我正在从Firebase检索数据，然后将收到的FIRDataSnapshot类型的数组转换为[String：Any]类型的字典数组。 如何将这个字典数组输出到有序列表中的Xcode项目中的.txt文件中？
txt文件中打印的输出应采用以下格式：
预订1：
EmailAddress：johnmm@gmail.com
电话号码：94949392
。
。
预订4：
EmailAddress：chris@gmail.com
电话号码：202583963
在我的问题的底部，您会在finalDictionary
我认为逻辑应该是这样的：
1.遍历finalDictionary的元素
2.取数组的每个元素，为它指定一个计数+断行
let finalDictionary = [String:Any]()
func startObservingDB() {
dbRef.child(FullData.uid!).observe(.value, with: { (snapshot: FIRDataSnapshot) in
// an instance of FireBaseData holding all bookings under currentUid
var newBookingInfo = [FireBaseData]()
//iterate over all children under /FullData.uid! path
for customer in snapshot.children {
//the customer node starting with cus...
let customerObject = customer as! FIRDataSnapshot
//customer key
self.customerKey = customerObject.key
print("this is the Stripe customer that can be charged \(customerObject.key)")
//now iterate over each booking which is located under customerObject in Firebase
for booking in customerObject.children {
// after each iteration through snapshot.children, create an instance of FireBaseData with 'booking' for the current iteration & assign it to bookingItem
var bookingItem = FireBaseData(snapshot: booking as! FIRDataSnapshot)
//assign key of the parent to each booking
bookingItem.Key = self.customerKey
// append the bookingItem after each iteration to newBookingInfo array
newBookingInfo.append(bookingItem)
} // end of for booking in myCustomer
} // end of for customer in snapshot.children
//assign newBookingInfo to global variable bookingInfo so it can be used globally within the class
self.bookingInfo = newBookingInfo
// sort the array in place so that the most recent date will appear first
self.bookingInfo.sort(by: {(DateAndTimeObject_1,DateAndTimeObject_2) -> Bool in
DateAndTimeObject_1.TimeStampDateAndTime > DateAndTimeObject_2.TimeStampDateAndTime
})
// convert bookingInfo of type FIrebaseData to Array of Dictionaries
let arrayOfDictionary = self.bookingInfo.flatMap { $0.toAnyObject() as? [String:Any] }
finalDictionary = arrayOfDictionary
print("arrayOfDictionary is \(arrayOfDictionary)")
//I can write a string to a file in Xcode project using the code snippet
//below, but this does not solve my problem, namely to output all elements
//of the array as specified above with a break space after each element
//so that they can be in a human readable format.
let fileName = "myBookings"
let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
// If the directory was found, we write a file to it
if let fileURL = dir?.appendingPathComponent(fileName).appendingPathExtension("txt") {
// Write to the file
let outString = "Write this text to the file"
do {
try outString.write(to: fileURL, atomically: true, encoding: .utf8)
} catch {
print("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
}
}
self.tableView.reloadData()
}, withCancel: { (Error:Any) in
print("Error firebase \(Error)")
})
} // end of startObservingDB()
func exportBookings(){
let path = URL(string: "file:///Users/bogdanbarbulescu/Desktop/Test.txt")
