XMG CAKeyFrameAnimation

用贝泽尔曲线描绘了一个路径。然后让CAKeyFrameAnimation的path是这个。就可以描绘出这个曲线路径了

CAKeyframeAnimation*keyFrameAnimation=[CAKeyframeAnimation
animation];

keyFrameAnimation.keyPath=@"position";

keyFrameAnimation.duration=2;
//贝泽尔曲线描绘的路径
keyFrameAnimation.path=_bezierPath.CGPath;
keyFrameAnimation.repeatCount=MAXFLOAT;

[self.singleImageView.layer
addAnimation:keyFrameAnimation
forKey:nil];

#import "DrawView.h"

@interface DrawView()

@property (weak,
nonatomic) IBOutlet
UIImageView *singleImageView;
//@property (weak,nonatomic)UIImageView*imageView;U
@property(nonatomic,strong)UIBezierPath*bezierPath;
@end

@implementation DrawView

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/

-(void)awakeFromNib{

[self
addGestureRecognizer:[[UIPanGestureRecognizer
alloc]initWithTarget:self
action:@selector(panClick:)]];

}

-(void)panClick:(UIPanGestureRecognizer*)pan{

CGPoint currentP=[pan
locationInView:self];
if (pan.state==UIGestureRecognizerStateBegan) {

_bezierPath=[UIBezierPath
bezierPath];

[_bezierPath
moveToPoint:currentP];

_bezierPath.lineWidth=5;

}else
if(pan.state==UIGestureRecognizerStateChanged){

[_bezierPath
addLineToPoint:currentP];
//每次添加线的时候
画一次
[self
setNeedsDisplay];

}else
if(pan.state==UIGestureRecognizerStateEnded){

CAKeyframeAnimation*keyFrameAnimation=[CAKeyframeAnimation
animation];

keyFrameAnimation.keyPath=@"position";

keyFrameAnimation.duration=2;
//贝泽尔曲线描绘的路径
keyFrameAnimation.path=_bezierPath.CGPath;
keyFrameAnimation.repeatCount=MAXFLOAT;

[self.singleImageView.layer
addAnimation:keyFrameAnimation
forKey:nil];
}

// [self setNeedsDisplay];

}

-(void)drawRect:(CGRect)rect
{
[[UIColor
redColor]setStroke];
[self.bezierPath
stroke];
}