swift從一個完成塊獲得最終數組

Question

我有一個完成塊，從Firebase返回一個Assync數組，我遇到的問題是單個數組打印每個數組，因爲它檢索它們我只想檢索最終數組當它完成時。我怎樣才能做到這一點？

這是正在打印

[["lat": 37.33150355, "long": -122.03071596]] 
[["lat": 37.33150355, "long": -122.03071596], ["lat": 37.32550194, "long": -122.01974475]] 
[["lat": 37.33150355, "long": -122.03071596], ["lat": 37.32550194, "long": -122.01974475], ["lat": 37.332431, "long": -122.030713]] 

---

func dashMapView() { 
    locationManager.delegate = self 
    mapView.delegate = self 
    locationManager.requestAlwaysAuthorization() 
    mapView.addObserver(self, forKeyPath: "myLocation", options: NSKeyValueObservingOptions.New, context: nil) 
    var helprInfo = [[String: AnyObject]]() 
    currentIhelprInfo { (result) in 
     //helprInfo = result 
     helprInfo.append(result) 
     print(helprInfo) 
    } 
} 
// get curren Ihelper info 
func currentIhelprInfo(completion: (result: [String: AnyObject]) ->()) { 
    var userAllInfo: [[String: AnyObject]]! 
    let dbref = FIRDatabase.database().reference() 
    dbref.child("users").queryOrderedByChild("receivePostRequest/status").queryEqualToValue(true).observeEventType(.Value, withBlock: { snapshot in 
     for child in snapshot.children { 
      let request = child.childSnapshotForPath("receivePostRequest") 
      var lat = request.value!["lat"] as! Double 
      var long = request.value!["long"] as! Double 
      var userInfo = [ 
       "lat": lat, 
       "long": long 
      ] 
      //var userArray = userAllInfo.append(userInfo) 
      completion(result: userInfo) 
     } 
    }) 
} 

Answer 1

要調用內部的完成處理程序循環的結果。確保迭代數據，首先完成邏輯並僅在準備好userInfo陣列時完成。

您的.observeEventType(.Value,回調將如下所示：

var helprInfo = [[String: AnyObject]]() 
for child in snapshot.children { 
    let request = child.childSnapshotForPath("receivePostRequest") 
    var lat = request.value!["lat"] as! Double 
    var long = request.value!["long"] as! Double 
    var userInfo = [ 
     "lat": lat, 
     "long": long 
    ] 
    helprInfo.append(userInfo) 
} 
completion(result: helprInfo) 

而且你完成處理程序將只打印在完成處理程序通過了陣列。

currentIhelprInfo { (result) in 
    print(result) 
}