CAEmitterLayer发出触摸事件随机不必要的颗粒(CAEmitterLayer emits

我试图建立一个CAEmitterLayer做出纸屑效果，我碰到两个问题：

每当我设置的birthRate在我的细胞东西非零启动动画我得到随机放置在屏幕上的细胞，通常动画乱舞，然后发射器继续后正常发出。
每当emitterCells是在画面绘制的东西，任何时候我触摸屏幕，发射吸引emitterCells中存在的时间（看似）随机的（貌似）随机位置。在发射器没有什么是绑定到任何触摸事件（即我不是故意画上的触摸事件的任何东西），但该层是在具有多个嵌入式视图的视图。我摸越多，细胞出现。

这是我设立的发射器，然后启动和停止它的代码（一旦我叫停止功能，然后轻敲屏幕停火创造新的随机元素）：

- (void)setupConfetti
{
    self.confettiLayer = [CAEmitterLayer layer];
    [self.view.layer addSublayer:self.confettiLayer];
    [self.view.layer setNeedsDisplay];

    self.confettiLayer.emitterPosition = CGPointMake(1024.0/2,-50.0);
    self.confettiLayer.emitterSize = CGSizeMake(1000.0, 10.0);
    self.confettiLayer.emitterShape = kCAEmitterLayerLine; 
    self.confettiLayer.renderMode =kCAEmitterLayerUnordered;

    CAEmitterCell *confetti = [CAEmitterCell emitterCell];

    confetti1.contents =  (id)[[UIImage imageNamed:@"confetti.png"] CGImage];

    confetti.emissionLongitude = M_PI;
    confetti.emissionLatitude = 0;
    confetti.lifetime = 5;
    confetti.birthRate = 0.0;
    confetti.velocity = 125;
    confetti.velocityRange = 50;
    confetti.yAcceleration = 50;
    confetti.spin = 0.0;
    confetti.spinRange = 10;
    confetti.name = @"confetti1";

    self.confettiLayer.emitterCells = [NSArray arrayWithObjects:confetti, nil];
}

要启动纸屑：

- (void)startConfettiAnimation
{
    [self.confettiLayer setValue:[NSNumber numberWithInt:10.0] forKeyPath:@"emitterCells.confetti.birthRate"];
}

并停止它：

- (void)stopConfettiAnimation
{
    [self.confettiLayer setValue:[NSNumber numberWithInt:0.0] forKeyPath:@"emitterCells.confetti.birthRate"];
}

同样，一旦它被启动，随机元素的初始乱舞之后，这个工作得很好：通常一切动画，当出生率后设置为零，它优雅地结束。这似乎只是响应触摸事件，我不知道为什么。我试着加入emitterLayer到不同的视图，该视图上禁用用户交互，然后将其作为主视图的子视图，而且似乎没有工作。

任何帮助/洞察力，将不胜感激！

谢谢，山姆

Answer 1:

我知道这是旧的文章，但我也有这个问题。 Jackslash回答得好在这篇文章： iOS的7 CAEmitterLayer产卵颗粒不适当

您需要设置BEGINTIME您的发射层上在当前时间与CACurrentMediaTime开始（）。这似乎发生，我们有问题，因为发射器在过去已经开始。

emitter.beginTime = CACurrentMediaTime();

Answer 2:

难道你不检查，看看是否粒子发射像Wenderlich例如阿图尔Ozieranski贴？我不只要检查到位看到了一倍。

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [fireView setEmitterPositionFromTouch: [touches anyObject]];
    [fireView setIsEmitting:YES];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [fireView setIsEmitting:NO];
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    [fireView setIsEmitting:NO];
}
-(void)setIsEmitting:(BOOL)isEmitting
{
    //turn on/off the emitting of particles
    [fireEmitter setValue:[NSNumber numberWithInt:isEmitting?200:0] forKeyPath:@"emitterCells.fire.birthRate"];
}

Answer 3:

.h文件中

 #import <UIKit/UIKit.h>

    @interface DWFParticleView : UIView

    -(void)setEmitterPositionFromTouch: (CGPoint*)t;
    -(void)setIsEmitting:(BOOL)isEmitting;

    @end

.m文件

  #import "DWFParticleView.h"
    #import <QuartzCore/QuartzCore.h>

    @implementation DWFParticleView
    {
        CAEmitterLayer* fireEmitter; //1
    }

    -(void)awakeFromNib
    {
        //set ref to the layer
        fireEmitter = (CAEmitterLayer*)self.layer; //2
        //configure the emitter layer
        fireEmitter.emitterPosition = CGPointMake(50, 50);
        fireEmitter.emitterSize = CGSizeMake(10, 10);

        CAEmitterCell* fire = [CAEmitterCell emitterCell];
        fire.birthRate = 0;
        fire.lifetime = 1.5;
        fire.lifetimeRange = 0.3;
        fire.color = [[UIColor colorWithRed:255 green:255 blue:255 alpha:0.1] CGColor];
        fire.contents = (id)[[UIImage imageNamed:@"Particles_fire.png"] CGImage];
        [fire setName:@"fire"];

        fire.velocity =5;
        fire.velocityRange = 20;
        fire.emissionRange = M_PI_2;

        fire.scaleSpeed = 0.1;
        fire.spin = 0.5;

        fireEmitter.renderMode = kCAEmitterLayerAdditive;

        //add the cell to the layer and we're done
        fireEmitter.emitterCells = [NSArray arrayWithObject:fire];

    }

    + (Class) layerClass //3
    {
        //configure the UIView to have emitter layer
        return [CAEmitterLayer class];
    }

    -(void)setEmitterPositionFromTouch: (CGPoint*)t
    {
        //change the emitter's position
        fireEmitter.emitterPosition = (*t);
    }

    -(void)setIsEmitting:(BOOL)isEmitting
    {
        //turn on/off the emitting of particles
        [fireEmitter setValue:[NSNumber numberWithInt:isEmitting?100:0] forKeyPath:@"emitterCells.fire.birthRate"];
    }


    @end

我用此代码为创建自定义视图和发射触摸颗粒
下面是关于触控颗粒排放的调用语句

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint p =  [[touches anyObject] locationInView:self.view];
     [fireView setEmitterPositionFromTouch: &p];
     [fireView setIsEmitting:YES];

}