本文實例為大家分享了iOS實現大雪紛飛動畫的具體代碼，供大家參考，具體內容如下
1.結果展示
美麗的雪花，勾起了多少美好的回憶。
2.制作思路
其實創作這樣一個大學紛飛的場景是十分簡單的，簡單到你看了教程之后想不會都不行。OK，下面國際慣例，講解一下思路吧。
1.創建一個數組用來保存大量的雪花
_imagesArray = [[NSMutableArray alloc] init]; for (int i = 0; i < 1000; ++ i) { UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snow"]]; float x = IMAGE_WIDTH; imageView.frame = CGRectMake(IMAGE_X, -30, x, x); imageView.alpha = IMAGE_ALPHA; [self.view addSubview:imageView]; [_imagesArray addObject:imageView]; }2.使用時鐘（CADisplayLink）來控制下雪，為什么不使用NSTimer呢。其實是可以的，只是（CADisplayLink）刷幀更快一些。
//創建時鐘，并且添加到主循環中CADisplayLink *link = [CADisplayLink displayLinkWithTarget:self selector:@selector(makeSnow)];[link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
3.下雪，就是把數組當做隊列來使用。
每次從數組頭部取出一個雪花并且刪除其在數組中的占位。
讓雪花飄落，通過UIView動畫完成frame，transform等改變。
當動畫完成之后，將取出的雪花再次放進數組的尾部
- (void)makeSnow{ if (_imagesArray.count > 0) { UIImageView *imageView = _imagesArray[0]; [_imagesArray removeObjectAtIndex:0]; [self snowFall:imageView]; }}- (void)snowFall:(UIImageView *)imageView{ [UIView animateWithDuration:10 animations:^{ imageView.frame = CGRectMake(imageView.frame.origin.x, Main_Screen_Height, imageView.frame.size.width, imageView.frame.size.height); imageView.transform = CGAffineTransformMakeScale(0.3, 0.3); imageView.transform = CGAffineTransformRotate(imageView.transform, M_PI); } completion:^(BOOL finished) { float x = IMAGE_WIDTH; imageView.frame = CGRectMake(IMAGE_X, -30, x, x); [_imagesArray addObject:imageView]; }];}3.有代碼有真相
#define IMAGE_X arc4random()%(int)Main_Screen_Width#define IMAGE_ALPHA ((float)(arc4random()%10))/10#define IMAGE_WIDTH arc4random()%20 + 10#define PLUS_HEIGHT Main_Screen_Height/25#define Main_Screen_Height [[UIScreen mainScreen] bounds].size.height#define Main_Screen_Width [[UIScreen mainScreen] bounds].size.width#import "ViewController.h"@interface ViewController ()@property (nonatomic ,strong) NSMutableArray *imagesArray;@property (nonatomic , strong) UIImageView *imageView;@end@implementation ViewController- (void)loadView{ UIImageView *imageView = [[UIImageView alloc]initWithFrame:[UIScreen mainScreen].bounds]; imageView.image = [UIImage imageNamed:@"backgound.jpg"]; imageView.contentMode = UIViewContentModeScaleAspectFill; self.view = imageView;}- (void)viewDidLoad{ [super viewDidLoad]; _imagesArray = [[NSMutableArray alloc] init]; for (int i = 0; i < 1000; ++ i) { UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snow"]]; float x = IMAGE_WIDTH; imageView.frame = CGRectMake(IMAGE_X, -30, x, x); imageView.alpha = IMAGE_ALPHA; [self.view addSubview:imageView]; [_imagesArray addObject:imageView]; } //創建時鐘，并且添加到主循環中 CADisplayLink *link = [CADisplayLink displayLinkWithTarget:self selector:@selector(makeSnow)]; [link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];}- (void)makeSnow{ if (_imagesArray.count > 0) { UIImageView *imageView = _imagesArray[0]; [_imagesArray removeObjectAtIndex:0]; [self snowFall:imageView]; }}- (void)snowFall:(UIImageView *)imageView{ [UIView animateWithDuration:10 animations:^{ imageView.frame = CGRectMake(imageView.frame.origin.x, Main_Screen_Height, imageView.frame.size.width, imageView.frame.size.height); imageView.transform = CGAffineTransformMakeScale(0.3, 0.3); imageView.transform = CGAffineTransformRotate(imageView.transform, M_PI); } completion:^(BOOL finished) { float x = IMAGE_WIDTH; imageView.frame = CGRectMake(IMAGE_X, -30, x, x); [_imagesArray addObject:imageView]; }];}4.Demo也不能少
下載地址：snow
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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