在TableView Cell中显示来自Firebase的数据

Question

我的VC中有一个代码（作为我的大型项目的一部分）中有以下代码。我的一个Firebase数据库引用被称为Sell_Request。它有三个孩子（name,latitude和longitude），但我现在只关注name。

我想将它添加到一个字符串数组，并将其打印到控制台。我看到正在打印到控制台的名称，但我没有得到单个单元格中打印的名称。

感谢您的期待。

import UIKit 
import Firebase 
import FirebaseDatabase 
import MapKit 
import CoreLocation 

class RequestVC: UITableViewController, CLLocationManagerDelegate { 

    var locationManager = CLLocationManager() 
    var sellerUserNames = [String]() 

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
     if segue.identifier == "backToMain" { 
      self.navigationController?.navigationBar.isHidden = true 
     } 
    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     locationManager.delegate = self 
     locationManager.desiredAccuracy = kCLLocationAccuracyBest 
     locationManager.requestWhenInUseAuthorization() 
     locationManager.startUpdatingLocation() 

    } 

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
     if let location = manager.location?.coordinate { 
      let databaseRef = FIRDatabase.database().reference() 
      databaseRef.child("Sell_Request").queryOrderedByKey().observe(.childAdded, with: { (FIRDataSnapshot) in 

       if let data = FIRDataSnapshot.value as? NSDictionary { 
        if let name = data[Constants.NAME] as? String { 
           self.sellerUserNames.append(name) 
           print(name) 
           } 
          } 
         }) 
        } 
       } 


    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 



    // MARK: - Table view data source 

    override func numberOfSections(in 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 sellerUserNames.count 
    } 


    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 
     let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) 

     cell.textLabel?.text = sellerUserNames[indexPath.row] 

     return cell 
    } 


    /* 
    // Override to support conditional editing of the table view. 
    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool { 
     // Return false if you do not want the specified item to be editable. 
     return true 
    } 
    */ 

    /* 
    // Override to support editing the table view. 
    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) { 
     if editingStyle == .delete { 
      // Delete the row from the data source 
      tableView.deleteRows(at: [indexPath], with: .fade) 
     } else if editingStyle == .insert { 
      // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view 
     }  
    } 
    */ 

    /* 
    // Override to support rearranging the table view. 
    override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) { 

    } 
    */ 

    /* 
    // Override to support conditional rearranging of the table view. 
    override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool { 
     // Return false if you do not want the item to be re-orderable. 
     return true 
    } 
    */ 

    /* 
    // MARK: - Navigation 

    // In a storyboard-based application, you will often want to do a little preparation before navigation 
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
     // Get the new view controller using segue.destinationViewController. 
     // Pass the selected object to the new view controller. 
    } 
    */ 

} 

Answer 1

你只需要调用tableView.reloadData()你追加的名字到sellerUserNames阵列后，改变你的功能，这...

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    if let location = manager.location?.coordinate { 
     let databaseRef = FIRDatabase.database().reference() 

     sellerUserNames.removeAll() 
     databaseRef.child("Sell_Request").queryOrderedByKey().observe(.childAdded, with: { (FIRDataSnapshot) in 

      if let data = FIRDataSnapshot.value as? NSDictionary { 
       if let name = data[Constants.NAME] as? String { 
          self.sellerUserNames.append(name) 
          print(name) 
          self.tableView.reloadData() 
          } 
         } 
        }) 
       } 
      } 

编辑

其中/时你想打电话sellerUserNames.removeAll()取决于你的代码和你的表视图的生命周期，但我已经编辑了我的代码上面添加它在哪里它是最li乖巧。

Answer 2

TableView需要数据源后，重载发生在你的代码即sellerUserNames。所以在将名称追加到sellerUserNames之后，您需要重新加载tableview。

在追加名称后添加下面这行代码。

self.tableView.reloadData()