视图切换效果, slide, fade, flip

FadeAnimation.m

- (void) fadeOut: (id) sender
{
	CGContextRef context = UIGraphicsGetCurrentContext();
	[UIView beginAnimations:nil context:context];
	[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
	[UIView setAnimationDuration:1.0];
	[[self.view viewWithTag:999] setAlpha:0.0f];
	[UIView commitAnimations];
	self.navigationItem.rightBarButtonItem = BARBUTTON(@"Fade In", @selector(fadeIn:));
}

- (void) fadeIn: (id) sender
{
	CGContextRef context = UIGraphicsGetCurrentContext();
	[UIView beginAnimations:nil context:context];
	[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
	[UIView setAnimationDuration:1.0];
	[[self.view viewWithTag:999] setAlpha:1.0f];
	[UIView commitAnimations];
	self.navigationItem.rightBarButtonItem = BARBUTTON(@"Fade Out", @selector(fadeOut:));
}

modalTransitionStyle.m

- (void) info
{
	int segment = [(UISegmentedControl *)self.navigationItem.titleView selectedSegmentIndex];
	int styles[3] = {
		UIModalTransitionStyleCoverVertical, 
		UIModalTransitionStyleCrossDissolve, 
		UIModalTransitionStyleFlipHorizontal
	};
	InfoViewController *ivc = [[[InfoViewController alloc] init] autorelease];
	ivc.modalTransitionStyle = styles[segment];
	[self presentModalViewController:ivc animated:YES];
}

SwipAnimation.m

- (void) swap: (id) sender
{
	// hide the button
	self.navigationItem.rightBarButtonItem = nil;
	
	UIView *frontObject = [[self.view subviews] objectAtIndex:2];
	UIView *backObject = [[self.view subviews] objectAtIndex:1];
	
	CGContextRef context = UIGraphicsGetCurrentContext();
	[UIView beginAnimations:nil context:context];
	[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
	[UIView setAnimationDuration:1.0];
	
	frontObject.alpha = 0.0f;
	backObject.alpha = 1.0f;
	frontObject.transform = CGAffineTransformMakeScale(0.25f, 0.25f);
	backObject.transform = CGAffineTransformIdentity;
	[self.view exchangeSubviewAtIndex:1 withSubviewAtIndex:2];

	[UIView setAnimationDelegate:self];
	[UIView setAnimationDidStopSelector:@selector(animationFinished:)];
	[UIView commitAnimations];
	
}