ios - 仅当捏住单元格的 imageView 时，才可以在 UICollectionView 的自定义单元格中放大/缩小 UIImageView？

Question

我有一个包含一个自定义单元格的 CollectionView。

我想在单元格中放大/缩小 imageView，所以我在 CollectionView.m 中添加了捏合手势

当我向 self.collectionView 添加手势时，如下所示:

[self.collectionView addGestureRecognizer:pinchGesture];

有效!我的 cell.imageView 可以放大/缩小，但是当我捏其他地方时(不是在单元格的 imageView 中，我的 cell.imageView 仍然用手势放大/缩小，我希望 cell.imageView 放大/缩小时用户捏cell.imageView，所以我尝试使用此代码添加手势:

[cell.imageView addGestureRecognizer:pinchGesture];

但不幸的是它不起作用。当我捏住单元格的 imageView 时没有任何反应。

所以我的问题是，是否可以仅在用户捏住单元格的 ImageView 时放大/缩小单元格的 ImageView ？不是其他地方。

Answer 1

Collection View 单元格

//cell.h

#import <UIKit/UIKit.h>

@interface Cell : UICollectionViewCell

@property (weak, nonatomic) IBOutlet UIScrollView *scrollview;
@property (weak, nonatomic) IBOutlet UIImageView *imageview;

- (void)setup;

@end


//cell.m

#import "Cell.h"
#define MAXIMUM_SCALE 3.0
#define MINIMUM_SCALE    1.0

@interface Cell()<UIScrollViewDelegate>

@end

@implementation Cell

- (void)setup {

    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(zoomImage:)];
    self.imageview.gestureRecognizers = @[pinch];
    self.imageview.userInteractionEnabled = YES;
    self.scrollview.delegate = self;

}

//-----------------------------------------------------------------------

#pragma  mark  - Scrollview Delegate Method

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return self.imageview;
}

//-----------------------------------------------------------------------

#pragma mark - Custom Methods

- (void)zoomImage:(UIPinchGestureRecognizer *)gesture {
    if (gesture.state == UIGestureRecognizerStateEnded
    || gesture.state == UIGestureRecognizerStateChanged) {
        NSLog(@"gesture.scale = %f", gesture.scale);

        CGFloat currentScale = self.frame.size.width / self.bounds.size.width;
        CGFloat newScale = currentScale * gesture.scale;

        if (newScale < MINIMUM_SCALE) {
            newScale = MINIMUM_SCALE;
        }
        if (newScale > MAXIMUM_SCALE) {
            newScale = MAXIMUM_SCALE;
        }

        CGAffineTransform transform = CGAffineTransformMakeScale(newScale, newScale);
        self.imageview.transform = transform;
        self.scrollview.contentSize = self.imageview.frame.size;

    }

}

@end

View Controller 文件

//ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController


@end



//ViewController.m[![enter image description here][1]][1]


#import "ViewController.h"
#import "Cell.h"

@interface ViewController ()<UICollectionViewDataSource, UICollectionViewDelegate>

@property (weak, nonatomic) IBOutlet UICollectionView *collectionView;
@property (strong, nonatomic) NSArray  *imageArray;

@end

@implementation ViewController

//-----------------------------------------------------------------------

#pragma mark - Collectionview Datasource Methods

//-----------------------------------------------------------------------

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return self.imageArray.count;
}

//-----------------------------------------------------------------------

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {

    Cell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    [cell setup];
    cell.imageview.image = [UIImage imageNamed:[self.imageArray objectAtIndex:indexPath.row]];
    return cell;
}

//-----------------------------------------------------------------------

#pragma mark - Lifecycle method

- (void)viewDidLoad {
    [super viewDidLoad];

    _imageArray = @[ @"1.jpg", @"1.jpg" ];
    self.collectionView.dataSource = self;
    self.collectionView.delegate = self;

}

//-----------------------------------------------------------------------

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

注意:您需要为 Storyboard中的 ScrollView 、 ImageView 和 Collection View 创建一个 IBOutlet。