如何将字典数组写入Xcode项目中的.txt文件

Question

我从Firebase检索数据，然后将收到的类型为FIRDataSnapshot的数组转换为类型为[String：Any]的字典数组。 如何将这个字典数组输出到我的Xcode项目中的.txt文件的有序列表中？

输出在txt文件印刷应该在这个格式：

预订1：
EmailAddress的：johnmm@gmail.com
电话号码：94949392
。
。
预订4：
EmailAddress的：chris@gmail.com
电话号码：202583963

我的问题的底部，你会发现原始数据，它的外观在finalDictionary

我觉得逻辑应是这样的： 1.遍历的finalDictionary 2.元素采取数组的每个元素，分配一个计数到它+断裂线

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)") 
    } 
} 

打印的输出（ “arrayOfDictionary是（arrayOfDictionary）”）是：

arrayof字典是[[ “EmailAddress的”：johnmm@gmail.com， “******中国”： 94949392， “PaymentID”：ch_1AVK6KLCZ34Ur7XGsbROjWhe “BookingAmount”： 37，“BookingCompleted”：0，“NoteInstructions”：请把狗取出 please，“insideCabinets”：true，“BookingNumber”：883924391, “BookingStatusAdmin”：0，“insideFridge”：true， “FrequencyName”：每个 2周，“EntryInstructions”：地毯下的键，“FullName”：James， “SuppliesAmount”：0，“FirebaseUserID”：7b1eRsa9QWhdtA5EwyD2FiPZHSh2, “TimeStampDate AndTime“：1497790800，”PostCode“：W3 7RZ， ”SelectedBathRow“：2，”FrequecyAmount“：22，”laundryWash“：false， ”StreetAddress“：11 High St，”CostToRescheduleClient“：0, ”BookingStatusClient“ ：1，“TimeStampBookingSavedInDB”：1497618179, “FlatNumber”：Conely，“SelectedBedRow”：1，“interiorWindows”：0, “CostToCancelClient”：0，“DoormanOption”：隐藏键，“DateAndTime”： Sun， 2017年6月18日14:00，“insideOven”：true，“SuppliesName”：我有 清洁用品]，

[“EmailAddress”：johnmm @ gmail。COM， “******中国”：07476953923， “PaymentID”：ch_1ATTRHLCZ34Ur7XGL2CGN1I3， “BookingAmount”：63， “BookingCompleted”：0， “NoteInstructions”：不， “insideCabinets”：真实， “BookingNumber”：173009560， “BookingStatusAdmin” ：1，“insideFridge”： true，“FrequencyName”：每2周“EntryInstructions”：simbasdada， “CostToRescheduleAdmin”：0，“FullName”：John Luch，“SuppliesAmount”： 5，“FirebaseUserID”：7b1eRsa9QWhdtA5EwyD2FiPZHSh2 ， “TimeStampDateAndTime”：1497632400， “邮编”：IG11 6PP， “SelectedBathRow”：2 “FrequecyAmount”：33， “laundryWash”：真， “的StreetAddress”：高圣， “CostToRescheduleClient”：0， “ BookingStatusClient“：1，”TimeStampBookingSavedInDB“：1497177419， “FlatNumber”：Flat 11，“SelectedBedRow”：2，“interiorWindows”：0， “DoormanOption”：隐藏键，“DateAndTime”：2017年6月16日星期五18:00， “insideOven”：false， SuppliesName“：把清洁用品]

Answer 1

如果你想要做的是你在字典的阵列输出‘有序/可读’的格式，您可以使用此：

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：此只是快速代码...不一定是最佳的或100％无错，并假定所有记录具有相同的密钥。更多的是“这里有一个方向去”还挺啄:)

编辑：大概：如果字典可以具有可变的钥匙套的，你可以这样做：

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这样做有点“Swiftier”的方式：

：

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，你可能会结束

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。