提示：UICollectionView must be initialized with a non-nil layout parameter
1.检查 UICollectionViewDelegateFlowLayout(注意此处不是UICollectionViewFlowLayout)和下面的方法是否成功添加。
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 100, height: 200)
}
UICollectionViewDelegateFlowLayout相关的几个方法
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
}
2.检查colletionView初始化方式
//2.1初始化
collectionView = UICollectionView.init(frame: CGRect(x: 0, y: 0, width: kWidth_swift, height: kHeight_Swift), collectionViewLayout: layout!)
//2.2初始化
self.collectionView = UICollectionView.init(frame: CGRect(x: 0, y: 0, width: kWidth_swift, height: kHeight_Swift), collectionViewLayout: layout!)
//后记：当天重启电脑没用，第二天重启电脑用2.1初始化方式又好了，mmp...
3.UICollectionReusableView注册失败，原因是ReuseIdentifier错误，没有和注册时保持一致
collectionView.register(UICollectionReusableView.self, forSupplementaryViewOfKind: "UICollectionElementKindSectionHeader", withReuseIdentifier: "SectionHeader")
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
var reusableView: UICollectionReusableView!
if kind == UICollectionView.elementKindSectionHeader {
reusableView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "SectionHeader", for: indexPath)
let sectionHeader = UIButton(frame: CGRect(x: 120, y: 16, width: kWidth_swift, height: 32))
reusableView.addSubview(sectionHeader)
return reusableView;
}else{
return UICollectionReusableView();
}
}
'NSInternalInconsistencyException', reason: 'could not dequeue a view of kind: UICollectionElementKindSectionHeader with identifier Header - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
