ios - 试图快速从firebase数据库中获取用户
<p><p>尝试快速从 firebase 数据库中获取用户,但我收到错误 <code>此类与键的键值编码不兼容</code>。我不认为我做错了什么,因为它不是我的第一个应用程序。我能够以完全相同的方式在其他应用程序中获取用户。但它现在不工作。所有必要的细节如下。请帮助,谢谢
这是代码</p>
<pre><code>func fetchUsers() {
Database.database().reference().child("Users").observe(.childAdded, with: { (snapshot) in
if let dictionary = snapshot.value as? {
print(snapshot)
let user = Users()
user.setValuesForKeys(dictionary)
//print(user.Email ?? "")
//print(user.Name ?? "")
}
}, withCancel: nil)
}
</code></pre>
<p>这是模型:</p>
<pre><code>import UIKit
class Users: NSObject {
var Name : String?
var Email : String?
}
</code></pre>
<p>数据库截图
<a href="/image/R3F5t.png" rel="noreferrer noopener nofollow"><img src="/image/R3F5t.png" alt="enter image description here"/></a> </p>
<p>控制台出错</p>
<blockquote>
<p>ChatHub <strong>* Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key Email.'
*</strong> First throw call stack:
(0x182dd7d38 0x1822ec528 0x182dd7a00 0x1836e3780 0x18377fc0c 0x1048000d8 0x104800174 0x1048ac760 0x1048d7e40 0x105b0d49c 0x105b0d45c 0x105b12050 0x182d7ff20 0x182d7dafc 0x182c9e2d8 0x184b2ff84 0x18c24b880 0x104806a64 0x1827c256c)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) </p>
</blockquote></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>在我看来,您不应该在开头使用大写字母命名您的实例/对象/变量,请参阅:<a href="https://softwareengineering.stackexchange.com/questions/202031/what-is-the-reason-for-using-lowercase-for-the-first-word-in-a-local-variable-e" rel="noreferrer noopener nofollow">https://softwareengineering.stackexchange.com/questions/202031/what-is-the-reason-for-using-lowercase-for-the-first-word-in-a-local-variable-e</a> .</p>
<p>回到您的问题,您是否尝试过重命名 <code>Users</code> 的属性?尽量使用<code>Struct</code>,不需要像这样使用<code>NSObject</code>的类和子类,方便初始化。我怀疑您的 <code>Email</code> 变量名称是导致错误的原因。</p>
<pre><code>struct Users {
var name: String?
var email: String?
}
</code></pre>
<p><code>Users</code> 的新实例:</p>
<pre><code>let user = Users(name: "name here", email: "email here")
</code></pre>
<p>我希望这会有所帮助!</p></p>
<p style="font-size: 20px;">关于ios - 试图快速从firebase数据库中获取用户,我们在Stack Overflow上找到一个类似的问题:
<a href="https://stackoverflow.com/questions/46877135/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/46877135/
</a>
</p>
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