iOS开发 UI高级图片放大缩小的实现

最新推荐文章于 2020-12-30 06:48:36 发布

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最新推荐文章于 2020-12-30 06:48:36 发布

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分类专栏：图片文章标签： ios开发图片 ui

本文链接：https://blog.youkuaiyun.com/A_Studystudy/article/details/52347640

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本文介绍如何在iOS应用中实现在UI上对图片进行放大和缩小操作。通过创建自定义的ChangeScaleView，利用UIImageView和UIScrollView，结合手势识别，实现了平滑的图片缩放效果。在tapAction方法中，图片被放大并填充到ScrollView，背景色变为橙色；在smallTapGesture方法中，图片会恢复到原始大小。

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#import <UIKit/UIKit.h>

@interface ChangeScaleView : UIImageView
@property(nonatomic,strong)UIScrollView *scrollView;
@property(nonatomic,strong)UIImageView *scaleImageView;
@end

#import "ChangeScaleView.h"

@implementation ChangeScaleView

-(instancetype)initWithFrame:(CGRect)frame{
    if ([super initWithFrame:frame]) {
        [self createTap];
    }
    return self;
}

-(void)createTap{
    
    self.userInteractionEnabled = YES;
    // 初始化手势
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapAction:)];
    [self addGestureRecognizer:tapGesture];
}

#pragma mark - 放大手势的响应事件
-(void)tapAction:(UITapGestureRecognizer *)tap{
    
    [self createView];
    
    [UIView animateWithDuration:.5 animations:^{
        _scaleImageView.frame = _scrollView.frame;
        _scrollView.backgroundColor = [UIColor orangeColor];
        self.hidden = YES;
    }];
}

-(void)createView{
    //初始化滑动视图
    _scrollView = [[UIScrollView alloc] initWithFrame:[UIScreen mainScreen].bounds];
    _scrollView.showsHorizontalScrollIndicator = NO;
    _scrollView.showsVerticalScrollIndicator = NO;
    [self.window addSubview:_scrollView];
    // 移到原来所在位置
    CGRect frame = [self convertRect:self.bounds toView:self.window];
    _scaleImageView = [[UIImageView alloc] initWithFrame:frame];
    
    _scaleImageView.image = self.image;
    
    _scaleImageView.userInteractionEnabled = YES;
    //添加手势
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(smallTapGesture:)];
    [_scaleImageView addGestureRecognizer:tap];
    [_scrollView addSubview:_scaleImageView];

}

//缩小手势的响应事件
-(void)smallTapGesture:(UITapGestureRecognizer *)tap{
    
    [UIView animateWithDuration:.3 animations:^{
        
        _scaleImageView.frame = self.frame;
        
    } completion:^(BOOL finished) {
        self.hidden = NO;
        [_scrollView removeFromSuperview];
        
    }];
}