Question

我对Firebase还是个新手，对Swift也很新，所以请原谅任何不正确的语法。我在读取Firebase中多个子节点下的数据时遇到一些麻烦，当在一个子节点下时显示数据，但是当我尝试将其定位在两个子节点下时，在基本上相同的条件下显示为nil。

adminClientHandle = ref.child("Test").child("client1").observe(.value, with : { (snapshot) in
            let adminClientStuff = snapshot.value as? [String:String]

            //Goals
            if adminClientStuff?["Goal 1"] != nil {
                self.adminGoal1.text = adminClientStuff?["Goal 1"]
            } else {
                self.adminGoal1.text = "nil"
            }

ref = Database.database().reference() on viewDidLoad

firebase数据库如下所示：

{
  "Test" : {
    "client1" : {
      "Goal 1" : "Goal 1",
      "Goal 1 %" : "100",
      "Goal 1 Correct" : 1,
      "Goal 1 Total" : "1",
      "Goal 2" : "Will keep personal space for 10 minutes",
      "Goal 2 %" : "0",
      "Goal 2 Correct" : 1,
      "Goal 2 Total" : "1",
      "Goal 3" : "Will recall events that happened in the last hour",
      "Goal 3 %" : "0",
      "Goal 3 Correct" : 1,
      "Goal 3 Total" : "1"
    }
  }
}

adminClientStuff?["Goal 1"]返回nil，即使在子节点上使用类似的代码返回实际的字符串也是如此。请让我知道是否有任何可能会丢失的东西，但是我尝试了很多，却没有获得理想的结果。

Answer 1

看看您的结构，其中包含各种值

  "Goal 1" : "Goal 1",
  "Goal 1 %" : "100",
  "Goal 1 Correct" : 1,

所以这是行不通的，因为这是一个异构的集合文字问题

let adminClientStuff = snapshot.value as? [String:String]

需要这样定义

let adminClientStuff = snapshot.value as? [String:Any]

我还建议使用另一种解决方案，以保护您的代码，以防丢失或丢失预期的值。

let goal1 = snapshot.childSnapshot(forPath: "Goal 1").value as? String ?? "No Goal value"
let goal1Percent = snapshot.childSnapshot(forPath: "Goal 1 %").value as? String ?? "No Goal value"
let goal1Correct = snapshot.childSnapshot(forPath: "Goal 1 Correct").value as? Int ?? 0
print(goal1, goal1Percent, goal1Correct)

无法读取多个子节点（Firebase）

1 个答案: