delegate

 1 //
 2 //  ViewController.m
 3 //  11-1UiscrollViewdelegate
 4 //
 5 //  Created by zjj on 15/5/13.
 6 //  Copyright (c) 2015年 zjj. All rights reserved.
 7 //
 8 
 9 #import "ViewController.h"
10 
11 @interface ViewController () <UIScrollViewDelegate>
12 {
13     UIImageView *_imgView;
14 }
15 @end
16 
17 @implementation ViewController
18 
19 - (void)viewDidLoad {
20     [super viewDidLoad];
21     UIScrollView *scroView = [[UIScrollView alloc]init];
22     scroView.frame = self.view.bounds;
23     [self.view addSubview:scroView];
24     
25     UIImage *img = [UIImage imageNamed:@"11.jpg"];
26     _imgView = [[UIImageView alloc]initWithImage:img];
27     [scroView addSubview:_imgView];
28     
29     scroView.contentSize = img.size;
30     scroView.delegate = self;
31     scroView.minimumZoomScale = 0.2;
32     scroView.maximumZoomScale = 2;
33     
34 }
35 
36 - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
37 {
38     return _imgView;
39 }
40 
41 @end
原文地址:https://www.cnblogs.com/zhangdashao/p/4499210.html