基本上，我在UICollectionView中有一个UIView（用于扩展集合视图数据和委托协议）。某些UICollectionView函数，例如numberofSections和numberOfItemsInSection被调用，而其他函数，例如cellForRowAt，则没有被调用。
有问题的集合视图为rolesCollectionView，其数据为roles数组。我添加了一些打印语句，以查看正在调用的函数，而只有上述函数被调用。我还可以肯定RolesCollectionViewCell并不是问题，如有必要，我也可以提供其代码。
class ProjectSearchViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
var rolesCollectionView: UICollectionView!
var roles = ["Developer", "Designer", "Backend Developer", "Frontend Developer"]
override func viewDidLoad() {
super.viewDidLoad()
print("test")
// Do any additional setup after loading the view.
navigationItem.title = "Search Projects"
view.backgroundColor = .white
var rolesLayout = UICollectionViewFlowLayout()
rolesLayout.scrollDirection = .horizontal
rolesLayout.minimumLineSpacing = 8
rolesLayout.minimumInteritemSpacing = 8
rolesLayout.sectionInset = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
rolesLayout.estimatedItemSize = CGSize(width: 50, height: 25)
rolesCollectionView = UICollectionView(frame: .zero, collectionViewLayout: rolesLayout)
rolesCollectionView.backgroundColor = .white
rolesCollectionView.delegate = self
rolesCollectionView.dataSource = self
rolesCollectionView.register(RolesCollectionViewCell.self, forCellWithReuseIdentifier: "role")
rolesCollectionView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(rolesCollectionView)
rolesCollectionView.reloadData()
let newView = UIView()
newView.backgroundColor = .black
newView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(newView)
NSLayoutConstraint.activate([
newView.widthAnchor.constraint(equalToConstant: 50),
newView.heightAnchor.constraint(equalToConstant: 50),
newView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
newView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
])
setupConstraints()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// if collectionView == self.rolesCollectionView {
print("return")
print(roles.count)
return roles.count
// } else {
// return 0
// }
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
print("section")
return 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
print("cell for item at")
if collectionView == self.rolesCollectionView {
var cell = rolesCollectionView.dequeueReusableCell(withReuseIdentifier: "role", for: indexPath) as! RolesCollectionViewCell
cell.configure(roleName: roles[indexPath.row])
print(roles[indexPath.row])
return cell
} else {
return UICollectionViewCell()
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
//if collectionView == self.rolesCollectionView {
print("size")
print("test: \(collectionView == rolesCollectionView)")
return CGSize(width: 15.0, height: 15.0)
// }
}
func setupConstraints() {
NSLayoutConstraint.activate([
rolesCollectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 8),
rolesCollectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -8),
rolesCollectionView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 8)
//rolesCollectionView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bot)
])
}
}