UIImageView 点击放大缩小

static CGRect oldframe;

-(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)];

    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];

    }];

}

UIImageView 点击放大缩小

原文：http://www.cnblogs.com/rollrock/p/5416428.html