDictionaryByFirstLetter.
self.sectionedDictionaryByFirstLetter = tempSectionedDictionaryByFirstLetter;
NSMutableArray *keyArray = [[NSMutableArray alloc] init];
[keyArray addObjectsFromArray:[[self.sectionedDictionaryByFirstLetter allKeys] sortedArrayUsingSelector:#selector(compare:)]];
self.keys = keyArray;
[self.tableView reloadData];
[keyArray release];
[tempSectionedDictionaryByFirstLetter release];
}
Don't release eachItemList at the end of your loop. You did not explicitly allocate it in this context so you shouldn't release it.
The for (object in array) loop gives you a reference to the object in the array, not a copy. By sending a release message to this reference, you are decrementing the retain count of this object while it is still in the array. After a few times (depending on how many times the object has been retained, NSArray for example retains objects when they are added to the array) it's retain count will reach 0, and it will then become deallocated and you'll get crashes regarding unrecognised selectors or EXC_BAD_ACCESS and possibly other kinds of errors.
I'm a beginner at C, Obj-C and the iPhone, and I'm trying getting to grips with a lot of terminology used. I hope one of ye can help with a problem I have been struggling with for a few days now.
My code below is a method which call up a nib containing a search field and a table. The table is populated from a search of the array created for 'theList' below. Using 'Instruments', I am getting a Leak at the line:
NSDictionary *theItem = [NSDictionary dictionaryWithObjectsAndKeys:clientName,#"Name",clientId,#"Id",nil]; , but I can't figure out why :(
I know it's probably a difficult question to answer, but if any one can be of any help!
- (void)editClient:(id)sender {
if (pickList == nil) {
pickList = [[PickFromListViewController alloc] initWithNibName:#"PickList" bundle:nil];
}
TimeLogAppDelegate *appDelegate = (TimeLogAppDelegate *)[[UIApplication sharedApplication] delegate];
NSMutableArray *theList = [[NSMutableArray alloc] init];
int i;
for (i=0;i < [appDelegate.clients count];i++) {
Client *thisClient = [appDelegate.clients objectAtIndex:i];
NSString *clientName = [[NSString alloc] initWithString: thisClient.clientsName];
NSNumber *clientId = [[NSNumber alloc] init];
clientId = [NSNumber numberWithInt:thisClient.clientsId];
NSDictionary *theItem = [NSDictionary dictionaryWithObjectsAndKeys:clientName,#"Name",clientId,#"Id",nil];
[theList addObject:theItem];
theItem = nil;
[clientName release];
[clientId release];
}
[pickList createSearchItems:theList :NSLocalizedString(#"Client",nil)];
[theList release];
appDelegate.returningID = [NSNumber numberWithInt: projectsClientsId];
[self.navigationController pushViewController:pickList animated:YES];
}
Thanks in advance!
This returns allocated NSNumber instance.
NSNumber *clientId = [[NSNumber alloc] init];
This line overwrites the above clientId with another instance of NSNumber, numberWithInt returns autoreleased object, since you haven't allocated memory for it you should not call release, it will be released automatically.
clientId = [NSNumber numberWithInt:thisClient.clientsId];
You are calling release on clientId so you get memory problem.
To fix it remove the first line above which is useless in this case and update the second one to:
NSNumber * clientId = [NSNumber numberWithInt:thisClient.clientsId];
Then remove the:
[clientId release]
Because the clientId will be released automatically.
EDIT: Re still have problems ...
I'm not sure how to you manipulate the clients in app delegate, otherwise the code should work ok, I created small example, omitting the parts that I can't see (app delegate and clients):
// command line utility - foundation tool project:
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSMutableArray * theList = [[NSMutableArray alloc] init];
int i = 0;
for (i = 0; i < 10; ++i)
{
NSString * clientName = [NSString stringWithString:#"client"]; //no need to release
NSNumber * clientId = [NSNumber numberWithInt:i];
NSDictionary * theItem = [NSDictionary dictionaryWithObjectsAndKeys:
clientName, #"name",
clientId, #"id",
nil];
[theList addObject:theItem];
}
for (id item in theList) for (id key in item) NSLog(#"%# - %#", key, [item objectForKey:key]);
[theList release];
[pool drain];
return 0;
}
You are creating clientID with [[NSNumber alloc] init], and then immediately overwriting it with an autoreleased NSNumber instance [NSNumber numberWithInt], and then you are releasing it later in your code, which you shouldn't do. Get rid of the [[NSNumber alloc] init] line and the [clientId release] line and that should fix it up a little.
Aside from the obvious leak of the NSNumber, there are a few other things I'd fix that may help. Most are fairly minor, but in my experience with Objective-C, less code == clearer code, something that is not equally true for languages like Bash or Perl. ;-)
- (void) editClient:(id)sender {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
if (pickList == nil) {
pickList = [[PickFromListViewController alloc] initWithNibName:#"PickList" bundle:nil];
}
TimeLogAppDelegate *appDelegate = (TimeLogAppDelegate*)[[UIApplication sharedApplication] delegate];
NSMutableArray *searchItems = [NSMutableArray array];
NSMutableDictionary *itemDict = [NSMutableDictionary dictionary];
for (Client *client in appDelegate.clients) {
[itemDict setObject:[client.clientsName copy] forKey:#"Name"];
[itemDict setObject:[NSNumber numberWithInt:client.clientsId] forKey:#"Id"];
[searchItems addObject:[[itemDict copy] autorelease]];
}
[pickList createSearchItems:searchItems :NSLocalizedString(#"Client",nil)];
[self.navigationController pushViewController:pickList animated:YES];
appDelegate.returningID = [NSNumber numberWithInt: projectsClientsId];
[pool drain];
}
There are a few mysterious points that make me suspicious:
The line just after the for loop tells pickList to do something with the NSMutableArray. That method should retain the new array, as well as release the old array if one exists. If you just overwrite the pointer, the old array will be leaked. (Also, this method is poorly named. Anonymous arguments (a colon with no preceding text) are legal in Objective-C, but considered extremely bad practice. Consider renaming the method to better express what it does.)
The next line seems to associate the pick list with a navigation controller. If it is custom code, make sure the -pushViewController:animated: method properly releases an existing pick list when a new one is specified.
Assigning to appDelegate.returningID is assumed to call the setter for a returningID property. Be sure that property retains or copies the NSNumber as necessary.
Memory leaks can be tricky to track down, even in Instruments, and you'll often find that it looks like Foundation classes (such as NSDictionary) are leaking like a sieve, but I have always been able to trace it back to an abnormality in my code. :-)