UIScrollView缩放图片操作

 1 #import "CXBViewController.h"
 2 
 3 @interface CXBViewController () <UIScrollViewDelegate>
 4 {
 5     UIImageView *_imageView;
 6 }
 7 @end
 8 
 9 @implementation CXBViewController
10 
11 - (void)viewDidLoad
12 {
13     [super viewDidLoad];
14     // 当设置scrollView为全屏时，直接用self.view.bounds
15     UIScrollView *scroll = [[UIScrollView alloc] initWithFrame:self.view.bounds];
16     [self.view addSubview:scroll];
17     // 设置UIImageView,UIImageView的初始化用initWithImage，那么UIImageView的大小和图片的一样
18     UIImage *image = [UIImage imageNamed:@"minion"];
19     _imageView = [[UIImageView alloc] initWithImage:image];
20     [scroll addSubview:_imageView];
21     scroll.contentSize = image.size;
22     // 设置代理
23     scroll.delegate = self;
24     // 设置最大缩放比例
25     scroll.maximumZoomScale = 2.0;
26     // 设置最小缩放比例
27     scroll.minimumZoomScale = 0.2;
28 }
29 
30 #pragma mark 这个方法返回的控件就能够进行缩放操作
31 - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
32 {
33     return _imageView;
34 }
35 @end