我有两个表视图。一种是用户单击的，另一种是显示数据的。当用户单击第一个表视图中的单元格时，将对我的 firebase 数据库进行查询，并将查询存储在数组中。然后我通过 segue 传递数据。我使用了属性观察器，因此我知道正在设置变量。通过使用断点，我能够确定我的变量在 cellForRowAtIndexPath 方法之前获取其值。我需要帮助在表视图中显示数据。我不知道在哪里重新加载数据以使表视图更新我的数据。我正在使用斯威夫特。
编辑2：我已经解决了我的问题。我将发布我的第一个和第二个表视图，以便您可以看到我的解决方案。
第一个表视图
import UIKit
import Firebase
import FirebaseDatabase
class GenreTableViewController: UITableViewController {
let dataBase = FIRDatabase.database()
var genreArray = ["Drama","Classic,Comic/Graphic novel","Crime/Detective","Fable,Fairy tale","Fantasy","Fiction narrative", "Fiction in verse","Folklore","Historical fiction","Horror","Humour","Legend","Magical realism","Metafiction","Mystery","Mythology","Mythopoeia","Realistic fiction","Science fiction","Short story","Suspense/Thriller","Tall tale","Western,Biography","Autobiography","Essay","Narrative nonfiction/Personal narrative","Memoir","Speech","Textbook","Reference book","Self-help book","Journalism", "Religon"]
var ResultArray: [NSObject] = []
var infoArray:[AnyObject] = []
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return genreArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
// Configure the cell...
cell.textLabel?.text = genreArray[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let DestViewController: ResultTableViewController = segue.destinationViewController as! ResultTableViewController
if segue.identifier == "letsGo" {
if let indexPath = self.tableView.indexPathForSelectedRow {
let tappedItem = self.genreArray[indexPath.row]
DestViewController.someString = tappedItem
}
}
}
}
import UIKit
import Firebase
import FirebaseDatabase
class ResultTableViewController: UITableViewController {
let dataBase = FIRDatabase.database()
var SecondResultArray: [FIRDataSnapshot]! = []
var someString: String?{
didSet {
print("I AM A LARGE TEXT")
print(someString)
}
}
override func viewDidLoad() {
let bookRef = dataBase.reference().child("books")
bookRef.queryOrderedByChild("Genre")
.queryEqualToValue(someString)
.observeSingleEventOfType(.Value, withBlock:{ snapshot in
for child in snapshot.children {
self.SecondResultArray.append(child as! FIRDataSnapshot)
//print(self.ResultArray)
}
dispatch_async(dispatch_get_main_queue()) {
self.tableView.reloadData()
}
})
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return SecondResultArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell2", forIndexPath: indexPath)
// Configure the cell...
let bookSnapShot: FIRDataSnapshot! = self.SecondResultArray[indexPath.row]
let book = bookSnapShot.value as! Dictionary<String, String>
let Author = book["Author"] as String!
let Comment = book["Comment"] as String!
let Genre = book["Genre"] as String!
let User = book["User"] as String!
let title = book["title"] as String!
cell.textLabel?.numberOfLines = 0
cell.textLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping
cell.textLabel?.text = "Author: " + Author + "\n" + "Comment: " + Comment + "\n" + "Genre: " + Genre + "\n" + "User: " + User + "\n" + "Title: " + title
let photoUrl = book["bookPhoto"], url = NSURL(string:photoUrl!), data = NSData(contentsOfURL: url!)
cell.imageView?.image = UIImage(data: data!)
return cell
}
}
为了更好的上下文和故障排除，这里是我当前应该显示数据的 tableView 代码：
import UIKit
class ResultTableViewController: UITableViewController {
var SecondResultArray: Array<NSObject> = []{
willSet(newVal){
print("The old value was \(SecondResultArray) and the new value is \(newVal)")
}
didSet(oldVal){
print("The old value was \(oldVal) and the new value is \(SecondResultArray)")
self.tableView.reloadData()
}
}
override func viewDidLoad() {
print ("I have this many elements\(SecondResultArray.count)")
super.viewDidLoad()
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return SecondResultArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell2", forIndexPath: indexPath)
cell.textLabel?.text = SecondResultArray[indexPath.row] as? String
return cell
}
}
Edit:
这是我的第一个表视图控制器。我尝试过使用完成处理程序，但无法正确调用它，而且我的查询发生在 didSelectRowAtIndexPath 方法中这一事实使我感到受限。请帮忙。
import UIKit
import Firebase
import FirebaseDatabase
class GenreTableViewController: UITableViewController {
let dataBase = FIRDatabase.database()
var genreArray = ["Drama","Classic,Comic/Graphic novel","Crime/Detective","Fable,Fairy tale","Fantasy","Fiction narrative", "Fiction in verse","Folklore","Historical fiction","Horror","Humour","Legend","Magical realism","Metafiction","Mystery","Mythology","Mythopoeia","Realistic fiction","Science fiction","Short story","Suspense/Thriller","Tall tale","Western,Biography","Autobiography","Essay","Narrative nonfiction/Personal narrative","Memoir","Speech","Textbook","Reference book","Self-help book","Journalism", "Religon"]
var ResultArray: [NSObject] = []
var infoArray:[AnyObject] = []
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return genreArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
cell.textLabel?.text = genreArray[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
typealias CompletionHandler = (result:NSObject?, error: NSError?) -> Void
func getData(completionHandeler: CompletionHandler){
let bookRef = self.dataBase.reference().child("books")
let GenreSelector = self.genreArray[indexPath.row]
bookRef.queryOrderedByChild("Genre")
.queryEqualToValue(GenreSelector)
.observeSingleEventOfType(.Value, withBlock:{ snapshot in
for child in snapshot.children {
print("Loading group \((child.key!))")
self.ResultArray.append(child as! NSObject)
}
print(self.ResultArray)
self.performSegueWithIdentifier("letsGo", sender: self)
self.tableView.reloadData()
})
}
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var DestViewController: ResultTableViewController = segue.destinationViewController as! ResultTableViewController
DestViewController.SecondResultArray = self.ResultArray
}
