Ios NSData在发送到其他设备后丢失

在设备之间传输时数据丢失。怀疑它真的丢失了-我肯定我做错了什么-但是什么

4分步骤进行。前3个步骤非常有效，我能够验证数据是否可以被解析（在发送之前）我收到数据，但不是全部？解析时，我可以确认数据类型，但不能确认类别信息（性别、类别、子类别）-为什么？步骤如下：

生成和存储数据（本地）

验证数据是否正确存储

将数据发送到其他设备（iPhone）

接收数据和分析信息-->失败

1。生成数据

func selectCategories(){
    //Fixed data for testing
    let gender = "Women"
    let category = "Shoes"
    let subCategory = "Pumps"

    print("SENDING - Gender: \(gender), Category: \(category), SubCategory: \(subCategory)")

    sendCategories(gender, category: category, subCategory: subCategory)

}

func sendData(data: NSData) {
    print("SENDING DATA")
    var sendDataError: NSError?
    let gameKitHelper = GameKitHelper.sharedInstance

    if let multiplayerMatch = gameKitHelper.multiplayerMatch {
        do {
            try multiplayerMatch.sendDataToAllPlayers(data, withDataMode: GKMatchSendDataMode.Reliable)
        } catch let error as NSError {
            print("Error while sending data: \(error)")
        } catch {
            print("Catch all errors: \(error)")
        }
    }
}

2。验证存储的数据

func sendCategories(gender: String, category: String, subCategory: String){
    var messageCategory = MessageCategory(message: Message(messageType: MessageType.Category), gender: gender, category: category, subCategory: subCategory)
    let data = NSData(bytes: &messageCategory, length: sizeof(MessageCategory))
    print("SEND - LENGTH: \(data.length)")

    // VERIFY DATA STORED SUCCESFULLY (FOR TESTING PURPOSES ONLY)
    let messageCategoryFromData = UnsafePointer<MessageCategory>(data.bytes).memory
    if messageCategoryFromData.message.messageType == MessageType.Category{

    print("SENDING - Gender: \(messageCategoryFromData.gender), Category: \(messageCategoryFromData.category), SubCategory: \(messageCategoryFromData.subCategory)")

    let temp_gender = messageCategoryFromData.gender
    let temp_category = messageCategoryFromData.category
    let temp_subCategory = messageCategoryFromData.subCategory
    let message = messageCategoryFromData.message

    // SUCCESSFULLY PRINTS THE GENDER ETC WITH CORRECT INFORMATION -> DATA PARSING WORKS PRIOR TO SENDING DATA
    print("RECEIVED (PRIOR TO SENDING). Gender: \(temp_gender) Category: \(temp_category) SubCategory: \(temp_subCategory)")
    }
    else{
        print("WRONG MESSAGE TYPE")
    }

    // SEND THE DATA
    sendData(data)
}

4。接收数据和分析信息（错误）

---

我稍微修改了你的代码

import XCPlayground
import Foundation

enum MessageType: Int {
    case RandomNumber, Category, GameBegin, Move, LapComplete, GameOver
}

struct Message {
    let messageType: MessageType
}

struct MessageCategory {
    let message: Message
    let gender: String
    let category: String
    let subCategory: String
}

func sendCategories(gender: String, category: String, subCategory: String)->NSData {
    var messageCategory = MessageCategory(message: Message(messageType: MessageType.Category), gender: gender, category: category, subCategory: subCategory)
    let data = NSData(bytes: &messageCategory, length: sizeof(MessageCategory))
    print("SEND - LENGTH: \(data.length)")

    // VERIFY DATA STORED SUCCESFULLY (FOR TESTING PURPOSES ONLY)
    let messageCategoryFromData = UnsafePointer<MessageCategory>(data.bytes).memory
    if messageCategoryFromData.message.messageType == MessageType.Category{

        print("SENDING - Gender: \(messageCategoryFromData.gender), Category: \(messageCategoryFromData.category), SubCategory: \(messageCategoryFromData.subCategory)")

        let temp_gender = messageCategoryFromData.gender
        let temp_category = messageCategoryFromData.category
        let temp_subCategory = messageCategoryFromData.subCategory
        let message = messageCategoryFromData.message

        // SUCCESSFULLY PRINTS THE GENDER ETC WITH CORRECT INFORMATION -> DATA PARSING WORKS PRIOR TO SENDING DATA
        print("RECEIVED (PRIOR TO SENDING). Gender: \(temp_gender) Category: \(temp_category) SubCategory: \(temp_subCategory)")
    }
    else{
        print("WRONG MESSAGE TYPE")
    }

    // SEND THE DATA
    //sendData(data)
    return data
}

let data = sendCategories("gender", category: "category", subCategory: "subcategory")

func matchReceivedData(data: NSData, fromPlayer player: String) {

    var message = UnsafePointer<Message>(data.bytes).memory

    if message.messageType == MessageType.Category {

        let messageCategory = UnsafePointer<MessageCategory>(data.bytes).memory

        print("MESSAGE: \(messageCategory.message)")
        print("DATA TYPE: \(messageCategory.message.messageType)")
        print("RECEIVED - LENGTH: \(data.length)")

        let gender = messageCategory.gender
        let category = messageCategory.category
        let subCategory = messageCategory.subCategory


        print("RECEIVING - Gender: \(gender), Category: \(category), subCategory: \(subCategory)")
    }
}

matchReceivedData(data, fromPlayer: "player")

