I have an array for IBOutlet collection
.h
#interface UpisiRezultat : UIViewController {
NSArray *buttons;
}
#property (nonatomic, retain) IBOutletCollection(UIButton) NSArray *buttons;
.m
#synthesize buttons;
- (void)viewDidLoad
{
[self setValue:[UIFont fontWithName:#"NeverSayNever" size:22] forKeyPath:#"buttons.font"];
[super viewDidLoad];
}
- (void)viewDidUnload
{
buttons = nil;
}
- (void)dealloc
{
[buttons release]; --> Error
[super dealloc];
}
Why does my program crash when I have [buttons release]; in dealloc?
Without it, it doesn't crash...
updated(Dec1) code and Tested.
- (void)dealloc {
self.buttons = nil;
[super dealloc];
}
you should not release them.
http://www.bobmccune.com/2011/01/31/using-ios-4s-iboutletcollection/
If you have made a connection to your buttons with Interface Builder, it's your view that owns it and will release it.
Since buttons is an NSArray and it is explicitly retained, then it must be released and then set to nil in -dealloc.
See Darren's answer at: Settings IBOutlets to nil in dealloc
See an IBOutletCollection example at: http://www.bobmccune.com/2011/01/31/using-ios-4s-iboutletcollection/.
Related
I am using following code to create NSMutableArray. When I run the same in “Profile” mode, it is showing a memory leakage.
SampleArray.h
#interface SampleArray: NSObject {
}
#property (assign, retain) NSMutableArray *array;
#end
SampleArray.m
#import "SampleArray.h"
#implementation SampleArray
#synthesize array;
-(void) viewDidLoad {
self.array =[ [NSMutableArray alloc] init];
}
-(void) viewWillDisappear:(BOOL)animated {
[self.array release];
}
#end
When I am using autorelease, then I can’t able to access the same in other function or method and return null value. Please help me to find the issue.
releasing this array in viewWilLDisappear is not a good idea, you should release in the dealloc function. You should worry about over-releasing this item and causing a program crash since viewWilLDisappear may get called multiple times during the lifetime of this ViewController.
Anyhow, you are double retaining the item beacuse your property has a retain on it (and make it nonatomic, not assign), add an autorelease to your alloc/init:
self.array =[[[NSMutableArray alloc] init] autorelease];
and move
[array release];
to your dealloc function. Or convert to ARC and don't worry any longer...
Try setting it to (nonatomic, retain), then autoreleasing.
It is better to handle memory de-allocation in your -dealloc() and set your array to nil to be more secure in your -viewDidUnload()
so it will be:
-(void) viewDidUnload
{
self.array = nil;
}
-(void) dealloc
{
[array release];
[super dealloc];
}
and like other people said, declare your property as (nonatomic, retain) instead of (assign, retain)
First of all I'm assuming that you are using
#property (nonatomic, retain) NSMutableArray *array;
use this
-(void) viewDidLoad {
array =[[NSMutableArray alloc] init];
}
-(void) viewWillDisappear:(BOOL)animated {
[array release];
}
I will recommend you to use dealloc instead of viewWillDisappear
-(void) dealloc {
[array release];
[super dealloc];
}
Explanation of your code
-(void) viewDidLoad {
// here you are allocating a mutable array thus retain count becomes one
// then you are assigning it to the property which is retain and thus retains it
// making the retain count 2
self.array =[ [NSMutableArray alloc] init];
}
-(void) viewWillDisappear:(BOOL)animated {
// here you are releasing it so its retain count becomes 1 from 2
// thus shows memory leak
[self.array release];
}
I try to save numbers from a textfield on one viewController in a NSMutableArray when I press a button on this viewContoller. (this is working now)
Then i want the numbers give out on a textview which is on a secondViewController but this dont work. When i want to give out the array on the first Viewcontroller it work fine.
Also i cant erase the NSMutableArray with a button on the SecondviewController.
The SecondviewController have the same class like the viewController.
Can someone show me how i can give out an array on a seconviewcontroller?
