[Objective-C开发]|iOS 雪花动画与跑马灯 ios|动画|Objective-C成长之路

这篇是接着上一篇, 关于动画效果的收集篇, 这篇介绍了跑马灯动画以及下落雪花动画, 请看, 话说最近怎么不在状态呢, 好伤感(囧~).
上一篇 - iOS 仿YY直播心形动画 & 烟花动画
跑马灯效果演示这里贴出使用代码, 详细请下载Demo查看
下载即用~ 快餐 - -Star鼓励

下载后, 在VC中这样使用, 当然Demo中也有体现

- (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. self.view.backgroundColor = [UIColor blackColor]; XTScrollLabelView *drawMarqueeView= [[XTScrollLabelView alloc] initWithFrame:CGRectMake(0, 0, 250.f, 20)]; drawMarqueeView.delegate= self; drawMarqueeView.marqueeDirection= FromLeftType; drawMarqueeView.center= self.view.center; [self.view addSubview:drawMarqueeView]; [drawMarqueeView addContentView:[self createLabelWithText:@"夏天是个很好的季节, 而夏天然后是简书的推荐作者, 喜欢分享!" textColor:[self randomColor]]]; [drawMarqueeView startAnimation]; }- (UILabel *)createLabelWithText:(NSString *)text textColor:(UIColor *)textColor {NSString *string = [NSString stringWithFormat:@" %@ ", text]; CGFloat width = [string widthWithStringAttribute:@{NSFontAttributeName : [UIFont systemFontOfSize:14.f]}]; UILabel*label= [[UILabel alloc] initWithFrame:CGRectMake(0, 0, width, 20)]; label.font= [UIFont systemFontOfSize:14.f]; label.text= string; label.textColor= textColor; return label; } - (UIColor *)randomColor {return [UIColor colorWithRed:[self randomValue] green:[self randomValue] blue:[self randomValue] alpha:1]; } - (CGFloat)randomValue {return arc4random() % 256 / 255.f; } - (void)drawMarqueeView:(XTScrollLabelView *)drawMarqueeView animationDidStopFinished:(BOOL)finished { [drawMarqueeView stopAnimation]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [drawMarqueeView addContentView:[self createLabelWithText:[self randomString] textColor:[self randomColor]]]; [drawMarqueeView startAnimation]; }); } - (NSString *)randomString {NSArray *array = @[@"人帅", @"勤劳", @"年轻", @"刻苦", @"开玩笑", @"都是我编的, 前面的别跑"]; return array[arc4random() % array.count]; }

![演示](http://upload-images.jianshu.io/upload_images/1506501-60f6dae4324b1ba1.gif?imageMogr2/auto-orient/strip) 雪花动画代码演示 – 在ViewDidLoad中这样写, 注释已经很详细

// 创建粒子Layer CAEmitterLayer *snowEmitter = [CAEmitterLayer layer]; // 粒子发射位置 snowEmitter.emitterPosition = CGPointMake(120,0); // 发射源的尺寸大小 snowEmitter.emitterSize= self.view.bounds.size; // 发射模式 snowEmitter.emitterMode= kCAEmitterLayerSurface; // 发射源的形状 snowEmitter.emitterShape= kCAEmitterLayerLine; // 创建雪花类型的粒子 CAEmitterCell *snowflake= [CAEmitterCell emitterCell]; // 粒子的名字 snowflake.name = @"snow"; // 粒子参数的速度乘数因子 snowflake.birthRate = 20.0; snowflake.lifetime= 120.0; // 粒子速度 snowflake.velocity= 10.0; // 粒子的速度范围 snowflake.velocityRange = 10; // 粒子y方向的加速度分量 snowflake.yAcceleration = 2; // 周围发射角度 snowflake.emissionRange = 0.5 * M_PI; // 子旋转角度范围 snowflake.spinRange = 0.25 * M_PI; snowflake.contents= (id)[[UIImage imageNamed:@"snow"] CGImage]; // 设置雪花形状的粒子的颜色 snowflake.color= [[UIColor whiteColor] CGColor]; snowflake.redRange= 1.5f; snowflake.greenRange = 2.2f; snowflake.blueRange= 2.2f; snowflake.scaleRange = 0.6f; snowflake.scale= 0.7f; snowEmitter.shadowOpacity = 1.0; snowEmitter.shadowRadius= 0.0; snowEmitter.shadowOffset= CGSizeMake(0.0, 0.0); // 粒子边缘的颜色 snowEmitter.shadowColor= [[UIColor whiteColor] CGColor]; // 添加粒子 snowEmitter.emitterCells = @[snowflake]; // 将粒子Layer添加进图层中 [self.view.layer addSublayer:snowEmitter]; // 形成遮罩 UIImage *image= [UIImage imageNamed:@"alpha"]; _layer= [CALayer layer]; _layer.frame= (CGRect){CGPointZero, self.view.bounds.size}; _layer.contents= (__bridge id)(image.CGImage); _layer.position= self.view.center; snowEmitter.mask= _layer;