iOS动画实现雨花与樱花特效

@interface XMWeatherView ()@property(nonatomic,strong) CAEmitterLayer *sunshineEmitterLayer;@property(nonatomic,strong) CAEmitterLayer *rainDropEmitterLayer;@property(nonatomic,strong) UIImageView *backgroundView;@end

#pragma mark - 下雨特效-(void)addRainningEffect{  self.backgroundView.image=[UIImage imageNamed:@"rainning.jpeg"];  //粒子发射器图层  self.rainDropEmitterLayer=[CAEmitterLayer layer];  //粒子发射器位置  _rainDropEmitterLayer.emitterPosition=CGPointMake(100, -30);  //粒子发射器的范围  _rainDropEmitterLayer.emitterSize=CGSizeMake(self.bounds.size.width*4, 0);  //发射模式  _rainDropEmitterLayer.emitterMode=kCAEmitterLayerOutline;  //粒子模式  _rainDropEmitterLayer.emitterShape=kCAEmitterLayerLine;  //创建粒子  CAEmitterCell *emitterCell=[CAEmitterCell emitterCell];  //设置粒子内容  emitterCell.contents=(__bridge id)([UIImage imageNamed:@"42-Raindrop"].CGImage);  //设置粒子缩放比例  emitterCell.scale=0.9;  //缩放范围  emitterCell.scaleRange=0.5;  //每秒粒子产生数量  emitterCell.birthRate=130;  //粒子生命周期  emitterCell.lifetime=5;  //粒子透明速度  emitterCell.alphaSpeed=-0.1;  //粒子速度  emitterCell.velocity=280;  emitterCell.velocityRange=100;  //设置发射角度  emitterCell.emissionLongitude=-M_PI;//  emitterCell.emissionRange=M_PI;  //设置粒子旋转角速度//  emitterCell.spin=M_PI_4;  //设置layer阴影  _rainDropEmitterLayer.shadowOpacity=1.0;  //设置圆角  _rainDropEmitterLayer.shadowRadius=2;  //设置偏移  _rainDropEmitterLayer.shadowOffset=CGSizeMake(1, 1);  //设置颜色  _rainDropEmitterLayer.shadowColor=[UIColor whiteColor].CGColor  ;  //设置layer的粒子  _rainDropEmitterLayer.emitterCells=@[emitterCell];  _rainDropEmitterLayer.transform=CATransform3DMakeRotation(-M_PI/4, 0, 0, 1);  [self.layer addSublayer:_rainDropEmitterLayer];}