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iOS点击图片查看大图,自由缩放功能的实现

iOS点击图片查看大图,自由缩放功能的实现

作者: 忆一曲肝肠断 | 来源:发表于2020-04-22 15:24 被阅读0次

    在我们开发项目中,经常会遇到点击图片查看图片大图,而且可以自由缩放的功能,今天就讲一讲它的实现方法

    - (void)viewDidLoad {

        [super viewDidLoad];

        [selfsetUp];

        [selfloadData];

        // Do any additional setup after loading the view.

    }

    -(void)setUp{

    _scrollView = [[UIScrollView alloc] init];

        [_scrollView setTranslatesAutoresizingMaskIntoConstraints:NO];

        _scrollView.backgroundColor = [UIColor blackColor];

        _scrollView.maximumZoomScale = 5;

        _scrollView.delegate = self;

        [self.view addSubview:_scrollView];

        [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[scrollView]-0-|" options:kNilOptions metrics:nil views:@{@"scrollView":_scrollView}]];

        [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[scrollView]-0-|" options:kNilOptions metrics:nil views:@{@"scrollView":_scrollView}]];

        _imageView= [[UIImageViewalloc]init];

        [_imageView setTranslatesAutoresizingMaskIntoConstraints:NO];

        _imageView.contentMode = UIViewContentModeScaleAspectFit;//缩放显示

        _imageView.userInteractionEnabled = YES;

        [_scrollView addSubview:_imageView];

        [_scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[imageView(scrollView)]-0-|" options:kNilOptions metrics:nil views:@{@"imageView":_imageView,@"scrollView":_scrollView}]];

        [_scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[imageView(scrollView)]-0-|" options:kNilOptions metrics:nil views:@{@"imageView":_imageView,@"scrollView":_scrollView}]];

        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismiss)];

        [_imageView addGestureRecognizer:tap];

    -(void)loadData{

        if(_image){

            _imageView.image = _image;

        }

        if(_imageUrl.length>0){

            [_imageView setImageWithURL:[NSURL URLWithString:_imageUrl]];

        }

    }

    -(void)dismiss{

        [self dismissViewControllerAnimated:YES completion:nil];

    }

    #pragma mark - UIScrollViewDelegate

    - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{

        return _imageView;

    }

    是不是一目了然。简单粗暴,每天更新一个iOS小功能,喜欢的记得点赞加关注哦

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