iOS-CAEmitterLayer（粒子效果）

最新推荐文章于 2022-02-15 18:07:07 发布

weixin_34007879

最新推荐文章于 2022-02-15 18:07:07 发布

阅读量76

点赞数

CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/hxwj/p/4664087.html

本文介绍如何利用Core Animation技术创建雪雨效果视图，并通过封装基类简化实现过程。通过自定义粒子发射层（CAEmitterLayer），用户可以轻松地在iOS应用中实现动态的雪景或雨滴效果。同时，展示了如何通过WJCAEmitterLayerView类来进一步封装这些功能，使得开发者能够快速创建出具有视觉吸引力的动态场景。

扩展：https://github.com/lichtschlag/Dazzle

// 创建出Layer
    CAEmitterLayer *emitterLayer = [CAEmitterLayer layer];

     // 显示边框
    emitterLayer.borderWidth = 1;
     // 给定尺寸
    emitterLayer.frame = CGRectMake( 100, 100, 100, 100);
//     emitterLayer.masksToBounds = YES;
     // 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.layer addSublayer:emitterLayer];

    CAEmitterCell *cell = [CAEmitterCell emitterCell];
     // 粒子产生率
    cell.birthRate = 1.f;
     // 粒子生命周期
    cell.lifetime = 120.f;
     // 速度值
    cell.velocity = 10;
     // 速度值得微调值
    cell.velocityRange = 3.f;
     // y轴加速度
    cell.yAcceleration = 2.f;
     // 发射角度(角度越大偏移越大)
    cell.emissionRange = 4.f *M_1_PI;
     // 设置粒子颜色
//     cell.color = [UIColor blackColor].CGColor;
     // 设置图片
    cell.contents = (__bridge id)([UIImage imageNamed: @" test1 "].CGImage);
    emitterLayer.emitterCells = @[cell];

效果图：

例子：下雪下雨的封装

基类：WJCAEmitterLayerView

#import <UIKit/UIKit.h>

@interface WJCAEmitterLayerView : UIView
/* *
*  模仿setter getter方法
*/
- ( void)setEmitterLayer:(CAEmitterLayer *)layer;
- (CAEmitterLayer *)emitterLayer;

/* *
*  显示当前View
*/
- ( void)show;
/* *
*  隐藏当前View
*/
- ( void)hide;

@end

#import " WJCAEmitterLayerView.h "

@interface WJCAEmitterLayerView () {
    CAEmitterLayer *_emitterLayer;
}

@end

@implementation WJCAEmitterLayerView

+ (Class)layerClass {
     return [CAEmitterLayer class];

}

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
     if (self) {
        _emitterLayer = (CAEmitterLayer *)self.layer;
    }
     return self;
}

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

}

- (CAEmitterLayer *)emitterLayer {
     return _emitterLayer;
}

- ( void)show {

}

- ( void)hide {

}

@end

封装下雪下雨view集成基类

下雪：

#import " SnowView.h "

@implementation SnowView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
     if (self) {
        [self initEmitterLayerProperties];
    }
     return self;
}

- ( void)initEmitterLayerProperties {
      // 初始化一些参数
//     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 {
     // 添加 CAEmitterCell
    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 = (__bridge id)([UIImage imageNamed: @" test1 "].CGImage);
    snowflake.color = [UIColor redColor].CGColor;
    snowflake.lifetime = 60.f;
    snowflake.scale = 0.5;
    snowflake.scaleRange = 0.3;
     // 添加动画
    self.emitterLayer.emitterCells = @[snowflake];
}

- ( void)hide {

}

@end

下雨：

#import " RainView.h "

@implementation RainView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
     if (self) {
        [self initEmitterLayerProperties];
    }
     return self;
}

- ( void)initEmitterLayerProperties {
     // 初始化一些参数
    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 {
     // 添加 CAEmitterCell
    CAEmitterCell *snowflake = [CAEmitterCell emitterCell];
    snowflake.birthRate = 25.f;
    snowflake.speed = 10.f;
    snowflake.velocity = 10.f;
    snowflake.velocityRange = 10.f;
    snowflake.yAcceleration = 1000.f;
//     snowflake.emissionRange = 0.5 *M_PI;
//     snowflake.spinRange = 0.25 *M_PI;
    snowflake.contents = (__bridge id)([UIImage imageNamed: @" test1 "].CGImage);
    snowflake.color = [UIColor greenColor].CGColor;
    snowflake.lifetime = 7.f;
    snowflake.scale = 0.2;
    snowflake.scaleRange = 0.f;
     // 添加动画
    self.emitterLayer.emitterCells = @[snowflake];
}

- ( void)hide {

}

@end

调用：

    WJCAEmitterLayerView *snoView = [[SnowView alloc]initWithFrame:CGRectMake( 0, 100,CGRectGetWidth(self.view.bounds), 300)];
    [self.view addSubview:snoView];
    [snoView show];

// snoView.maskView = alpaView;可以让边缘模糊

转载于:https://www.cnblogs.com/hxwj/p/4664087.html