removeFromSuperview causes my app to crash - iphone

Question

I'm sure this is some stupid mistake, but i'm trying for the past hour to remove a subview from my superview without any success.
On my first view i'm having
UIViewController *helpView = [[[UIViewController alloc] initWithNibName:#"HelpView" bundle:nil] autorelease];
[self.view addSubview:helpView.view];
And then inside helpView i have a button which is connected to an IBAction called "closeHelp" which just does the following:
- (IBAction) closeHelp{
[self.view removeFromSuperview];
}
But this causes my app to crash with EXC_BAS_ACCESS for some weird reason, even those this is inside the HelpView, meaning self.view should be pointed to the correct subview..
Would appreciate your help
Thank you.
Shai.

Answer 1

As Andreas answered, you are trying to remove self.view from its super/parent view.
You basically need to remove the helpView from its parent view.
so it should be
- (IBAction) closeHelp{
[helpView removeFromSuperview];
}
But we dont know what is "helpView" in the above method. As we dont have any handle for it.
So our code should finally look like this.
#define HELP_VIEW_TAG 101 // Give tag of your choice
HelpView *helpView = [[HelpView alloc] initWithNibName:#"HelpView" bundle:nil];
helpView.view.tag = HELP_VIEW_TAG;
[self.view addSubview:helpView.view];
[helpView release];
- (IBAction) closeHelp{
UIView *helpView = [self.view viewWithTag:HELP_VIEW_TAG];
[helpView removeFromSuperview];
}

Answer 2

The self.view does not point to your subview but the root view which your uiviewcontroller manages. You should probably remove only the last object in the subview stack, not the whole view, because now you are removing the whole help view.
Anyway, why do you not present the viewcontroller modally instead of doing this?
[self presentModalViewController:helpView animated:NO/YES];
helpView. modalTransitionStyle = //One of the constants below
UIModalTransitionStyleCoverVertical
UIModalTransitionStyleFlipHorizontal
UIModalTransitionStyleCrossDissolve
UIModalTransitionStylePartialCurl
Usually I am writing self.modalTransitionStyle = // One of the constants
in the viewcontroller which will be presented modally, instead of spreading the code.

Answer 3

You are initializing helpView as a UIViewController.
Make sure you have #import "HelpView.h" (or whatever the helpView .h file is called) in the .h file of the view controller where you are initializing it.
Then, use this code:
HelpView *helpView = [[HelpView alloc] initWithNibName:#"HelpView" bundle:nil];
[self.view addSubview:helpView.view];
That should fix it.

Answer 4

The easiest solution for me eventually was to just define my XIB's file owner as the same class as the parent controller, meaning the parent controller would control both the parent and the subview, which just makes a lot easier. :)

Answer 5

Declare the help view on calss level.
in.h file
#class HelpView;
..
#interface
{
HelpView *helpView;
}
#property(nonatomic,retain)HelpView* helpView;
In.m file
#import "HelpView"
#synthensize helpView;
now add this Code where you want
helpView = [[HelpView alloc] initWithNibName:#"HelpView" bundle:nil];
helpView.view.tag = HELP_VIEW_TAG;
[self.view addSubview:helpView.view];
- (IBAction) closeHelp{
//UIView *helpView = [self.view viewWithTag:HELP_VIEW_TAG];
[helpView removeFromSuperview];
}
-(void)dealloc
{
[helpView release];
}