基于CAShapeLayer+CABasicAnimation实

需求：近期项目中有横向柱状图的需求，很容易想到基于CAShapeLayer去实现，在实现柱状图展示动画的过程中有了一些踩坑经历，这里贴出来源代码供大家参考。

showCode:

- (void)drawRectangleLayerWithRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius fillColor:(UIColor)fillColor inView:(UIView)view animate:(BOOL)animate duration:(CGFloat)duration {

    //图形类型的图层

    CAShapeLayer *sLayer = [CAShapeLayer layer];

    sLayer.backgroundColor = fillColor.CGColor;

    sLayer.frame = rect;

    //下面的两行代码是动画需要的属性设置，因为可能会有子视图动画需求

    sLayer.position = rect.origin;

    sLayer.anchorPoint = CGPointZero;

  //添加边框

    sLayer.borderColor = fillColor.CGColor;

    sLayer.borderWidth = 1;

    sLayer.cornerRadius =  cornerRadius;

    [view.layer addSublayer:sLayer];

    if (animate) {

        CABasicAnimation *boundsAnimation = [CABasicAnimation animationWithKeyPath:@"bounds"];

        boundsAnimation.fromValue = [NSValue valueWithCGRect: CGRectMake(rect.origin.x, rect.origin.y, 0, rect.size.height)] ;

        boundsAnimation.toValue = [NSValue valueWithCGRect:rect];

        boundsAnimation.duration = duration;  // 持续时间

        boundsAnimation.removedOnCompletion = NO;

        boundsAnimation.fillMode = kCAFillModeForwards;

        // 动画缓慢的进入，中间加速，然后减速的到达目的地。

        boundsAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

        [sLayer addAnimation:boundsAnimation forKey:@""];

    }

}