单击图片放大，浏览图片细节，之后再单击回到原始页面，
如果在浏览细节时候，双击图片 会局部放大，也可以双手拖拽放大，
newImage.gif
代码参考
#import “TransImageTool.h”
#define kSCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)
#define kSCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)
#define kMaxZoom 3
@interface TransImageTool ()
@property (nonatomic, assign) CGFloat width;
@property (nonatomic, assign) CGFloat height;
@property (nonatomic, assign) BOOL isTwiceTaping;
@property (nonatomic, assign) BOOL isDoubleTapingForZoom;
@property (nonatomic, assign) CGFloat currentScale;
@property (nonatomic, assign) CGFloat offsetY;
@property (nonatomic, assign) CGFloat touchX;
@property (nonatomic, assign) CGFloat touchY;
@property (nonatomic, strong) UIImageView *transImageView;
@property (nonatomic, strong) UIScrollView *scrollView;
@property (nonatomic, strong) UIView *backView;
@property (nonatomic, strong) UIButton *userBtn ;
@property (nonatomic, strong) UIView *userBtnContainer ;
@end
static CGRect oldframe;
@implementation TransImageTool
– (void)showImage:(UIImageView *)avatarImageView{
UIImage *image = avatarImageView.image;
UIWindow *window = [UIApplication sharedApplication].keyWindow;
oldframe = [avatarImageView convertRect:avatarImageView.bounds toView:window];
UIImageView *imageView = [[UIImageView alloc]initWithFrame:oldframe];
imageView.image = image;
self.transImageView = imageView;
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, kSCREEN_WIDTH, kSCREEN_HEIGHT)];
scrollView.delegate = self;
scrollView.backgroundColor = [UIColor blackColor];
scrollView.maximumZoomScale = 5.0;
CGFloat ratio = _width / _height * kSCREEN_HEIGHT / kSCREEN_WIDTH;
CGFloat min = MIN(ratio, 1.0);
scrollView.minimumZoomScale = min;
self.scrollView = scrollView;
UITapGestureRecognizer *onetap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideImage:)];
[self.scrollView addGestureRecognizer:onetap];
[self.scrollView addSubview:imageView];
UITapGestureRecognizer *tapImgViewTwice = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapImgViewHandleTwice:)];
tapImgViewTwice.numberOfTapsRequired = 2;
tapImgViewTwice.numberOfTouchesRequired = 1;
[scrollView addGestureRecognizer:tapImgViewTwice];
//如果双击失败就单击
[onetap requireGestureRecognizerToFail:tapImgViewTwice];
[window addSubview:self.scrollView];
CGFloat imageViewX = 0;
CGFloat imageViewY = (kSCREEN_HEIGHT – image.size.height*kSCREEN_WIDTH/image.size.width) / 2;
CGFloat imageViewW = kSCREEN_WIDTH;
CGFloat imageViewH = image.size.height * kSCREEN_WIDTH/image.size.width;
[UIView animateWithDuration:0.3
animations:^
{
imageView.frame = CGRectMake(imageViewX, imageViewY, imageViewW, imageViewH);
}
completion:^(BOOL finished)
{
}];
}
– (void)hideImage:(UITapGestureRecognizer*)tap
{
UIView *backgroundView = tap.view;
self.userBtnContainer.alpha = 0;
[UIView animateWithDuration:0.3
animations:^
{
self.transImageView.frame = oldframe;
self.scrollView.alpha = 0;
}
completion:^(BOOL finished)
{
[backgroundView removeFromSuperview];
[self.scrollView removeFromSuperview];
[self.userBtnContainer removeFromSuperview];
}];
}
#pragma mark – UIScrollViewDelegate –
-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
{
self.currentScale = scale;
}
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
return self.transImageView;
}
