IOS中实现图片点击全屏预览

最后同样带上一张图片吧，大致是这样子

再给大家分享一则IOS中点击图片后放大的代码

.h文件-----------------------------------------------------------------
#import
@interface ZoomImage : NSObject
/**
 *@brief点击图片放大,再次点击缩小
 *
 *@param oldImageView 头像所在的imageView
 */
+(void)showImage:(UIImageView*)avatarImageView;
@end
.m文件-----------------------------------------------------------------
#import "ZoomImage.h"
static CGRect oldframe;
@implementation ZoomImage
+(void)showImage:(UIImageView*)avatarImageView
{
 UIImage *image =avatarImageView.image;
 // 获得根窗口
 UIWindow *window =[UIApplication sharedApplication].keyWindow;
 UIView *backgroundView =[[UIView alloc]initWithFrame:CGRectMake(0, 0, WIDTH, HEIGHT)];
 oldframe =[avatarImageView convertRect:avatarImageView.bounds toView:window];
 backgroundView.backgroundColor =[UIColor blackColor];
 backgroundView.alpha =0.5;
 UIImageView *imageView =[[UIImageView alloc]initWithFrame:oldframe];
 imageView.image =image;
 imageView.tag =1;
 [backgroundView addSubview:imageView];
 [window addSubview:backgroundView];
 //点击图片缩小的手势
 UITapGestureRecognizer *tap =[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideImage:)];
 [backgroundView addGestureRecognizer:tap];
 [UIView animateWithDuration:0.3 animations:^{
  imageView.frame =CGRectMake(0,([UIScreen mainScreen].bounds.size.height-image.size.height*[UIScreen mainScreen].bounds.size.width/image.size.width)/2, [UIScreen mainScreen].bounds.size.width, image.size.height*[UIScreen mainScreen].bounds.size.width/image.size.width);
  backgroundView.alpha =1;
 }];
}
+(void)hideImage:(UITapGestureRecognizer *)tap{
 UIView *backgroundView =tap.view;
 UIImageView *imageView =(UIImageView *)[tap.view viewWithTag:1];
 [UIView animateWithDuration:0.3 animations:^{
  imageView.frame =oldframe;
  backgroundView.alpha =0;  
 } completion:^(BOOL finished) {
  [backgroundView removeFromSuperview];
 }];
}