1、创建UIScrollView，设置属性：
scrollView.delegate=self;
scrollView.contentSize=CGSizeMake(SCREEN_WIDTH,SCREEN_HEIGHT);
scrollView.showsVerticalScrollIndicator = NO;
scrollView.showsHorizontalScrollIndicator = NO;
scrollView.pagingEnabled=NO;
scrollView.bounces=NO;
scrollView.minimumZoomScale=0.5;
scrollView.maximumZoomScale=2;
2、指定要缩放的视图组件
- (UIView*)viewForZoomingInScrollView:(UIScrollView*)scrollView{
return self.imageView;
}
3、确保图片在视图中间
- (void)scrollViewDidZoom:(UIScrollView*)scrollView {
UIImageView *imgView =(UIImageView*)[self.imgViewList objectAtIndex:self.whichIndex];
if(imgView.frame.size.width>=scrollView.size.width&& imgView.size.height>= scrollView.frame.size.height){
imgView.frame=CGRectMake(0,0, imgView.size.width,imgView.size.height);
}
if(imgView.frame.size.width< scrollView.frame.size.width){
imgView.frame=CGRectMake((scrollView.frame.size.width-imgView.size.width)/2, imgView.origin.y, imgView.size.width, imgView.size.height);
}
if(imgView.size.height< scrollView.size.height){
imgView.frame = CGRectMake(imgView.frame.origin.x, (scrollView.frame.size.height-imgView.frame.size.height)/2, imgView.frame.size.width, imgView.frame.size.height);
}
}
4、如果同时还有图片浏览功能的话，可以用UIScrollView嵌套UIScrollView，再嵌套UIImageView
