iOSCoreAnimation动画系列教程（二）：CAKeyFrameAnimation【包会】

 1 #import <Foundation/Foundation.h>
 2 #import <UIKit/UIKit.h>
 3 #import <QuartzCore/QuartzCore.h>
 4 
 5 @protocol ThrowLineToolDelegate;
 6 
 7 @interface ThrowLineTool : NSObject
 8 
 9 @property (nonatomic, assign) id<ThrowLineToolDelegate>delegate;
10 @property (nonatomic, retain) UIView *showingView;
11 
12 + (ThrowLineTool *)sharedTool;
13 
14 /**
15  *  将某个view或者layer从起点抛到终点
16  *
17  *  @param obj    被抛的物体
18  *  @param start  起点坐标
19  *  @param end    终点坐标
20  *  @param height 高度，抛物线最高点比起点/终点y坐标最低(即高度最高)所超出的高度
21  */
22 - (void)throwObject:(UIView *)obj from:(CGPoint)start to:(CGPoint)end
23              height:(CGFloat)height duration:(CGFloat)duration;
24 
25 @end
26 
27 
28 @protocol ThrowLineToolDelegate <NSObject>
29 
30 /**
31  *  抛物线结束的回调
32  */
33 - (void)animationDidFinish;
34 
35 @end

 1 #import "ThrowLineTool.h"
 2 
 3 static ThrowLineTool *s_sharedInstance = nil;
 4 @implementation ThrowLineTool
 5 
 6 + (ThrowLineTool *)sharedTool
 7 {
 8     if (!s_sharedInstance) {
 9         s_sharedInstance = [[[self class] alloc] init];
10     }
11     return s_sharedInstance;
12 }
13 
14 /**
15  *  将某个view或者layer从起点抛到终点
16  *
17  *  @param obj    被抛的物体
18  *  @param start  起点坐标
19  *  @param end    终点坐标
20  *  @param height 高度，抛物线最高点比起点/终点y坐标最低(即高度最高)所超出的高度
21  */
22 - (void)throwObject:(UIView *)obj from:(CGPoint)start to:(CGPoint)end
23              height:(CGFloat)height duration:(CGFloat)duration
24 {
25     self.showingView = obj;
26     //初始化抛物线path
27     CGMutablePathRef path = CGPathCreateMutable();
28     CGFloat cpx = (start.x + end.x) / 2;
29     CGFloat cpy = -height;
30     CGPathMoveToPoint(path, NULL, start.x, start.y);
31     CGPathAddQuadCurveToPoint(path, NULL, cpx, cpy, end.x, end.y);
32     CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
33     animation.path = path;
34     CFRelease(path);
35     CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
36     scaleAnimation.autoreverses = YES;
37     scaleAnimation.toValue = [NSNumber numberWithFloat:(CGFloat)((arc4random() % 4) + 4) / 10.0];
38 
39     CAAnimationGroup *groupAnimation = [CAAnimationGroup animation];
40     groupAnimation.delegate = self;
41     groupAnimation.repeatCount = 1;
42     groupAnimation.duration = duration;
43     groupAnimation.removedOnCompletion = NO;
44     groupAnimation.animations = @[scaleAnimation, animation];
45     [obj.layer addAnimation:groupAnimation forKey:@"position scale"];
46 }
47 
48 - (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
49 {
50     if (self.delegate && [self.delegate respondsToSelector:@selector(animationDidFinish)]) {
51         [self.delegate performSelector:@selector(animationDidFinish) withObject:nil];
52     }
53     self.showingView = nil;
54 }
55 
56 - (void)dealloc
57 {
58     [super dealloc];
59 }
60 
61 @end

 1 - (void)beginThrowing:(UIView *)view
 2 {
 3     ThrowLineTool *tool = [ThrowLineTool sharedTool];
 4     tool.delegate = self;
 5     UIImageView *bagImgView = (UIImageView *)[self viewWithTag:1000];
 6     CGFloat startX = 0;//arc4random() % (NSInteger)CGRectGetWidth(self.frame);
 7     CGFloat startY = 150;//CGRectGetHeight(self.frame);
 8     CGFloat endX = CGRectGetMidX(bagImgView.frame) + 10 - (arc4random() % 50);
 9     CGFloat endY = CGRectGetMidY(bagImgView.frame);
10     CGFloat height = 50 + arc4random() % 40;
11    [tool throwObject:view
12                 from:CGPointMake(startX, startY)
13                   to:CGPointMake(endX, endY)
14               height:height duration:1.6];
15 }