新建一个ZoomScrollView类，将.h和.m代码复制后，直接在新类中可以直接引用

1 #import <UIKit/UIKit.h>
2
3 @interface ZoomScrollView : UIScrollView<UIScrollViewDelegate>
4 @property (nonatomic,strong) UIImageView* imageView;
5 @property (nonatomic,assign) BOOL isZoom;
6 @end

#import "ZoomScrollView.h"
#define ScreenWidth      CGRectGetWidth([UIScreen mainScreen].applicationFrame)
#define ScreenHeight     CGRectGetHeight([UIScreen mainScreen].applicationFrame)@implementation ZoomScrollView- (id)initWithFrame:(CGRect)frame
{self = [super initWithFrame:frame];if (self) {self.delegate=self;self.frame=CGRectMake(0, 0, ScreenWidth, ScreenHeight);[self initImageView];self.isZoom=NO;}return self;
}-(void)initImageView
{self.imageView=[[UIImageView alloc]init];self.imageView.frame = CGRectMake(0, 0, ScreenWidth , ScreenHeight );//是否能触发手势self.imageView.userInteractionEnabled = YES;[self addSubview:self.imageView];//设置放大倍数self.maximumZoomScale=17;//设置是否显示滚动条self.showsHorizontalScrollIndicator=NO;self.showsVerticalScrollIndicator=NO;//添加双击手势UITapGestureRecognizer* doubleTap=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(didDoubleTap:)];doubleTap.numberOfTapsRequired=2;[self.imageView addGestureRecognizer:doubleTap];}-(void)didDoubleTap:(UIGestureRecognizer*)gesture
{if (self.isZoom){[self setZoomScale:1 animated:YES];self.isZoom = NO;}else{[self setZoomScale:3 animated:YES];self.isZoom = YES;}}#pragma mark - UIScrollViewDelegate
-(UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView
{return self.imageView;
}-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale
{[self setZoomScale:scale animated:YES];}@end

- (void)viewDidLoad
{[super viewDidLoad];ZoomScrollView* abc=[[ZoomScrollView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)];abc.imageView.image=[UIImage imageNamed:@"1.png"];    [self.view addSubview:abc];
}