/*
SEND - LENGTH: 80
SENDING - Gender: gender, Category: category, SubCategory: subcategory
RECEIVED (PRIOR TO SENDING). Gender: gender Category: category SubCategory: subcategory
MESSAGE: Message(messageType: MessageType.Category)
DATA TYPE: Category
RECEIVED - LENGTH: 80
RECEIVING - Gender: gender, Category: category, subCategory: subcategory
*/

---

错误是我使用了

Struct

来处理数据。但是在阅读之后，我意识到结构只是指向数据。这导致我的

String

数据没有与NSData一起发送（

Float

和

Int

工作正常）

---

解决方案是不使用struct来处理对象数据，而是将其作为原始NSData传递，然后始终包含一部分数据，该部分数据告诉它是哪种类型的数据，然后使用正确的解析。

尝试在步骤4中进行更改：删除

var message=UnsafePointer（data.bytes）.memory

并在那里添加一行

let messageCategory=UnsafePointer（data.bytes）.memory

。同时将if改为

if messageCategoryFromData.message.messageType==messageType.Category

谢谢@sunshine的建议。但是我需要第一个

var message=UnsafePointer（data.bytes.memory）

来测试接收到哪种类型的数据，然后正确地解析它。关于什么可能会干扰发送或接收的任何其他想法？谢谢重新编码。我也意识到错误在发送或接收部分的某个地方，因为我的步骤2正确地解析了信息。“匹配”用于代码的另一部分，我在这里没有展示它以减少混乱。知道发送或接收的问题是什么吗？上面的步骤4

matchReceivedData

介绍了接收部分。是

GameKit

的功能部分，当另一台设备在游戏期间接收数据时，会自动调用该功能。正如您可以看到的那样，如果message.messageType==messageType.Category起作用，则

。但是
让gender=messageCategory.gender
等变为零。我现在不明白为什么会这样：（@PederWessel）唯一的答案是，在你接收数据时，它实际上是零。这就是为什么我给你发了一个正确数据的例子。
enum MessageType: Int {
    case RandomNumber, Category, GameBegin, Move, LapComplete, GameOver
}

struct Message {
    let messageType: MessageType
}

struct MessageCategory {
    let message: Message
    let gender: String
    let category: String
    let subCategory: String
}

import XCPlayground
import Foundation

enum MessageType: Int {
    case RandomNumber, Category, GameBegin, Move, LapComplete, GameOver
}

struct Message {
    let messageType: MessageType
}

struct MessageCategory {
    let message: Message
    let gender: String
    let category: String
    let subCategory: String
}

func sendCategories(gender: String, category: String, subCategory: String)->NSData {
    var messageCategory = MessageCategory(message: Message(messageType: MessageType.Category), gender: gender, category: category, subCategory: subCategory)
    let data = NSData(bytes: &messageCategory, length: sizeof(MessageCategory))
    print("SEND - LENGTH: \(data.length)")

    // VERIFY DATA STORED SUCCESFULLY (FOR TESTING PURPOSES ONLY)
    let messageCategoryFromData = UnsafePointer<MessageCategory>(data.bytes).memory
    if messageCategoryFromData.message.messageType == MessageType.Category{

        print("SENDING - Gender: \(messageCategoryFromData.gender), Category: \(messageCategoryFromData.category), SubCategory: \(messageCategoryFromData.subCategory)")

        let temp_gender = messageCategoryFromData.gender
        let temp_category = messageCategoryFromData.category
        let temp_subCategory = messageCategoryFromData.subCategory
        let message = messageCategoryFromData.message

        // SUCCESSFULLY PRINTS THE GENDER ETC WITH CORRECT INFORMATION -> DATA PARSING WORKS PRIOR TO SENDING DATA
        print("RECEIVED (PRIOR TO SENDING). Gender: \(temp_gender) Category: \(temp_category) SubCategory: \(temp_subCategory)")
    }
    else{
        print("WRONG MESSAGE TYPE")
    }

    // SEND THE DATA
    //sendData(data)
    return data
}

let data = sendCategories("gender", category: "category", subCategory: "subcategory")

func matchReceivedData(data: NSData, fromPlayer player: String) {

    var message = UnsafePointer<Message>(data.bytes).memory

    if message.messageType == MessageType.Category {

        let messageCategory = UnsafePointer<MessageCategory>(data.bytes).memory

        print("MESSAGE: \(messageCategory.message)")
        print("DATA TYPE: \(messageCategory.message.messageType)")
        print("RECEIVED - LENGTH: \(data.length)")

        let gender = messageCategory.gender
        let category = messageCategory.category
        let subCategory = messageCategory.subCategory


        print("RECEIVING - Gender: \(gender), Category: \(category), subCategory: \(subCategory)")
    }
}

matchReceivedData(data, fromPlayer: "player")

/*
SEND - LENGTH: 80
SENDING - Gender: gender, Category: category, SubCategory: subcategory
RECEIVED (PRIOR TO SENDING). Gender: gender Category: category SubCategory: subcategory
MESSAGE: Message(messageType: MessageType.Category)
DATA TYPE: Category
RECEIVED - LENGTH: 80
RECEIVING - Gender: gender, Category: category, subCategory: subcategory
*/

func matchReceivedData(match: GKMatch, data: NSData, fromPlayer player: String)