如何在ios应用程序中检索firebase数据库中的数据？我的JSON数据如下所示，我希望得到与questiontext关联的每个值，A…E

JSON数据如下：

{
    "Questions": {
        "1": {
            "questiontext": "Which choice best describes what happens in the\npassage?",
            "A": "One character argues with another character who intrudes on her home.",
            "B": "One character receives a surprising request from\nanother character",
            "C": "One character reminisces about choices she has\nmade over the years.",
            "D": "One character criticizes another character for\npursuing an unexpected course of action.",
            "E": "null"
        },
        "2": {
            "questiontext": "Which choice best describes the developmental pattern of the passage?",
            "A": "A careful analysis of a traditional practice",
            "B": "A detailed depiction of a meaningful encounter",
            "C": "A definitive response to a series of questions",
            "D": "A cheerful recounting of an ammusing anecdote",
            "E": "null"
        }
    }
}

---

您可能会发现您的结构存在一些挑战，因此将来可能需要进行更改

由于您的问题非常具体，关于包含的结构，下面介绍如何访问问题1的值，回答A（或B、C、D等）

输出是

One character argues with another character who intrudes on her home.

现在，如果您想获得所有子节点A-E，那么下面是代码

let q1Ref = self.ref.child("Questions").child("1")
q1Ref.observeSingleEvent(of: .value, with: { snapshot in
    for child in snapshot.children {
        let snap = child as! DataSnapshot
        let key = snap.key
        let value = snap.value as! String
        print("Answer \(key) is \(value)")
    }
})

输出将是

Answer A is One character argues with another character who intrudes on her home.
Answer B is One character receives a surprising request from\nanother character
Answer C is One character reminisces about choices she has\nmade over the years.
Answer D is One character criticizes another character for\npursuing an unexpected course of action.
Answer E is null

发表评论；这假设您的Firebase根引用定义如下：

class ViewController: UIViewController {
    var ref: DatabaseReference!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.ref = Database.database().reference()

您的firebase结构键是1、2、3（如在数组中*），而不是“1”、“2”、“3”

您可以通过查看Firebase控制台并查看键是否用引号括起来来区分它们之间的差异；1不同于“1”

最好使用.childByAutoId来创建父节点键，而不是数字（数组）

---

*应避免在Firebase中使用阵列。请参见

谢谢您的回答，但我需要直接从Firebase访问此答案。此答案的作用是什么？i、 e.它将如何从firebase加载指定的节点，并使OP能够访问与A、B、C等节点相关的谨慎答案？我尝试了上述代码，但不起作用。我尝试通过在中间添加打印行来调试。它似乎一直工作到q1Ref（因为我可以用q1Ref打印firebase的https），然后它无法从这里输入代码：-q1Ref.observeSingleEvent（值：，带：{快照in@AppManiac上述代码的工作方式与直接从工作项目复制和粘贴的代码相同。我的答案中包含的输出是从XCode控制台实际复制和粘贴的结果。一个区别是，您的Firebase结构与您的问题中包含的结构略有不同。另一个问题是Firebase如何重新创建定义了f。我将它定义为'ref'的类变量，这样我就可以使用self.ref访问我的Firebase根引用。

Answer A is One character argues with another character who intrudes on her home.
Answer B is One character receives a surprising request from\nanother character
Answer C is One character reminisces about choices she has\nmade over the years.
Answer D is One character criticizes another character for\npursuing an unexpected course of action.
Answer E is null

class ViewController: UIViewController {
    var ref: DatabaseReference!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.ref = Database.database().reference()