Question

为什么我会在第34行收到此错误？ let postObject = [String：AnyObject] = [＆＃34;

无法赋值：函数调用返回不可变值

    @IBAction func HandleSendButton(_ sender: Any) {
    let postRef = Storage.storage().reference().child("messages").child("\(selectedUser).[“id”]")

    let postObject = [[String:AnyObject]]() = [
        "From": [
            "uid": User.uid,
            "username": User.username,
            "photoURL": User.photoURL.absoluteString
        ],
        "Message": textView.text,
        "timestamp": [".sv":"timestamp"]
        ] as [String:Any]

    postRef.setValue(postObject, withCompletionBlock: { error, ref in
        if error == nil {
            self.dismiss(animated: true, completion: nil)
        } else {
            // Handle the error
        }
    })
}

Answer 1

只需删除let postObject = [部分：

let postObject: [String: Any] = [

或

dpkg-query --showformat='${Version}' --show rabbitmq-server

Answer 2

应该是这样的：

let postObject

: [[String:AnyObject]]部分声明一个常量，=声明它的类型（注意不使用=），最后在for item1, item2, item3 in zip(list1, list2, list3): if item1 == item2: print(item3)之后是初始化它的文字对象。 / p>

Answer 3

有一些问题需要解决。

我们假设您的Firebase看起来像这样

def ninety_nine_bottles(n=99):
    for i in range(n, 0, -1):
        print(f'{i} bottles of beer on the wall, {i} of beer! You take one down, pass it around, {i-1} bottles of beer on the wall')

如果您想创建一个新问题节点，这将在该结构中创建

root
  questions
    uid_0
      From:
        photoUrl: "some photoUrl"
        uid: "some userid"
        username: "some username" 
      message: "some message"
      timestamp: "some timestamp"

有了这个，我们得到了uid并定义了对数据写入位置的引用。

然后简单使用字典; Firebase使用键：值对来存储它的数据，我们定义一个字典来包含一个键，它是一个字符串，值可以是一种Any。

let uid = Auth.auth().currentUser?.uid
let postRef = self.ref.child("questions").child(uid!) //self.ref is a class var*

let dict: [String: Any] = ["From":
    ["uid": "some uid",
     "username": "some username",
     "photoUrl": "some url"],
    "message": "some message",
    "timestamp": "some timestamp"
]

postRef.setValue(dict, withCompletionBlock: { error, ref in
    if error == nil {
        self.dismiss(animated: true, completion: nil)
    } else {
        // Handle the error
    }
})

这允许第一个元素是String：Dictionary，第二个和第三个元素是String：String。

* self.ref指向我的根Firebase节点。编辑指向你的。

Answer 4

试试这个：

    let postObject: [String: Any] = [
    "From": [
        "uid": User.uid,
        "username": User.username,
        "photoURL": User.photoURL.absoluteString
        ] as [String: Any],
    "Message": textView.text,
    "timestamp": [".sv":"timestamp"]
    ] as [String: Any]

必要的变更是：

删除最初的＆＃34; =＆＃34;和＆＃34;（）＆＃34;
替换＆＃34; [String：AnyObject]＆＃34;用＆＃34; [String：Any]＆＃34;
施放＆＃34; From＆＃34;字典值为＆＃34; as [String：Any]＆＃34;

请告诉我这是否适合您。

无法赋值：函数调用返回不可变值（[[String：AnyObject]]）

4 个答案: