Google Places API请求返回空数组，但打印所有响应 - 无错误

Question

我有以下无错代码，并且似乎无法使用任何用于我的结果数组的信息。玩过之后，我可以打印列出的每个businessID位置，但我无法添加/使用用于保存此信息的数组。我不明白为什么每个位置都打印出来，但我的数组显示为空。

我为我的代码全部道歉，但我花了几个小时试图纠正我的问题......

import UIKit 
import GooglePlaces 

class FoodTwo: UITableViewController { 

var placesClient: GMSPlacesClient! 

let international: [String] = ["ChIJAQDABX7CIogRIEY3k6r7R-g", 
"ChIJqX3q1IbCIogRFcuI05IPNDU", 
"ChIJAQDABX7CIogRY2MA6XVas8E"] 

let american: [String] = ["ChIJkX9tTSvoIogROXkxd0gpg3s", "ChIJy7lUZCfoIogRVBuB9jWKHUk", "ChIJyzCZMiroIogRkuMavnKsA0w", "ChIJbYvWJ5jCIogRxh0VQA_yD0I", "ChIJa4Sks23CIogRpRod4v5GEN8", "ChIJxVpGsNbpIogRG5HIAKbNyDU", "ChIJ1W32UyvoIogRyp_Rdxn6f8I", "ChIJwTht4ifoIogRsuXdEOrKGMk", "ChIJ6UXEgNPpIogR4Q3ZAAWQQSI", "ChIJUZVAjdTpIogRpyca26a6D8o",     "ChIJ6-h6_EctIIgRO1kypozaGGs", "ChIJK8NGam7CIogRlzU1TKeSjVI", "ChIJ7Xxh1m3CIogRZ_yabslUzd8", "ChIJ_dxSGJ7CIogRcYwJhjAm7TQ"] 

// more arrays here - deleted to reduce scrolling// 

var results = [GMSPlace]() 

var index: IndexPath! 

override func viewDidLoad() { 
    super.viewDidLoad() 

placesClient = GMSPlacesClient.shared() 
    var place: [String] 

    switch index.row 
    { 
    case 0 : 
     place = international 
    case 1 : 
     place = american 
    case 2 : 
     place = asian 
    case 3 : 
     place = bakery 
    case 4 : 
     place = bar 
    case 5 : 
     place = indian 
    case 6 : 
     place = italian 
    default : 
     place = mexican 
    } 
    for id in place 
    { 
     placesClient.lookUpPlaceID(id, callback: { (result, error) -> Void in 

      if let error = error { 
       print("lookup place id query error: \(error.localizedDescription)") 
       return 
      } 

      guard let result = result 
      else 
      { 
      print("No place details for \(id)") 
      return 
      } 
     self.results.append(result) 

     }) 
     OperationQueue.main.addOperation({() -> Void in 
      self.tableView.reloadData() 
       }) 

     } 
} 

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
    return results.count 
} 

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

    let each = results[indexPath.row] 
    cell.nameLabel.text = each.name 

    return cell 
} 
override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 

} 
} 

Answer 1

placesClient.lookUpPlaceID是异步函数。你必须等到它完成。所以，你实际上在之前重新加载了表格视图。

您应该在之后重新加载表格视图数组已填充。

for id in place { 
    placesClient.lookUpPlaceID(id) { result, error in 
     if let error = error { 
      print("lookup place id query error: \(error.localizedDescription)") 
      return 
     } 

     guard let result = result else { 
      print("No place details for \(id)") 
      return 
     } 

     self.results.append(result) 

     if place.count == self.results.count { 
      self.tableView.reloadData() 
     } 
    } 
}