Why won't this simple view switching project work? - xcode

Question

I'm in the process of learning how to write apps in Xcode. I'm using a book to guide me. Unfortunately the book is written with guides to Xcode 3 and I'm using Xcode 4.
Now so far there haven't been any problems, but this project doesn't work, and I simply don't get it, because it seems to make pretty good sense.
The project's goal is to use a view controller to switch between three views.
Could anyone please take a look and see what I did wrong?
Here is the entire project: http://www.2shared.com/file/CKO6ACzg/MultipleViews.html
PS: I know that as it is now the views will be stacked on top off each other and that the view isn't being cleared when you click a new button.

Answer 1

MultipleViewsViewController.h should be:
#import <UIKit/UIKit.h>
#class FirstViewController;
#class SecondViewController;
#class ThirdViewController;
#interface MultipleViewsViewController : UIViewController {
IBOutlet FirstViewController *firstViewController;
IBOutlet SecondViewController *secondViewController;
IBOutlet ThirdViewController *thirdViewController;
}
//#property (nonatomic, retain) FirstViewController *firstViewController;
//#property (nonatomic, retain) SecondViewController *secondViewController;
//#property (nonatomic, retain) ThirdViewController *thirdViewController;
-(IBAction)loadFirstView:(id)sender;
-(IBAction)loadSecondView:(id)sender;
-(IBAction)loadThirdView:(id)sender;
#end
MultipleViewsViewController.m should be:
#import "MultipleViewsViewController.h"
#import "FirstViewController.h"
#import "SecondViewController.h"
#import "ThirdViewController.h"
#implementation MultipleViewsViewController
//#synthesize firstViewController;
//#synthesize secondViewController;
//#synthesize thirdViewController;
-(IBAction)loadFirstView:(id)sender{
[secondViewController.view removeFromSuperview];
[thirdViewController.view removeFromSuperview];
[self.view insertSubview:firstViewController.view atIndex:0];
}
-(IBAction)loadSecondView:(id)sender{
[firstViewController.view removeFromSuperview];
[thirdViewController.view removeFromSuperview];
[self.view insertSubview:secondViewController.view atIndex:0];
}
-(IBAction)loadThirdView:(id)sender{
[firstViewController.view removeFromSuperview];
[secondViewController.view removeFromSuperview];
[self.view insertSubview:thirdViewController.view atIndex:0];
}
-(void)dealloc{
[firstViewController release];
[secondViewController release];
[thirdViewController release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
firstViewController = [[FirstViewController alloc] init];
secondViewController = [[SecondViewController alloc] init];
thirdViewController = [[ThirdViewController alloc] init];
[self loadFirstView:nil];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
Connect your buttons (which you haven't done in your project, which also might be the issue) and you're done.