iOS伪转场动画

   <h2><strong>iOS伪转场动画</strong></h2>    <ul>     <li> <p>通过modal进行转场，设置 modalTransitionStyle 为 UIModalTransitionStyleCrossDissolve ,设置 modalPresentationStyle 为 UIModalPresentationOverFullScreen</p> </li>    </ul>    <h2><strong>图片放大缩小的效果</strong></h2>    <p>外部只需要传入一个外部的 UIImageView 即可</p>    <p>1.创建一个 UIImageView 和一个 CGRect 来保存图片信息和图片frame信息。</p>    <p>使用 - (CGRect)convertRect:(CGRect)rect toView:(nullable UIView *)view; 方法来获取图片的相对位置。</p>    <p>2.视图将要出现时做动画效果</p>    <pre>  <code class="language-objectivec">- (void)viewWillAppear:(BOOL)animated{          [super viewWillAppear:animated];          [UIView animateWithDuration:AnimationTime animations:^{                 //这里可以自由发挥了          self.view.backgroundColor = [UIColor greenColor];self.currentIV.frame = CGRectMake(0, 0, 200, 200);   self.currentIV.center = CGPointMake(self.view.center.x, 200);          } completion:^(BOOL finished) {          }];      }</code></pre>    <p>3.返回的点击事件处理</p>    <pre>  <code class="language-objectivec">- (void)back{      [UIView animateWithDuration:AnimationTime animations:^{          if ([self.type isEqualToString:@"vv"]) {              self.view.center = CGPointMake(self.view.center.x, self.view.bounds.size.height*1.5);          }else {              self.currentIV.frame = self.oldFrame;              self.view.backgroundColor = [UIColor clearColor];          }      } completion:^(BOOL finished) {          [self dismissViewControllerAnimated:NO completion:nil];      }];    }</code></pre>    <p>4.就这样，效果就出来啦</p>    <p style="text-align:center"><img src="https://simg.open-open.com/show/a0ab63fb609ce21267e61c806178a65d.gif"></p>    <h2><strong>Boss直聘动画效果</strong></h2>    <p>用的是截屏的方法来实现背景缩小后置的效果</p>    <p>1.在当前 UIViewController 用一个 UIImageView 来保存截图</p>    <pre>  <code class="language-objectivec">-(UIImage *)screenImageWithSize:(CGSize )imgSize{      UIGraphicsBeginImageContext(imgSize);      CGContextRef context = UIGraphicsGetCurrentContext();        AppDelegate * app = (AppDelegate *)[UIApplication sharedApplication].delegate; //获取app的appdelegate，便于取到当前的window用来截屏      [app.window.layer renderInContext:context];        UIImage * img = UIGraphicsGetImageFromCurrentImageContext();      UIGraphicsEndImageContext();      return img;  }</code></pre>    <p>2.在下一个VC创建一个减方法，在当前VC中使用</p>    <pre>  <code class="language-objectivec">[self presentViewController:vc animated:NO completion:nil];        [UIView animateWithDuration:0.3 animations:^{      //当前VC下截图的缩小效果          self.screenshot.bounds = CGRectMake(50, 50, SCREEN.width - 100, SCREEN.height - 100);      } completion:^(BOOL finished) {      //这就是减方法 =_= 动画结束时，改变背景块的frame          [vc changeBigView];      }];</code></pre>    <p>3.在下一个VC返回时，当前VC的截图视图移除。</p>    <pre>  <code class="language-objectivec">[weakSelf.screenshot removeFromSuperview];</code></pre>    <p>4.这样，BOSS直聘的动画效果就出现了。</p>    <p style="text-align:center"><img src="https://simg.open-open.com/show/ea357f70dbb8f6e3bdd048f939fd3f23.gif"></p>    <h3><strong>按以上思路，就可以实现一些简单常见的动画效果^0^</strong></h3>    <p> </p>    <p>来自：http://www.jianshu.com/p/18549d27fe0e</p>    <p> </p>