三、让我们来“火”一把
通过上面的介绍，我们来应用这些创造一团火，代码示例如下：
@interface ViewController ()
{
CAEmitterLayer * _fireEmitter;//发射器对象
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.view.backgroundColor=[UIColor blackColor];
//设置发射器
_fireEmitter=[[CAEmitterLayer alloc]init];
_fireEmitter.emitterPosition=CGPointMake(self.view.frame.size.width/2,self.view.frame.size.height-20);
_fireEmitter.emitterSize=CGSizeMake(self.view.frame.size.width-100, 20);
_fireEmitter.renderMode = kCAEmitterLayerAdditive;
//发射单元
//火焰
CAEmitterCell * fire = [CAEmitterCell emitterCell];
fire.birthRate=800;
fire.lifetime=2.0;
fire.lifetimeRange=1.5;
fire.color=[[UIColor colorWithRed:0.8 green:0.4 blue:0.2 alpha:0.1]CGColor];
fire.contents=(id)[[UIImage imageNamed:@"Particles_fire.png"]CGImage];
[fire setName:@"fire"];
fire.velocity=160;
fire.velocityRange=80;
fire.emissionLongitude=M_PI+M_PI_2;
fire.emissionRange=M_PI_2;
fire.scaleSpeed=0.3;
fire.spin=0.2;
//烟雾
CAEmitterCell * smoke = [CAEmitterCell emitterCell];
smoke.birthRate=400;
smoke.lifetime=3.0;
smoke.lifetimeRange=1.5;
smoke.color=[[UIColor colorWithRed:1 green:1 blue:1 alpha:0.05]CGColor];
smoke.contents=(id)[[UIImage imageNamed:@"Particles_fire.png"]CGImage];
[fire setName:@"smoke"];
smoke.velocity=250;
smoke.velocityRange=100;
smoke.emissionLongitude=M_PI+M_PI_2;
smoke.emissionRange=M_PI_2;
_fireEmitter.emitterCells=[NSArray arrayWithObjects:smoke,fire,nil];
[self.view.layer addSublayer:_fireEmitter];
}
效果如下：
看到效果了么？这次够炫酷了吧，改改其它属性，尽情的玩吧！
