CATransition 应用代码 View Transitions

-(void)applicationDidFinishLaunching:(UIApplication *)application

{

// Create the two views to transition between, and add them to our containerView. We'll hide the second one

// until we are ready to transition to it.

UIImage *image1 = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"image1.jpg" ofType:nil]];

view1 = [[UIImageView alloc] initWithImage:image1];

UIImage *image2 = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"image2.jpg" ofType:nil]];

view2 = [[UIImageView alloc] initWithImage:image2];

view2.hidden = YES;

[containerView addSubview:view1];

[containerView addSubview:view2];

transitioning = NO;

}

-(void)dealloc

{

[containerView release];

[view1 release];

[view2 release];

[super dealloc];

}

-(void)performTransition

{

// First create a CATransition object to describe the transition

CATransition *transition = [CATransition animation];

// Animate over 3/4 of a second

transition.duration = 0.75;

// using the ease in/out timing function

transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

// Now to set the type of transition. Since we need to choose at random, we'll setup a couple of arrays to help us.

NSString *types[4] = {kCATransitionMoveIn, kCATransitionPush, kCATransitionReveal, kCATransitionFade};

NSString *subtypes[4] = {kCATransitionFromLeft, kCATransitionFromRight, kCATransitionFromTop, kCATransitionFromBottom};

int rnd = random() % 4;

transition.type = types[rnd];

if(rnd < 3) // if we didn't pick the fade transition, then we need to set a subtype too

{

transition.subtype = subtypes[random() % 4];

}

// Finally, to avoid overlapping transitions we assign ourselves as the delegate for the animation and wait for the

// -animationDidStop:finished: message. When it comes in, we will flag that we are no longer transitioning.

transitioning = YES;

transition.delegate = self;

// Next add it to the containerView's layer. This will perform the transition based on how we change its contents.

[containerView.layer addAnimation:transition forKey:nil];

// Here we hide view1, and show view2, which will cause Core Animation to animate view1 away and view2 in.

view1.hidden = YES;

view2.hidden = NO;

// And so that we will continue to swap between our two images, we swap the instance variables referencing them.

UIImageView *tmp = view2;

view2 = view1;

view1 = tmp;

}

-(void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag

{

transitioning = NO;

}

-(IBAction)nextTransition:(id)sender

{

if(!transitioning)

{

[self performTransition];

}

}