(CABasicAnimation)基本动画

(CABasicAnimation)基本动画

###基本动画相关属性

• fromValue:keyPath 相应属性的初始值
• byValue:keyPath相应属性的中间值
• toValue:keyPath相应属性的结束值

动画过程说明

• 随着动画的进行，在长度为duration的持续时间内，keyPath相应属性的值从fromValue渐渐地变为toValue;
• KeyPath内容是CALayer的可动Animatable画属性
• 若是fillMode=KCAFillModeForwards同时removedOnComletion=NO，那么在动画执行完毕后，图层会保持显示动画执行后的状态。但在实质上，图层的属性值仍是动画执行前的初始值，并无真正被改变。

##一、平移 二、缩放 三、旋转

• 平移


    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.translation.x"];
    animation.toValue = @320;
    animation.duration = 1;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.fillMode = kCAFillModeForwards;
    animation.removedOnCompletion = NO;
    
    [self.view.layer addAnimation:animation forKey:@"animation"];

###缩放

CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
    animation.toValue = @2;
    animation.duration = 0.25;
    animation.repeatCount = 1;
    animation.autoreverses = YES;
    
    [self.view.layer addAnimation:animation forKey:@"animation"];

###旋转 *旋转

- (CAAnimation *)rotationAnimation {
  CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    animation.byValue = @( -2 * M_PI);//正数表示按照顺时针旋转，负数为逆时针方向旋转
    animation.duration = 2.0;
    animation.fillMode = kCAFillModeForwards;
    animation.removedOnCompletion = NO;
    animation.autoreverses = YES;
    animation.repeatCount = HUGE_VALF; //  HUGE_VALF 最大浮点数，表示无限次重复
    
    return animation;
}