以下代码表达了我的问题：（它是自包含的，您可以使用空模板创建一个 Xcode 项目，替换 main.m 文件的内容，删除 AppDelegate.h/.m 文件并构建它）
//
// main.m
// CollectionViewProblem
//
#import <UIKit/UIKit.h>
@interface Cell : UICollectionViewCell
@property (nonatomic, strong) UIButton *button;
@property (nonatomic, strong) UILabel *label;
@end
@implementation Cell
- (id)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame])
{
self.label = [[UILabel alloc] initWithFrame:self.bounds];
self.label.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
self.label.backgroundColor = [UIColor greenColor];
self.label.textAlignment = NSTextAlignmentCenter;
self.button = [UIButton buttonWithType:UIButtonTypeInfoLight];
self.button.frame = CGRectMake(-frame.size.width/4, -frame.size.width/4, frame.size.width/2, frame.size.width/2);
self.button.backgroundColor = [UIColor redColor];
[self.button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.contentView addSubview:self.label];
[self.contentView addSubview:self.button];
}
return self;
}
// Overriding this because the button's rect is partially outside the parent-view's bounds:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
if ([super pointInside:point withEvent:event])
{
NSLog(@"inside cell");
return YES;
}
if ([self.button
pointInside:[self convertPoint:point
toView:self.button] withEvent:nil])
{
NSLog(@"inside button");
return YES;
}
return NO;
}
- (void)buttonClicked:(UIButton *)sender
{
NSLog(@"button clicked!");
}
@end
@interface ViewController : UICollectionViewController
@end
@implementation ViewController
// (1a) viewdidLoad:
- (void)viewDidLoad
{
[super viewDidLoad];
[self.collectionView registerClass:[Cell class] forCellWithReuseIdentifier:@"ID"];
}
// collection view data source methods ////////////////////////////////////
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 100;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
Cell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"ID" forIndexPath:indexPath];
cell.label.text = [NSString stringWithFormat:@"%d", indexPath.row];
return cell;
}
///////////////////////////////////////////////////////////////////////////
// collection view delegate methods ////////////////////////////////////////
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"cell #%d was selected", indexPath.row);
}
////////////////////////////////////////////////////////////////////////////
@end
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
ViewController *vc = [[ViewController alloc] initWithCollectionViewLayout:layout];
layout.itemSize = CGSizeMake(128, 128);
layout.minimumInteritemSpacing = 64;
layout.minimumLineSpacing = 64;
layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
layout.sectionInset = UIEdgeInsetsMake(32, 32, 32, 32);
self.window.rootViewController = vc;
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
@end
int main(int argc, char *argv[])
{
@autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
基本上我正在使用集合视图创建一个 Springboard 类型的 UI。我的UICollectionViewCell子类（Cell）有一个按钮，该按钮部分位于单元格的contentView（即其超级视图）边界之外。
问题是单击contentView边界之外的按钮的任何部分（基本上是按钮的 3/4）不会调用按钮操作。只有单击与contentView重叠的按钮部分时，才会调用按钮的操作方法。
我什至重写了Cell-pointInside:withEvent:中的方法，以便确认按钮中的触摸。但这对按钮点击问题没有帮助。
我猜这可能与collectionView如何处理触摸有关，但我不知道是什么。我知道UICollectionView是一个UIScrollView子类，我实际上已经测试过覆盖-pointInside:withEvent:包含部分重叠按钮的视图（将子视图制作为滚动视图）可以解决按钮单击问题，但它在这里不起作用。
有什么帮助吗？
** 补充：作为记录，我目前对该问题的解决方案包括在contentView中插入一个较小的子视图，从而使单元格具有其外观。删除按钮被添加到contentView中，使其矩形实际上位于 contentView 的范围内，但仅部分重叠单元格的可见部分（即插入子视图）。所以我得到了我想要的效果，并且按钮工作正常。但是我仍然对上面原始实现的问题感到好奇。