爲什麼我的翻轉動畫沒有改變到另一種觀點？

Question

這是我翻轉動畫的代碼，我使用2次是viewMain和viewStart

- (IBAction)readyBtn:(id)sender { 
    [UIView beginAnimations:nil context:nil]; 
    [UIView setAnimationDuration:1.0]; 
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:[self view] cache:YES]; 
    [[self view] addSubview:viewStart]; 
    [UIView commitAnimations]; 
} 

- (IBAction)startBtn:(id)sender { 
    [UIView beginAnimations:nil context:nil]; 
    [UIView setAnimationDuration:1.0]; 
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:[self view] cache:YES]; 
    [viewStart removeFromSuperview]; 
    [UIView commitAnimations]; 
} 

後，我運行它，我viewMain被翻轉到同一viewMain，它不能改變翻蓋viewStart。如何解決它？

Answer 1

(IBAction)readyBtn:(id)sender { 
    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationDuration:1]; 
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:viewMain cache:YES]; 
    viewStart.frame = viewMain.bounds; 
    [viewMain addSubview:viewStart]; 
    [UIView commitAnimations];