//writing
do {
try (finalDictionary).description.write(to: path!, atomically: false, encoding: .utf8)
}
catch let error { print("The error is \(error.localizedDescription)")
}
}
print的输出（“arrayOfDictionary is（arrayOfDictionary）”）是：
arrayof Dict是[[“EmailAddress”：johnmm @ gmail.com，“PhoneNumber”： 94949392，“PaymentID”：ch_1AVK6KLCZ34Ur7XGsbROjWhe，“BookingAmount”： 37，“BookingCompleted”：0，“NoteInstructions”：带狗出去 请，“insideCabinets”：true，“BookingNumber”：883924391， “BookingStatusAdmin”：0，“insideFridge”：true，“FrequencyName”：Every 2周，“EntryInstructions”：地毯下的钥匙，“FullName”：詹姆斯， “SuppliesAmount”：0，“FirebaseUserID”：7b1eRsa9QWhdtA5EwyD2FiPZHSh2， “TimeStampDateAndTime”：1497790800，“PostCode”：W3 7RZ， “SelectedBathRow”：2，“FrequecyAmount”：22，“laundryWash”：false， “StreetAddress”：11 High St，“CostToRescheduleClient”：0， “BookingStatusClient”：1，“TimeStampBookingSavedInDB”：1497618179， “FlatNumber”：孤独，“SelectedBedRow”：1，“interiorWindows”：0， “CostToCancelClient”：0，“DoormanOption”：隐藏密钥，“DateAndTime”： 2017年6月18日星期日14:00，“insideOven”：真实，“SuppliesName”：我有 清洁用品]，
[“EmailAddress”：johnmm @ gmail.com，“PhoneNumber”：07476953923， “PaymentID”：ch_1ATTRHLCZ34Ur7XGL2CGN1I3，“BookingAmount”：63， “BookingCompleted”：0，“NoteInstructions”：不，“insideCabinets”：是的， “BookingNumber”：173009560，“BookingStatusAdmin”：1，“insideFridge”： true，“FrequencyName”：每两周一次，“EntryInstructions”：simbasdada， “CostToRescheduleAdmin”：0，“FullName”：John Luch，“SuppliesAmount”： 5，“FirebaseUserID”：7b1eRsa9QWhdtA5EwyD2FiPZHSh2， “TimeStampDateAndTime”：1497632400，“PostCode”：IG11 6PP， “SelectedBathRow”：2，“FrequecyAmount”：33，“洗衣粉”：真的， “StreetAddress”：High St，“CostToRescheduleClient”：0， “BookingStatusClient”：1，“TimeStampBookingSavedInDB”：1497177419， “FlatNumber”：Flat 11，“SelectedBedRow”：2，“interiorWindows”：0， “DoormanOption”：隐藏密钥，“DateAndTime”：星期五，2017年6月16日18:00， “insideOven”：false，“SuppliesName”：带清洁用品]]
答案 0 :(得分：1)
如果您只想以“有序/可读”的格式输出您的词典数组，您可以使用：
if let orderedKeys = finalDictionary.first?.keys {
var outputString = ""
var i = 1
for d in finalDictionary {
outputString += "Booking \(i):\n"
for k in orderedKeys {
outputString += k + ": " + (d[k] ?? "(no value)") + "\n"
}
outputString += "\n"
i += 1
}
print(outputString)
// or, write outputString to a text file
}
注意：这只是快速代码...不一定是最佳的或100％无错误，并假设所有记录具有相同的密钥。更多的是“这里是一个方向去”有点儿的事情：）
编辑：如果字典可能包含可变的键集，则可以执行以下操作：
var outputString = ""
var i = 1
for d in finalDictionary {
outputString += "Booking \(i):\n"
for k in d.keys {
outputString += k + ": " + (d[k] ?? "(no value)") + "\n"
}
outputString += "\n"
i += 1
}
print(outputString)
编辑2：可能有点“快捷”的做法：
outputString = ""
i = 1
finalDictionary.forEach {
outputString += "Booking \(i):\n"
$0.forEach { outputString += "\($0): \($1)\n" }
outputString += "\n"
i += 1
}
print(outputString)
因为字典是无序的，所以最终可能会：
Booking 1:
EmailAddress: johnmm@gmail.com
PhoneNumber: 94949392
FullName: John
.
Booking 2:
SomeOtherKey: Some Value
FullName: Dave
EmailAddress: dave@gmail.com
.
Booking 3:
FullName: Chris
PhoneNumber: 202583963
SomeOtherKey: Some Other Value
EmailAddress: chris@gmail.com
等等。