只能以一种方式切换视图，无法切换回，sigabort错误

Question

I'm trying to build an iphone app that plays a video then switches view to an info page after. The user can then switch back to the original view before the video plays after reading the info page. I can get the first switch to happen but not the second for some reason. I get a sigabort error that highlights this in the AppDelegate:

    return UIApplicationMain(argc, argv, nil, NSStringFromClass([videoPlayAppDelegate class]));

Here is my code for the first switch...

videoPlayViewController.h

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>
#import "View2.h"

@interface videoPlayViewController : UIViewController
<MPMediaPickerControllerDelegate, UIAlertViewDelegate>
{
    MPMoviePlayerController *moviePlayer;
}
@property (strong, nonatomic) MPMoviePlayerController *moviePlayer;
-(IBAction) playMovie;

@end

videoPlayViewController.m

#import "videoPlayViewController.h"

@implementation videoPlayViewController
@synthesize moviePlayer;

-(void)playMovie
{
    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] 
                                         pathForResource:@"sample" ofType:@"mov"]];
    moviePlayer =  [[MPMoviePlayerController alloc]
                    initWithContentURL:url];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayBackDidFinish:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:moviePlayer];

    moviePlayer.controlStyle = MPMovieControlStyleDefault;
    moviePlayer.shouldAutoplay = NO;
    [self.view addSubview:moviePlayer.view];
    [moviePlayer setFullscreen:YES animated:YES];
    [moviePlayer.view setTransform:CGAffineTransformMakeRotation(M_PI / 2)]; 
}

- (void) moviePlayBackDidFinish:(NSNotification*)notification {
    MPMoviePlayerController *player = [notification object];
    [[NSNotificationCenter defaultCenter] 
     removeObserver:self
     name:MPMoviePlayerPlaybackDidFinishNotification
     object:player];

    if ([player
         respondsToSelector:@selector(setFullscreen:animated:)])
    {
        NSLog(@"This method is working");
        View2 *second =[[View2 alloc] initWithNibName:nil bundle:nil];


        [self presentModalViewController:second animated:YES];

    }

    //[player.view removeFromSuperview];
}

Here's how I switch back...

View2.h

#import <UIKit/UIKit.h>
#import "videoPlayViewController.h"

@interface View2 : UIViewController

-(IBAction) goBack;

@end

View2.m

#import "View2.h"

@interface View2 ()

@end

@implementation View2

-(IBAction) goBack 
{
  //Figure this out
    videoPlayViewController *map =[[videoPlayViewController alloc] initWithNibName:@"videoPlayViewController" bundle:nil];

    [self presentModalViewController:map animated:YES];


}

Answer 1

That's not "going back", that's going on to a different instance of what you already had.

The inverse of presentModalViewController: is dismissModalViewControllerAnimated: (although, if you check the docs, they're both deprecated) so to get rid of something you've presented as modal, you need to dismiss it.