Описание тега cabasicanimation

CABasicAnimation is the most basic explicit animation in Core Animation ( core-animation). By simply specifying a from value, a to value and optionally other parameters like the duration you can have hardware accelerated animations in just a few lines of code.

Animations are created with the key path that they should be animating like

CABasicAnimation *moveAnimation = 
↪   [CABasicAnimation animationWithKeyPath:@"position"];

After creating a new animation it is configured. Common configurations include setting the values to animate to and from, setting a duration and changing the timing function (how the animation is animated). Note that Core Graphics values have to be wrapped into NSValue objects when used.

// valueWithCGPoint: for iOS and valueWithPoint: for OS X.
[moveAnimation setFromValue:[NSValue valueWithCGPoint:myStartPoint]]; 
[moveAnimation setToValue:[NSValue valueWithCGPoint:myEndPoint]]; 
[moveAnimation setDuration:3.0]; // 3 seconds
[moveAnimation setTimingFunction:
↪   [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];

When the animation is configured it is applied by adding it to the layer that should animate. Note that the key parameter when adding the animation has nothing to do with the key path of the animation. It is only used to reference the animation after is has been added to the layer.

[myLayer addAnimation:moveAnimation 
               forKey:@"myMoveAnimation"];

Note that explicitly animating a property like this doesn't change the value of the actual property and after the animation finishes it will remove itself and the layer will jump back to the state it had before the animation. To also change the value of the property, explicitly change the value in the same before or after adding the animation to the layer.

One powerful feature even custom properties can be animated the same way (by specifying the key path).

Basic animations is available on both ios (since iOS 2.0) and osx (since OS X 10.5 "Leopard") and is part of the quartz-core framework.