Hallo,
at the moment i have this:
//ViewController.h:
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController {
NSMutableArray *textViewArray;
}
#property (strong, nonatomic) IBOutlet UITextField *textLable2;
#property (strong, nonatomic) IBOutlet UITextField *textLable1;
- (IBAction)setArrayWithCurrentNumber:(id)sender;
- (IBAction)returnToTextfield:(id)sender;
#end
//this the .m file:
#import "ViewController.h"
#implementation ViewController
#synthesize textLable2;
#synthesize textLable1;
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
textViewArray = [[NSMutableArray alloc]init];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[self setTextLable2:nil];
[self setTextLable1:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
- (IBAction)setArrayWithCurrentNumber:(id)sender
{
NSString *string1 = self.textLable1.text;
[textViewArray addObject:string1];
NSMutableArray *array = [NSMutableArray arrayWithArray:textViewArray];
NSString *string2 = [array componentsJoinedByString:#" "];
self.textLable2.text = [NSString stringWithString:string2];
NSLog(#"%#",textViewArray);
}
- (IBAction)returnToTextfield:(id)sender
{
[textLable1 resignFirstResponder];
[textLable2 resignFirstResponder];
}
#end
If you're calling the second view controller from the first one you could set a property on the second one to hold the NSMutableArray or just send it on the initializer.
something like:
- (id)initWithArray:(NSMutableArray *)array {
if (self = [super init]) {
myArray = [array copy];
}
return self;
}
assuming your second view controller has declared NSMutableArray * myArray;
Edit: Adding some more code in here...
// I'll assume you use some kind of UINavigationController to show your content
- (void)showSecondViewController {
SecondViewController * vc = [[[SecondViewController alloc] initWithArray:yourMutableArray] autorelease];
[self.navigationController pushViewController:vc];
}
I'm doing a simple change password through a web service project, using sudzc to generate the SOAP requests.
When I run the project, I just keep receiving nothing in the simulator.
Here's my code:
.h
#import <UIKit/UIKit.h>
#interface ChangePasswordViewController : UIViewController {
NSString *CPstr1;
NSString *CPstr2;
NSString *CPstr3;
IBOutlet UITextField *CPText1;
IBOutlet UITextField *CPText2;
IBOutlet UITextField *CPText3;
}
#property (nonatomic,retain) IBOutlet UITextField *CPText1;
#property (nonatomic,retain) IBOutlet UITextField *CPText2;
#property (nonatomic,retain) IBOutlet UITextField *CPText3;
#property (nonatomic,retain) IBOutlet UITextView *CPResult;
-(IBAction) CPSendString;
#end
viewcontroller.m
#import "ChangePasswordViewController.h"
#import "MINEHBJTService.h"
#implementation ChangePasswordViewController
#synthesize CPText1,CPText2,CPText3;
#synthesize CPResult;
//to send the user's old and new password to CPstr
-(IBAction) CPSendString{
CPstr1 = [[NSMutableString alloc] initWithString:CPText1.text];
CPstr2 = [[NSMutableString alloc] initWithString:CPText2.text];
CPstr3 = [[NSMutableString alloc] initWithString:CPText3.text];
MINEHBJTService *service = [[MINEHBJTService alloc] init];
[service ChangePassword: self action: #selector(handleChangePassword:)
sUserID:CPstr1 sPassWord:CPstr2 sNewPassword:CPstr3];
return;
}
-(void) hadleChanePassword:(int)value{
int result = value;
if(result==1){
CPResult.text = #"Change password sucessed";
}
else {
CPResult.text = #"Change password failed";
}
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[CPstr1 release];
[CPstr2 release];
[CPstr3 release];
CPResult.text = #"";
[ MINEHBJTService release];
[super dealloc];
}
#end
In the service call you define the callback method as handleChangePassword. However, the actual implementation of this method is mispelled as hadleChanePassword.
Fix the naming and you should start seeing something in the output field in the simulator.
