iOS 全屏看大图

-(void)showImage:(UIImageView *)avatarImageView{
    
    UIImage *image=avatarImageView.image;
    
    UIWindow *window=[UIApplication sharedApplication].keyWindow;
    
    UIView *backgroundView=[[UIView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
    //小图frame
    oldframe =[avatarImageView convertRect:avatarImageView.bounds toView:window];
    
    backgroundView.backgroundColor=[UIColor blackColor];
    
    backgroundView.alpha=0;
    
    UIImageView *imageView=[[UIImageView alloc]initWithFrame:oldframe];
    
    imageView.image=image;
    
    imageView.tag=1;
    
    [backgroundView addSubview:imageView];
    
    [window addSubview:backgroundView];
    
    
    
    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;
        
    } completion:^(BOOL finished) {
        
        
        
    }];
    
}

-(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];
        
    }];
    
}