Memory consumption keeps increasing while running application.

Question

Hello all,

I have multiple views in my application with respective view controllers. What I am doing is as follows.

Here is the more illustrative code:

- (void)applicationDidFinishLaunching:(UIApplication *)application
{
  View1Controller *viewController1 = [[View1Controller alloc] initWithnibName:@"View1"];
  View2Controller *viewController2 = [[View2Controller alloc] initWithnibName:@"View2"];
  View3Controller *viewController3 = [[View3Controller alloc] initWithnibName:@"View3"];

  [window addSubview:viewController1.view];
  [window makeKeyAndVisible];
}

In View1Controller file:

For Some Button Action

- (IBAction) goTOView2:(id)sender
{
  iPhoneApplicationAppDelegate *appDelegate = (iPhoneApplicationAppDelegate*) [[UIApplication sharedApplication] delegate];
  [appDelegate.window.superView removeFromSuperview];
  [appDelgate.window addSubview: appDelgate.viewController2.view];
}

Similarly for view3

I am retaining all this three view controller in my application delegate. When I want to switch to other view I have the following code.

Don't go on the syntax errors of the code.

This three view controller has multiple view with their own navigation controller which for pushing and popping different views.

My problem is when I run this application using instrument, I see as I switch from one view to another the memory consumption keeps increasing.

Please help and thanks for that in advance.

Answer 1

Adding and removing views from your app's window is not the recommended way of switching between view controllers. You should be using a UITabBar and letting the UITabBarController handle your view controllers.

The fact that your memory consumption keeps increasing means that you are allocating more objects as your application runs. It probably doesn't have anything to do with the way you're switching views. You're most likely allocating objects and forgetting to release them - causing memory leaks. You should try using the Leaks tool in Instruments to determine which lines of code are causing your problems. (Or post more here!)

Answer 2

The "leaks" tool usually does not help in cases where you see memory slowly grow, these often are not leaks but objects retained unexpectedly.

In the Object Allocation tool, select the "created and still living" option.

Then select a region in the graph where you see more memory being used, when you expect no new memory to be created. Follow that information to see just what is creating objects you are not expecting..

Also, you say you are setting these view controllers as properties. So that means you set them exactly like this in applicationDidFinishLaunching:

self.viewController1 = viewController1;

Right?

Answer 3

This line looks wrong:

[appDelegate.window.superView removeFromSuperview];

What you want is something like:

[viewController1.view removeFromSuperview];

depending on which view you're moving away from.