编程UICollectionViewCell
编程UICollectionViewCell
提问于 2016-02-08 07:07:15
我试图在不使用故事板的情况下以编程方式创建一个单元格，但我遇到了一些问题。单元格代码如下。
import UIKit
class ProductCategoryCollectionViewCell: UICollectionViewCell {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.setupCell()
}
var productCategoryImageView :UIImageView!
func setupCell(){
//seting up the imageView as subView
productCategoryImageView = UIImageView()
productCategoryImageView.translatesAutoresizingMaskIntoConstraints = false
let subViewDictionary = ["productCategoryImageViewKey" : productCategoryImageView]
let productCategoryImageViewWidth = contentView.bounds.size.width
let productCategoryImageViewHeight = contentView.bounds.size.height
let productCategoryImageViewHorizontalConstrain = NSLayoutConstraint.constraintsWithVisualFormat("H:[productCategoryImageViewKey(\(productCategoryImageViewWidth))]", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: subViewDictionary)
let productCategoryImageViewVerticalConstrain = NSLayoutConstraint.constraintsWithVisualFormat("V:[productCategoryImageViewKey(\(productCategoryImageViewHeight))]", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: subViewDictionary)
productCategoryImageView.addConstraints(productCategoryImageViewHorizontalConstrain)
productCategoryImageView.addConstraints(productCategoryImageViewVerticalConstrain)
contentView.addSubview(productCategoryImageView)
contentView.backgroundColor = UIColor(red: 1, green: 0, blue: 0, alpha: 0.4)
}}
我正在尝试创建一个subImageView，它将是单元格的大小，但是它不会缩放到单元格的大小。
回答 2
Stack Overflow用户
回答已采纳
发布于 2016-02-08 07:31:41
调用init方法时不知道单元格的大小。因此，将宽度和高度设置为contentView.bounds.size.width和contentView.bounds.size.height将无法工作。
不必为水平和垂直大小添加约束，您可以添加左、右、顶和底约束，如下所示：
let productCategoryImageViewHorizontalConstrain = NSLayoutConstraint.constraintsWithVisualFormat("H:|-0-[productCategoryImageViewKey]-0-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: subViewDictionary)
let productCategoryImageViewVerticalConstrain = NSLayoutConstraint.constraintsWithVisualFormat("V:|-0-[productCategoryImageViewKey]-0-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: subViewDictionary)在添加约束之前，还应该调用contentView.addSubview(productCategoryImageView)。
Stack Overflow用户
发布于 2016-02-08 07:23:30
/*以编程方式创建一个UICollectionView单元，如上面的代码*/
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
uicollection=[[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:layout];
[uicollection setDataSource:self];
[uicollection setDelegate:self];
[uicollection registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentifier"];
[uicollection setBackgroundColor:[UIColor redColor]];
[self.view addSubview:uicollection];
// Do any additional setup after loading the view, typically from a nib.
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 15;
}
// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath];
cell.backgroundColor=[UIColor greenColor];
return cell;
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(50, 50);
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/35264049
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