-(void)scrollViewDidZoom:(UIScrollView *)scrollView
{
CGFloat xcenter = scrollView.center.x;
CGFloat ycenter = scrollView.center.y;
xcenter = scrollView.contentSize.width > kSCREEN_WIDTH?scrollView.contentSize.width / 2 : xcenter;
ycenter = scrollView.contentSize.height > kSCREEN_HEIGHT ?scrollView.contentSize.height / 2 : ycenter;
if(_isDoubleTapingForZoom)//是否是双击放大的
{
if (_touchX>0 && _touchY>0)
{
//点击在图片上
CGFloat transformX = _touchX * kMaxZoom;
CGFloat transformY = _touchY * kMaxZoom;
CGFloat contentW = scrollView.contentSize.width;
CGFloat contentH = scrollView.contentSize.height;
if (transformX + kSCREEN_WIDTH *.5>=contentW)
{
//右边太大。
transformX = kSCREEN_WIDTH*(kMaxZoom-1);
}
else
{
if (transformX-kSCREEN_WIDTH *.5 < 0)
{//左边太小
transformX = 0;
}
else
{
transformX = transformX-kSCREEN_WIDTH *0.5;
}
}
//计算Y
//Y的放大比例跟图片的本身有关，需要从新计算内容的高度和屏幕的尺寸关系
int maxCount = contentH /([UIScreen mainScreen].bounds.size.height);
if (maxCount >= 1)
{
//智能移动到中心
if (transformY-contentH *0.5 < 0)
{
//上边太小，智能移动到边界
transformY = 0;
}
else
{
if (transformY +kSCREEN_HEIGHT *.5 > contentH) {
//下边太大，智能移动到边界
transformY = contentH – kSCREEN_HEIGHT;
}
else
{
transformY = transformY – kSCREEN_HEIGHT *.5;
}
}
}
else
{
if (transformY-contentH *0.5 < 0)
{
//上边太小，智能移动到边界
transformY = 0;
}
else
{
//下边太大，智能移动到边界
transformY = ycenter – kSCREEN_HEIGHT*0.5;
}
}
[scrollView setContentOffset:CGPointMake(transformX, transformY)];
}
else
{
//默认放大位置
[scrollView setContentOffset:CGPointMake(xcenter- kSCREEN_WIDTH *.5, ycenter – kSCREEN_HEIGHT*0.5)];
}
}
[self.transImageView setCenter:CGPointMake(xcenter, ycenter)];
_touchY = 0;
_touchX = 0;
}
-(void)tapImgViewHandleTwice:(UIGestureRecognizer *)sender{
_touchX = [sender locationInView:self.transImageView].x;
_touchY = [sender locationInView:self.transImageView].y;
if (_touchY >CGRectGetHeight(self.transImageView.frame))
{
//如果大于最大的就是在图片外面，默认放大
_touchY = 0;
}
if(_isTwiceTaping)//双击
{
return;
}
_isTwiceTaping = YES;
if(_currentScale > 1.0)
{
_currentScale = 1.0;
[_scrollView setZoomScale:1.0 animated:YES];
}
else
{
_isDoubleTapingForZoom = YES;
_currentScale = kMaxZoom;
[_scrollView setZoomScale:kMaxZoom animated:YES];
}
_isDoubleTapingForZoom = NO;
//延时做标记判断，使用户点击3次时的单击效果不生效。
[self performSelector:@selector(twiceTaping) withObject:nil afterDelay:0.65];
}
-(void)twiceTaping{
_isTwiceTaping = NO;
}
//是否添加其他按钮
– (void)addTooBtnView
{
UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 20, kSCREEN_WIDTH, 80)];
containerView.backgroundColor = [UIColor clearColor];
self.userBtnContainer = containerView;
// [window addSubview:containerView];
/*添加button*/
UIButton *userBtnright = [UIButton buttonWithType:UIButtonTypeSystem];
userBtnright.frame =CGRectMake(kSCREEN_WIDTH – 100, 0, 60, 30);
[userBtnright setTitle:@”正确” forState:UIControlStateNormal];
[userBtnright setBackgroundColor:[UIColor blueColor]];
self.userBtn = userBtnright;
//[containerView addSubview:userBtnright];
/*添加button*/
UIButton *userBtnerror = [UIButton buttonWithType:UIButtonTypeSystem];
userBtnerror.frame =CGRectMake(kSCREEN_WIDTH – 170, 0, 60, 30);
[userBtnerror setTitle:@”错误” forState:UIControlStateNormal];
[userBtnerror setBackgroundColor:[UIColor blueColor]];
self.userBtn = userBtnerror;
//[containerView addSubview:userBtnerror];
}
-(void)dealloc
{
NSLog(@”dealloc”);
}
@end
