iOS动画——弹窗动画（pop动画）

    用pop动画简单实现弹窗的缩放和渐变，感觉这个动画常用，就写一下博客

   pop动画是Facebook推出的动画引擎，请自行到GitHub上搜索下载拖拽导入xcode项目中。

  更多pop动画使用和原理可网上搜索学习

  本处只简单介绍代码开发使用,紧以弹窗效果为思路。

    

  1. 控制器导入头文件 #import "POP.h"

  2.创建弹窗透明黑色背景

- (void)createBlackView {

    self.blackView                 = [[UIView alloc] initWithFrame:self.contentView.bounds];
    self.blackView.backgroundColor = [UIColor blackColor];
    self.blackView.alpha           = 0;
    [self addSubview:self.blackView];

    [UIView animateWithDuration:0.3f animations:^{

        self.blackView.alpha = 0.25f;
    }];
}

3.创建白色上面的白色view,并加上所需的控件，给白色的messageView做pop动画效果，

  代码如下

// 执行动画 改变透明度
 POPBasicAnimation  *alpha = [POPBasicAnimation animationWithPropertyNamed:kPOPViewAlpha];
 alpha.toValue             = @(1.f);
 alpha.duration            = 0.3f;
 [self.messageView pop_addAnimation:alpha forKey:nil];
 // 缩放回弹
 POPSpringAnimation *scale = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerScaleXY];
 scale.fromValue           = [NSValue valueWithCGSize:CGSizeMake(1.75f, 1.75f)];
 scale.toValue             = [NSValue valueWithCGSize:CGSizeMake(1.f, 1.f)];
 scale.dynamicsTension     = 1000;
 scale.dynamicsMass        = 1.3;
 scale.dynamicsFriction    = 10.3;
 scale.springSpeed         = 20;
 scale.springBounciness    = 15.64;
 scale.delegate            = self;
 [self.messageView.layer pop_addAnimation:scale forKey:nil];

4.弹窗消失的思路代码

- (void)removeViews {

    [UIView animateWithDuration:0.2f animations:^{

        self.blackView.alpha       = 0.f;
        self.messageView.alpha     = 0.f;
        self.messageView.transform = CGAffineTransformMakeScale(0.75f, 0.75f);

    } completion:^(BOOL finished) {

        [self removeFromSuperview];
    }];
}