Databases
StackOverflow2013
Postsdbo
POAdding subviews to a view programatically: where should memory be managed?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POAdding subviews to a view programatically: where should memory be managed?
    primarykey
    data
    text
    <p>I've read <a href="http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/BasicViewControllers/BasicViewControllers.html#//apple_ref/doc/uid/TP40007457-CH101-SW19" rel="nofollow">http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/BasicViewControllers/BasicViewControllers.html#//apple_ref/doc/uid/TP40007457-CH101-SW19</a> but I'm still not completely clear on how this works.</p> <pre><code>@property (nonatomic, retain) UIButton *startButton; @property (nonatomic, retain) UITextView *infoTextView; </code></pre> <p>This is a view controller displayed in a tab bar</p> <pre><code>- (void)loadView { UIView *newView = [[UIView alloc] init]; //self.startButton and addSubivew retains the button obect; retain count = 2 UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; //autorelases self.startButton = button; [newView addSubview:startButton]; //addSubview retains infoTextView; self.infoTextview retains; retain count: 2 self.infoTextView = [[[UITextView alloc] initWithFrame:CGRectMake(0.0, 0.0, 280.0, 270.0)] autorelease]; //autoreleased [newView addSubview:infoTextView]; //View controller retains the view hierarchy self.view = newView; [newView release]; } //customization of the button and textview (text, frame, center, target-action etc) - (void)viewDidLoad { [super viewDidLoad]; [self loadStartButton]; [self loadTextView]; } //because these have retain properties, they are released through nil - (void)viewDidUnload { self.startButton = nil; self.infoTextView = nil; //retain counts - 1 [super viewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [startButton release]; [infoTextView release]; //retain counts -1 [super dealloc]; } </code></pre> <p>My question is this: should the UIView objects have retain counts of two? The way I see it is that <strong>the view controller retains the UIView object, and the viewController.view also retains the UIView object</strong> (through adding subviews). Is this the correct way to look at it conceptually? Because then my viewController is also managing objects owned by its .view property.</p> <p>However, I'm not sure if both viewDidUnload and dealloc are called in the case of low memory situations. Am I releasing them correctly or setting up a memory leak?</p> <p>(any comments about putting code in the wrong place would be helpful as well)</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USLouis
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload