我正在尝试从子类别中获取信息,我设法使用此代码检索了类别中的子类别。
但是,在调用子类别中的数据时遇到了一些麻烦。
//让我们下载食谱列表及其详细信息
self.ref.child("Categories").observe(.childAdded) { (snapshot) in
self.subcategories.removeAll()
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? DataSnapshot {
self.subcategories.append(rest.key)
}
self.subcollectionView.reloadData()
}
}
我以前曾发布过此邮件,但帐户有问题。
这是我用来获取子类别信息的代码。
非常感谢我应该做的一个例子,因为我是快速编码的新手
@IBOutlet weak var card_cv: UICollectionView!
reference for the database
var refCategories: DatabaseReference!
var subcategories = [String]()
// declare a string to receive the category name
var subCategoryName:String!
override func viewDidLoad() {
super.viewDidLoad()
// declare the reference to database
refCategories = Database.database().reference()
// setting the subcategory name as view controller's table
self.title = subCategoryName
// let's set delegate for the tableview
self.card_cv.dataSource = self
self.card_cv.delegate = self
// function to download list from database
self.downloadSubCategoriesFromDatabase()
}
Custom function download
func downloadSubCategoriesFromDatabase(){
self.subcategories.removeAll()
// download the snapshot
self.refCategories.child("Categories").child(subCategoryName).observeSingleEvent(of: .value) { (snapshot) in
self.subcategories.removeAll()
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? DataSnapshot {
self.subcategories.append(rest.key)
}
self.card_cv.reloadData()
}
}