该类存放在CAAnimation.h文件中

Super class

@interface CAKeyframeAnimation : CAPropertyAnimation

Attribute

• 属性值数组

/* An array of objects providing the value of the animation function for
 * each keyframe. */
@property(nullable, copy) NSArray *values;

• 动画路径

/* An optional path object defining the behavior of the animation
 * function. When non-nil overrides the `values' property. Each point
 * in the path except for `moveto' points defines a single keyframe for
 * the purpose of timing and interpolation. Defaults to nil. For
 * constant velocity animation along the path, `calculationMode' should
 * be set to `paced'. Upon assignment the path is copied. */
@property(nullable) CGPathRef path;

源代码

/* An optional array of `NSNumber' objects defining the pacing of the
 * animation. Each time corresponds to one value in the `values' array,
 * and defines when the value should be used in the animation function.
 * Each value in the array is a floating point number in the range
 * [0,1]. */

@property(nullable, copy) NSArray<NSNumber *> *keyTimes;

/* An optional array of CAMediaTimingFunction objects. If the `values' array
 * defines n keyframes, there should be n-1 objects in the
 * `timingFunctions' array. Each function describes the pacing of one
 * keyframe to keyframe segment. */

@property(nullable, copy) NSArray<CAMediaTimingFunction *> *timingFunctions;

/* The "calculation mode". Possible values are `discrete', `linear',
 * `paced', `cubic' and `cubicPaced'. Defaults to `linear'. When set to
 * `paced' or `cubicPaced' the `keyTimes' and `timingFunctions'
 * properties of the animation are ignored and calculated implicitly. */

@property(copy) NSString *calculationMode;

/* For animations with the cubic calculation modes, these properties
 * provide control over the interpolation scheme. Each keyframe may
 * have a tension, continuity and bias value associated with it, each
 * in the range [-1, 1] (this defines a Kochanek-Bartels spline, see
 * http://en.wikipedia.org/wiki/Kochanek-Bartels_spline).
 *
 * The tension value controls the "tightness" of the curve (positive
 * values are tighter, negative values are rounder). The continuity
 * value controls how segments are joined (positive values give sharp
 * corners, negative values give inverted corners). The bias value
 * defines where the curve occurs (positive values move the curve before
 * the control point, negative values move it after the control point).
 *
 * The first value in each array defines the behavior of the tangent to
 * the first control point, the second value controls the second
 * point's tangents, and so on. Any unspecified values default to zero
 * (giving a Catmull-Rom spline if all are unspecified). */

@property(nullable, copy) NSArray<NSNumber *> *tensionValues;
@property(nullable, copy) NSArray<NSNumber *> *continuityValues;
@property(nullable, copy) NSArray<NSNumber *> *biasValues;

/* Defines whether or objects animating along paths rotate to match the
 * path tangent. Possible values are `auto' and `autoReverse'. Defaults
 * to nil. The effect of setting this property to a non-nil value when
 * no path object is supplied is undefined. `autoReverse' rotates to
 * match the tangent plus 180 degrees. */

@property(nullable, copy) NSString *rotationMode;

@end