CAEmitterLayer *snowEmitter = [CAEmitterLayer layer];  //例子发射位置  snowEmitter.emitterPosition = CGPointMake(120,20);  //发射源的尺寸大小  snowEmitter.emitterSize = CGSizeMake(self.view.bounds.size.width * 20, 20);  //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 = 1.0;  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:@"DazFlake"] CGImage];  //设置雪花形状的粒子的颜色  snowflake.color = [[UIColor colorWithRed:0.200 green:0.258 blue:0.543 alpha:1.000] CGColor];    //创建星星形状的粒子  CAEmitterCell *snowflake1 = [CAEmitterCell emitterCell];  //粒子的名字  snowflake1.name = @"snow";  //粒子参数的速度乘数因子  snowflake1.birthRate = 1.0;  snowflake1.lifetime = 120.0;  //粒子速度  snowflake1.velocity =10.0;  //粒子的速度范围  snowflake1.velocityRange = 10;  //粒子y方向的加速度分量  snowflake1.yAcceleration = 2;  //周围发射角度  snowflake1.emissionRange = 0.5 * M_PI;  //子旋转角度范围  snowflake1.spinRange = 0.25 * M_PI;  //粒子的内容和内容的颜色  snowflake1.contents = (id)[[UIImage imageNamed:@"DazStarOutline"] CGImage];  snowflake1.color = [[UIColor colorWithRed:0.600 green:0.658 blue:0.743 alpha:1.000] CGColor];    snowEmitter.shadowOpacity = 1.0;  snowEmitter.shadowRadius = 0.0;  snowEmitter.shadowOffset = CGSizeMake(0.0, 1.0);  //粒子边缘的颜色  snowEmitter.shadowColor = [[UIColor redColor] CGColor];    snowEmitter.emitterCells = [NSArray arrayWithObjects:snowflake,snowflake1,nil];  [self.view.layer insertSublayer:snowEmitter atIndex:0];  // Do any additional setup after loading the view

ios 烟花 火焰 雨水 雪花等特效属性