想要从 firebase 获取用户数据到字典中答案

【问题标题】：want to fetch userdata from firebase into a dictionary想要从 firebase 获取用户数据到字典中
【发布时间】：2017-08-16 14:12:33
【问题描述】：

我希望你能帮助我：我尝试将用户数据从 firebase 数据库提取到用户类中并调用“setValuesForKeys”。我确实知道我的类属性必须与 firebase 字典中的完全一样，但我收到错误“此类不符合关键城市的键值编码。”

func fetchUsers(){
    Database.database().reference().child("users").observe(.childAdded, with: { (snapshot) in
        if let usersDictionary = snapshot.value as? [String: String] {
            let users = Userdata()
            users.setValuesForKeys(usersDictionary)
        }
    }, withCancel: nil)
}

我的用户类是

class Userdata: NSObject {
    var email: String?
    var password: String?
    var firstname: String?
    var lastname: String?
    var street: String?
    var streetno: String?
    var zipcode: String?
    var city: String?
    var phone: String?  }

firebase 的快照看起来像

Snap (ndLBXXX75Oe9Y1PXrqfISL8A4v82) {
city = Washington;
email = "1@a.com";
firstname = Andre;
lastname = Doe;
password = xxxxxx;
phone = "";
street = "Mainstreet";
streetno = 1;
zipcode = 11111;

}

数据库中的字典看起来像

["city": Washington, "firstname": Andre, "lastname": Doe, "email": 1@a.com, "password": xxxxxx, "streetno": 1, "phone": , "street": Mainstreet, "zipcode": 11111]

到目前为止，我有一个解决方案：

users.city = dictionary["city"]

我的问题/问题：我确实想了解错误消息“此类不符合关键城市的键值编码”背后的问题。因为类和 firebase 快照中的密钥看起来相同。

【问题讨论】：

这个错误是因为你正在尝试使用 KVC。在developer.apple.com/library/content/documentation/Cocoa/… 阅读有关 KVC 使用情况的信息。字典没有键城市、电子邮件的属性...这就是您看到错误的原因。您可以遍历字典中的所有键并使用 user.setValue(dictionary[key], forKey: key)
查看我的答案，它可以轻松地将快照转换为自定义类 - stackoverflow.com/a/38154998/2019221
@StasVolskiy 感谢您的回答和您的循环解决方案。它确实有效。我的解决方案是：user.firstname = usersDictionary["firstname"] 我已经阅读了这个developer.apple.com/documentation/objectivec/nsobject/…，我认为我可以使用字典键并将它们与我的类属性匹配。

标签： swift dictionary firebase firebase-realtime-database

【解决方案1】：

工作解决方案：我必须扩展我的用户类。现在，整个用户类看起来像：

代码如下：

 import Foundation

    class UserData: NSObject {
        var id: String?
        var email: String?
        var password: String?
        var salutation: String?
        var degree: String?
        var firstname: String?
        var lastname: String?
        var street: String?
        var streetno: String?
        var zipcode: String?
        var city: String?
        var phone: String?
        var profileImage: String?

    init(dictionary: [String: Any]) {
        self.city = dictionary["city"] as? String
        self.id = dictionary["id"] as? String
        self.email = dictionary["email"] as? String
        self.salutation = dictionary["salutation"] as? String
        self.degree = dictionary["degree"] as? String
        self.firstname = dictionary["firstname"] as? String
        self.lastname = dictionary["lastname"] as? String
        self.password = dictionary["password"] as? String
        self.phone = dictionary["phone"] as? String
        self.street = dictionary["street"] as? String
        self.streetno = dictionary["streetno"] as? String
        self.zipcode = dictionary["zipcode"] as? String
        self.profileImage = dictionary["profileImage"] as? String

    }
}

【讨论】：