IOS 单张图片全屏预览

 1 //
 2 //  ViewController.m
 3 //  XWZoomImageView
 4 //
 5 //  Created by xiao on 15/11/13.
 6 //  Copyright © 2015年 xiao. All rights reserved.
 7 //
 8 
 9 #import "ViewController.h"
10 
11 @interface ViewController ()<UIScrollViewDelegate>
12 @property (weak, nonatomic) IBOutlet UIImageView *picView;
13 @property (weak, nonatomic) UIScrollView *scrollView;
14 @property (weak, nonatomic) UIImageView *lastImageView;
15 @property (nonatomic, assign)CGRect originalFrame;
16 @property (nonatomic, assign)BOOL isDoubleTap;
17 @end
18 
19 @implementation ViewController
20 
21 - (void)viewDidLoad {
22     [super viewDidLoad];
23     
24     self.picView.userInteractionEnabled = YES;
25     //添加单击手势
26     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(showZoomImageView:)];
27 
28     [self.picView addGestureRecognizer:tap];
29     
30 }
31 
32 -(void)showZoomImageView:(UITapGestureRecognizer *)tap
33 {
34     if (![(UIImageView *)tap.view image]) {
35         return;
36     }
37     //scrollView作为背景
38     UIScrollView *bgView = [[UIScrollView alloc] init];
39     bgView.frame = [UIScreen mainScreen].bounds;
40     bgView.backgroundColor = [UIColor blackColor];
41     UITapGestureRecognizer *tapBg = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapBgView:)];
42     [bgView addGestureRecognizer:tapBg];
43     
44     UIImageView *picView = (UIImageView *)tap.view;
45     
46     UIImageView *imageView = [[UIImageView alloc] init];
47     imageView.image = picView.image;
48     imageView.frame = [bgView convertRect:picView.frame fromView:self.view];
49     [bgView addSubview:imageView];
50     
51     [[[UIApplication sharedApplication] keyWindow] addSubview:bgView];
52     
53     self.lastImageView = imageView;
54     self.originalFrame = imageView.frame;
55     self.scrollView = bgView;
56     //最大放大比例
57     self.scrollView.maximumZoomScale = 1.5;
58     self.scrollView.delegate = self;
59     
60     [UIView animateWithDuration:0.5 animations:^{
61         CGRect frame = imageView.frame;
62         frame.size.width = bgView.frame.size.width;
63         frame.size.height = frame.size.width * (imageView.image.size.height / imageView.image.size.width);
64         frame.origin.x = 0;
65         frame.origin.y = (bgView.frame.size.height - frame.size.height) * 0.5;
66         imageView.frame = frame;
67     }];
68 }
69 
70 -(void)tapBgView:(UITapGestureRecognizer *)tapBgRecognizer
71 {
72     self.scrollView.contentOffset = CGPointZero;
73     [UIView animateWithDuration:0.5 animations:^{
74         self.lastImageView.frame = self.originalFrame;
75         tapBgRecognizer.view.backgroundColor = [UIColor clearColor];
76     } completion:^(BOOL finished) {
77         [tapBgRecognizer.view removeFromSuperview];
78         self.scrollView = nil;
79         self.lastImageView = nil;
80     }];
81 }
82 
83 //返回可缩放的视图
84 -(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
85 {
86     return self.lastImageView;
87 }