DismissModalView ControllerAnimated函数不解除视图

我想用 dismissModalViewController:Animated: 拒绝我的观点,但不管我怎么努力,这并不是拒绝它。您可以看到我在 hideSplash 方法位于底部。如果有人能帮忙,我将不胜感激。我的代码发布在下面:

#import "SplashViewController.h"

@implementation SplashViewController

- (void) didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

- (void) viewDidUnload {

}

- (void) dealloc {
    [super dealloc];
}

-(void) showSplash {
    modalViewController = [[UIViewController alloc] init];
    modalViewController.view = modelView;
    [self presentModalViewController:modalViewController animated:NO];
    [activityIndicator startAnimating ];
    //[self bigcalculation];
    //[self performSelector:@selector(hideSplash) withObject:nil afterDelay:2.0];
}

- (void) viewDidAppear:(BOOL)animated {
    NSLog(@"View Did Appear");
    [self bigcalculation];
}

- (void) bigcalculation {
    NSLog(@"Big Calc Start");
    for (int i = 0; i <= 648230; i++) {
        for (int j = 0; j <= 1200; j++) {

        }
    }
    NSLog(@"Big Calc End");
    [self performSelector:@selector(hideSplash) withObject:nil];
}

- (void) hideSplash {
    NSLog(@"Hide");
    //[self dismissModalViewControllerAnimated:NO];
    //[[self parentViewController] dismissModalViewControllerAnimated:YES];
    [[self modalViewController] dismissModalViewControllerAnimated:YES];
    NSLog(@"End Hide");
}

@end