问题描述
对于此 Firebase 数据拉取，我错误地使用了以下代码中的下标，但我无法弄清楚我做错了什么.我收到一个错误:let uniqueID = each.value["Unique ID Event Number"] as！Int 行.
I am using the subscript in the following code incorrectly for this Firebase data pull, but I can't figure out what I am doing wrong. I get an error of Ambiguous use of subscript for the let uniqueID = each.value["Unique ID Event Number"] as! Int line.
// Log user in
if let user = FIRAuth.auth()?.currentUser {
let uid = user.uid
// values for vars sevenDaysAgo and oneDayAgo set here
...
let historyRef = self.ref.child("historyForFeedbackLoop/(uid)")
historyRef.queryOrdered(byChild: "Unix Date").queryStarting(atValue: sevenDaysAgo).queryEnding(atValue: oneDayAgo).observeSingleEvent(of: .value, with: { snapshot in
if (snapshot.value is NSNull) {
print("user data not found")
}
else {
if let snapDict = snapshot.value as? [String:AnyObject] {
for each in snapDict {
// Save the IDs to array.
let uniqueID = each.value["Unique ID Event Number"] as! Int
self.arrayOfUserSearchHistoryIDs.append(uniqueID)
}
}
else{
print("SnapDict is null")
}
}
})
}
我尝试应用我从这篇帖子中学到的知识，但我无法弄清楚我错过了什么，因为我以为我让编译器知道它是什么类型的字典，带有as?[String:AnyObject]"
I tried to applying what I learned from this post, but I couldn't figure out what I am missing because I thought I was letting the compiler know what type of dictionary it is with the "as? [String:AnyObject]"
任何想法或想法将不胜感激！
Any thoughts or ideas would be greatly appreciated!
推荐答案
我处理数据的首选方式是尽可能晚地打开 FIRDataSnapshot.
My preferred way of dealing with data is to unwrap the FIRDataSnapshot as late as possible.
ref!.observe(.value, with: { (snapshot) in
for child in snapshot.children {
let msg = child as! FIRDataSnapshot
print("(msg.key): (msg.value!)")
let val = msg.value! as! [String:Any]
print("(val["name"]!): (val["message"]!)")
}
})
这篇关于下标的歧义使用 (Swift 3)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！