So, I'm loading by XIB file and it contains a set of UIBarButtonItems. Some of the items are used when the viewDidLoad: is called.
#interface MyViewController : UIViewController {
IBOutlet UIBarButtonItem *addButton;
IBOutlet UIBarButtonItem *editButton;
IBOutlet UIBarButtonItem *doneButton;
}
// NB: There are no properties retaining anything.
#end
#implementation MyViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *initialToolbarItems =
[[NSArray alloc] initWithObjects: addButton, editButton, nil];
self.toolbarItems = initialToolbarItems;
[initialToolbarItems release];
}
- (void)dealloc {
[super dealloc];
// Nothing else to do here since we are not retaining anything.
// … or are we? <insert dramatic music here>
}
#end
If I push the above the above ViewController onto a UINavigationController everything seems fine, all the IBOutlets are assigned and behave like expected.
The instant i pop the ViewController from the navigation stack Instruments' Leaks tells me that I am leaking a UIBarButtonItem. Woe is me!
If I change dealloc: to
- (void)dealloc {
[doneButton release];
[super dealloc];
}
no leaks occur. The same goes if I use doneButton in viewDidLoad:
NSArray *initialToolbarItems =
[[NSArray alloc] initWithObjects: addButton, editButton, doneButton, nil];
My question: Why is my IBOutlet leaking when I don't use it. I don't retain it at any point. The the NIB loader should own the object, right?
Only thing I can think of:
The nib loader treats IBOutlets as strong references. All outlets are retained by default unless you specifically indicate assign. So you still need to release them in dealloc and viewDidUnload.
You can also use a assigned property to make it a weak reference:
#property (nonatomic, assign) IBOutlet UIBarButtonItem *doneButton;
Some reading: http://weblog.bignerdranch.com/?p=95
If you have #property with (retain) declared for the your IBOOutlets they will be retained and must be released
The array retains them
I have an iPhone application that loads succesive views in a framework based on the one explained in this link (basically a main ViewController that loads/removes additional views with a displayView method). In my application I am using NIBs (the example link uses coded views) though so each of my ViewControllers has its accompanying nib.
Debugging in Instruments shows no leaks but if I enter/leave a section (ViewController with its View.xib), the nib remains in memory so after a few in/outs memory starts to accumulate.
I know the nib is not being unloaded because one is almost programmatically created (no stuff in IB) while another does have images and buttons created in IB. The large one is loaded first and the small one loads next. You would expect a reduction in allocation in Instruments.
How can I prevent this?
My structure is as follows, with a few comments below:
`MyAppDelegate.h`
#import <UIKit/UIKit.h>
#class RootViewController;
#interface MyAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
RootViewController *viewController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet RootViewController *viewController;
-(void) displayView:(int)intNewView;
#end
`MyAppDelegate.m`
#import "MyAppDelegate.h"
#import "RootViewController.h"
#implementation MyAppDelegate
#synthesize window;
#synthesize viewController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[window addSubview:viewController.view];
[window makeKeyAndVisible];
return YES;
}
- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application {
}
-(void) displayView:(int)intNewView {
[viewController displayView:intNewView];
}
- (void)dealloc {
[viewController release];
[window release];
[super dealloc];
}
#end
This controller handles subview load/removes:
`RootViewController.h`
#import <UIKit/UIKit.h>
#interface RootViewController : UIViewController {
}
- (void) displayView:(int)intNewView;
#end
`RootViewController.m`
#import "RootViewController.h"
#import "ViewController.h"
#implementation RootViewController
UIViewController *currentView;
- (void) displayView:(int)intNewView {
NSLog(#"%i", intNewView);
[currentView.view removeFromSuperview];
[currentView release];
switch (intNewView) {
case 1:
currentView = [[ViewController alloc] initWithNibName:#"View" bundle:nil];
break;
}
[self.view addSubview:currentView.view];
}
- (void)viewDidLoad {
currentView = [[ViewController alloc]
initWithNibName:#"View" bundle:nil];
[self.view addSubview:currentView.view];
[super viewDidLoad];
}
- (void)dealloc {
[currentView release];
[super dealloc];
}
#end
There would be as many case as "detail" ViewControllers I have (right now I have 3 case but this will grow to 10 or more). The purpose of this structure is to easily move from one "section" of the application to another (NavBar controller or TabBar controller do not suit my specific needs).
`ViewController.h`
// Generic View Controller Example
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController {
UIImageView *_image1;
UIImageView *_image2;
NSTimer *_theTimer;
}
#property (nonatomic, retain) IBOutlet UIImageView *image1;
#property (nonatomic, retain) IBOutlet UIImageView *image2;
#property (nonatomic, retain) NSTimer *theTimer;
#end
`ViewController.m`
#import "ViewController.h"
#import "MyAppDelegate.h"
#synthesize image1 = _image1, image2 = _image2, theTimer = _theTimer;
- (void)loadMenu {
[self.theTimer invalidate];
self.theTimer = nil;
MyAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
[appDelegate displayView:2];
}
-(void)setView:(UIView*)aView {
if (!aView){
self.image1 = nil;
self.image2 = nil;
}
[super setView:aView];
}
- (void)viewDidLoad {
//some code
[super viewDidLoad];
}
- (void)viewDidUnload {
self.image1 = nil;
self.image2 = nil;
}
- (void)dealloc {
NSLog(#"dealloc called");
[self.theTimer invalidate];
[self.theTimer release];
[self.image1 release];
[self.image2 release];
[super dealloc];
}
Notice the NSLog in dealloc. This is being called (I can see it in the console) but the memory needed for the nib is not freed (Instruments shows an increase in memory allocation when leaving a section, because a new nib is loaded).
Any help will be greatly appreciated. I have tried a million different things and I cannot get the nibs to unload.
After a million different tries I finally ran into this forum.
It states:
Apparently images assigned in IB are loaded into image views using imageNamed. imageNamed caches the images in a way that makes them unloadable. You could load the images in viewDidLoad with initWithContentsOfFile and then assign them to the views.
Somewhere else I had read that imageNamed is the devil so I'd rather not have my images load that way.
(BTW this is iPhone OS 3.1 I'm using)
What I ended up is leaving the UIImageView intact in IB but with an empty .image value. The modified code is something like:
- (void)viewDidLoad {
NSString *path = [NSString stringWithFormat:#"%#/%#", [[NSBundle mainBundle] resourcePath], #"myImageThatBeforeWasAValueinIB.jpg"];
UIImage *image = [UIImage imageWithContentsOfFile:path];
outlet.image = image;
// do the rest of my stuff as it was
[super viewDidLoad];
}
- (void)dealloc {
outlet.image = nil;
[outlet release], outlet = nil;
[super dealloc];
}
And now everything works like a charm! Memory is recovered when I unload a nib and when I get memory warnings.
So pretty much if you have IBOutlets for UIImageViews and memory is a concern (it always is I guess), you can design all you want in IB and when the time comes to connect them to outlets, remove the image reference in IB and create it from code. IB is really good for laying out your app. It would suck to have to do all that thing by code, but I also found this nice utility that converts nibs to objective c code although I haven't tested it yet.
Did you try setting your outlet variables to nil in dealloc?
You are correctly implementing the setView method, but you are setting your outlet variables to nil in the viewDidUnload method instead of dealloc. As discussed here, you should implement dealloc as follows:
- (void)setView:(UIView *)aView {
if (!aView) { // view is being set to nil
// set outlets to nil, e.g.
self.anOutlet = nil;
}
// Invoke super's implementation last
[super setView:aView];
}
- (void)dealloc {
// release outlets and set outlet variables to nil
[anOutlet release], anOutlet = nil;
[super dealloc];
}
EDIT: if the outlets are UIImageViews, then it may be the case that you need to do
anOutlet.image = nil;
because setting the UIImage’s instance image property should increase the retain count of the UIImage’s instance by 1.