Button Action Issue in IOS - ios6

Question

This is the code i have used.
In View Controller A:
- (void)viewDidLoad
{
[super viewDidLoad];
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setFrame:CGRectMake(50, 50, 70, 40)];
[button setTitle:#"Next View" forState:UIControlStateNormal];
[button addTarget:self action:#selector(nextView) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
}
-(void) nextView
{
SecondviewController *secondView = [[SecondviewController alloc] init];
[self.view addSubview:secondView.view];
}
In View Controller B:
- (void)viewDidLoad
{
[super viewDidLoad];
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setFrame:CGRectMake(50, 50, 70, 40)];
[button setTitle:#"Previous View" forState:UIControlStateNormal];
[button addTarget:self action:#selector(previousView) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
}
-(void) previousView
{
[self.view removeFromSuperview];
}
Issue: When i click the button in the view controller B, its not switching back to the view controller A...

Answer 1

You are not switching viewControllers, you are taking the view from viewController B and adding it as a subview to viewController A.
Here:
SecondviewController *secondView = [[SecondviewController alloc] init];
[self.view addSubview:secondView.view];
You need to navigate to the new view Controller... Replace it with this for example
SecondviewController *secondViewController = [[SecondviewController alloc] init];
[self presentViewController:secondViewController animated:YES completion:NIL];
(it's best to include 'controller' when naming controllers to avoid confusion with their views)
Then to return, you need to dismiss the presented viewcontroller...
In ViewControllerB replace this:
[self.view removeFromSuperview];
With
[[self presentingViewController] dismissViewControllerAnimated:YES completion:NIL];
This is sending a message back from the presented viewController - viewController B - to the presenting viewController, viewControllerA which does the actual dismissing.

Answer 2

instead of adding a the second subview to the first subview, you need to present or push the view controller in the stack. You are just simply adding it as a subview.
SecondviewController *secondView = [[SecondviewController alloc] init];
[self presentViewController:secondView animated:NO completion:nil];
In the second view controller when you dismiss it you can just simply dismiss/pop it from the stack.
[self dismissViewControllerAnimated:YES];