我使用github跟随谷歌的例子做了一个测试应用程序，但是做了一些更改（在firestore中使用的密钥更少，过滤器更少）。
问题是这样，当我在firestore中添加新密钥时，应用程序崩溃，但应用程序使用之前添加的两个密钥。
在fatalError("error")上崩溃并显示错误。我无法理解为什么有两个键应用程序工作，但如果我开始使用第三个键（大厅）然后应用程序崩溃。
可能是什么问题呢？
这是我的代码：
class ViewControllerTwo: UIViewController, UITableViewDelegate, UITableViewDataSource {
@IBOutlet var tableView: UITableView!
private var sweets: [Sweet] = []
private var document: [DocumentSnapshot] = []
fileprivate var query: Query? {
didSet {
if let listener = listener {
listener.remove()
}
}
}
private var listener: FIRListenerRegistration?
fileprivate func observeQuery() {
guard let query = query else { return }
stopObserving()
listener = query.addSnapshotListener { [unowned self] (snapshot, error) in
guard let snapshot = snapshot else {
print("Error fetching snapshot results: \(error!)")
return
}
let models = snapshot.documents.map { (document) -> Sweet in
if let model = Sweet(dictionary: document.data()) {
return model
} else {
fatalError("error")
}
}
self.sweets = models
self.document = snapshot.documents
self.tableView.reloadData()
}
}
@IBAction func filterButton(_ sender: Any) {
present(filters.navigationController, animated: true, completion: nil)
}
lazy private var filters: (navigationController: UINavigationController, filtersController: FilterViewController) = {
return FilterViewController.fromStoryboard(delegate: self)
}()
fileprivate func stopObserving() {
listener?.remove()
}
fileprivate func baseQuery() -> Query {
return Firestore.firestore().collection("sweets").limit(to: 50)
}
override func viewDidLoad() {
super.viewDidLoad()
query = baseQuery()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
observeQuery()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(true)
stopObserving()
}
deinit {
listener?.remove()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return sweets.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! ViewControllerCell
let sweet = sweets[indexPath.row]
cell.studioNameLabel.text = sweet.name
cell.studioAddressLabel.text = sweet.content
cell.hallNameLabel.text = sweet.hall
return cell
}
}
extension ViewControllerTwo: FiltersViewControllerDelegate {
func query(withCategory title: String?) -> Query {
var filtered = baseQuery()
if let title = title, !title.isEmpty {
filtered = filtered.whereField("title", isEqualTo: title)
}
return filtered
}
func controller(_ controller: FilterViewController, didSelectCategory title: String?) {
let filtered = query(withCategory: title)
self.query = filtered
observeQuery()
}
}
class ViewControllerCell: UITableViewCell {
@IBOutlet weak var studioNameLabel: UILabel!
@IBOutlet weak var studioAddressLabel: UILabel!
@IBOutlet weak var hallNameLabel: UILabel!
}
我的结构：
protocol DocumentSerializable {
init?(dictionary:[String:Any])
}
struct Sweet {
var name:String
var content:String
var hall:String
var dictionary:[String:Any] {
return [
"name": name,
"content" : content,
"hall" : hall
]
}
}
extension Sweet : DocumentSerializable {
static let title = [
"one",
"two",
"three",
"four"
]
init?(dictionary: [String : Any]) {
guard let name = dictionary["name"] as? String,
let content = dictionary["content"] as? String,
let hall = dictionary["hall"] as? String else { return nil }
self.init(name: name, content: content, hall: hall)
}
}
我的项目在谷歌驱动器
您只需在向现有结构添加任何新密钥后重新安装应用程序。
所以你应该在结构实现之前决定你需要什么键。或者，如果您将来添加新密钥，也可以重新安装应用程序。