使用带粒子效果的 CAEmitterLayer

1.用CAEmitterLayer产生粒子效果

2.封装CAEmitterLayer

3.封装下雪、下雨的粒子效果控件

一、用CAEmitterLayer产生粒子效果

- (void)emitterLayer {

// 1.创建出Layer

CAEmitterLayer *emitterLayer = [CAEmitterLayer layer];

//
显示边框

emitterLayer.borderWidth = 1.f;

//
给定尺寸

emitterLayer.frame = CGRectMake(100,
100, 100, 100);

//emitterLayer.mask = YES;不超过范围

//
发射点

emitterLayer.emitterPosition = CGPointMake(0,0);

//
发射模式

emitterLayer.emitterMode =kCAEmitterLayerSurface;

//
发射形状

emitterLayer.emitterShape =kCAEmitterLayerLine;

//
添加layer

[self.view.layeraddSublayer:emitterLayer];

// 2.创建粒子

CAEmitterCell *cell = [CAEmitterCell emitterCell];

//
粒子产生率

cell.birthRate = 10.f;

//
粒子生命周期

cell.lifetime = 10.f;

//
速度值

cell.velocity = 10;

//
速度值的微调值

cell.velocityRange = 3.f;

// y轴加速度

cell.yAcceleration = 2.f;

//
发射角度

cell.emissionRange = 4.f *
M_1_PI;

//
设置粒子颜色

cell.color = [UIColorblackColor].CGColor;

//
设置图片

cell.contents = (__bridgeid)([UIImage imageNamed:@"snow"].CGImage);

//
让CAEmitterCell与CAEmitterLayer产生关联

emitterLayer.emitterCells = @[cell];

}

二、封装CAEmitterLayer

@interface CAEmitterLayerView :
UIView

/**

* 模仿setter.getter方法

*/

- (void)setEmitterLayer:(CAEmitterLayer *)layer;

- (CAEmitterLayer *)emitterLayer;

/**

* 显示出当前view

*/

- (void)show;

/**

* 隐藏当前view

*/

- (void)hide;

@end

二、封装 CAEmitterLayer

1.替换CAEmitterLayer成UIView子类的backedLayer

2.将CAEmitterLayer封装的类作为“抽象”父类

#import "CAEmitterLayerView.h"

@interface CAEmitterLayerView () {

//由于 CAEmitterLayer的参数非常多，采用这种小技巧，设置set,get方法

CAEmitterLayer *_emitterLayer;

}

@end

@implementation CAEmitterLayerView

+ (Class)layerClass {//必须要写这个，否则新建返回layer,不是 CAEmitterLayer

return [CAEmitterLayerclass];

}

- (instancetype)initWithFrame:(CGRect)frame {

self = [superinitWithFrame:frame];

if (self) {

_emitterLayer = (CAEmitterLayer *)self.layer;

}

return
self;

}

- (void)show {

}

- (void)hide {

}

- (void)setEmitterLayer:(CAEmitterLayer *)layer {

_emitterLayer = layer;

}

- (CAEmitterLayer *)emitterLayer {

return_emitterLayer;

}

@end

- (void)viewDidLoad {

[superviewDidLoad];

CAEmitterLayerView *layerView = [[CAEmitterLayerView alloc]initWithFrame:CGRectMake(100,100,100,100)];

NSLog(@"%@", layerView.layer);

}

三、封装下雪、下雨的粒子效果控件

#import "CAEmitterLayerView.h"

@interface RainView :CAEmitterLayerView

@end

#import "RainView.h"

@implementation RainView

- (instancetype)initWithFrame:(CGRect)frame {

self = [superinitWithFrame:frame];

if (self) {

//初始化设置

[selfsetup];

}

return
self;

}

- (void)setup {

self.emitterLayer.masksToBounds =YES;

self.emitterLayer.emitterShape =kCAEmitterLayerLine;

self.emitterLayer.emitterMode =kCAEmitterLayerSurface;

self.emitterLayer.emitterSize =self.frame.size;

self.emitterLayer.emitterPosition =CGPointMake(self.bounds.size.width /2.f, -
20);

}

- (void)show {

//
配置

CAEmitterCell *rainflake = [CAEmitterCell emitterCell];

rainflake.birthRate =25.f;

rainflake.speed =10.f;

rainflake.velocity =10.f;

rainflake.velocityRange =10.f;

rainflake.yAcceleration =1000.f;

rainflake.contents = (__bridgeid)([UIImage imageNamed:@"rain"].CGImage);

rainflake.color = [UIColorblackColor].CGColor;

rainflake.lifetime =7.f;

rainflake.scale =0.2f;

rainflake.scaleRange =0.f;

//
添加动画

self.emitterLayer.emitterCells =@[rainflake];

}

@end

封装 CAEmitterLayer

@interface SnowView :CAEmitterLayerView

@end

#import "SnowView.h"

@implementation SnowView

- (instancetype)initWithFrame:(CGRect)frame {

self = [superinitWithFrame:frame];

if (self) {

//初始化设置

[selfsetup];

}

return
self;

}

- (void)setup {

self.emitterLayer.masksToBounds =YES;

self.emitterLayer.emitterShape =kCAEmitterLayerLine;

self.emitterLayer.emitterMode =kCAEmitterLayerSurface;

self.emitterLayer.emitterSize =self.frame.size;

self.emitterLayer.emitterPosition =CGPointMake(self.bounds.size.width /2.f, -
20);

}

- (void)show {

//
配置

CAEmitterCell *snowflake = [CAEmitterCell emitterCell];

snowflake.birthRate =1.f;

snowflake.speed =10.f;

snowflake.velocity =2.f;

snowflake.velocityRange =10.f;

snowflake.yAcceleration =10.f;

snowflake.emissionRange =0.5 *M_PI;

snowflake.spinRange =0.25 *M_PI;

snowflake.contents = (__bridgeid)([UIImage imageNamed:@"snow"].CGImage);

snowflake.color = [UIColorredColor].CGColor;

snowflake.lifetime =60.f;

snowflake.scale =0.5;

snowflake.scaleRange =0.3;

//
添加动画

self.emitterLayer.emitterCells =@[snowflake];

}

@end

封装 CAEmitterLayer

#import "CAEmitterLayerView.h"

#import "SnowView.h"

#import "RainView.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[superviewDidLoad];

UIImageView *alphaView1 = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,100,100)];

alphaView1.image = [UIImage imageNamed:@"alpha"];

UIImageView *alphaView2 = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,100,100)];

alphaView2.image = [UIImage imageNamed:@"alpha"];

//
添加下雪效果

CAEmitterLayerView *snowView = [[SnowView alloc]initWithFrame:CGRectMake(100,100,100,100)];

snowView.maskView = alphaView1;//加maskView，效果不突兀

[self.viewaddSubview:snowView];

[snowViewshow];

//
添加下雨效果

CAEmitterLayerView *rainView = [[RainView alloc]initWithFrame:CGRectMake(100,210,100,100)];

rainView.maskView = alphaView2;

[self.viewaddSubview:rainView];

[rainViewshow];

}

@end