Question

我有这个结构：

struct MessageRandomWords {
        let message = MessageType.kMessageTypeRandomWords
        let randomWords : Array<Array<String>>
    }

我试图通过这样做将此结构转换为NSDate：

    var message = MessageRandomWords(randomWords: self.words)
    let data = NSData(bytes: &message, length: sizeof(MessageRandomWords))

但是，当我试图将其转换回原始结构时：

var messageRandomWords : MessageRandomWords?
                data.getBytes(&messageRandomWords, length: sizeof(MessageRandomWords))
                if let messageRandomWords = messageRandomWords {

}

我在if let语句中得到了BAD_ACCESS错误。问题在哪里？

Answer 1

根据这个答案： Swift structs to NSData and back 我写了这个解决方案：

struct MessageRandomWords {
    let message = MessageType.kMessageTypeRandomWords
    var data : NSData?
    var name: String

    struct ArchivedPacket {
        let message = MessageType.kMessageTypeRandomWords
        var dataLength : Int64
        var nameLength : Int64
    }

    func archive() -> NSData {
        var archivedPack = ArchivedPacket(dataLength: Int64(self.data!.length), nameLength: Int64(self.name.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)))
        var metaData = NSData(bytes: &archivedPack, length: sizeof(ArchivedPacket))
        let archiveData = NSMutableData(data: metaData)
         archiveData.appendData(name.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!)
        archiveData.appendData(data!)
        return archiveData
    }

    static func unarchive(data : NSData!) -> MessageRandomWords {
        var archivedPacket = ArchivedPacket(dataLength: 0, nameLength: 0)
        let archivedStructLength = sizeof(ArchivedPacket) //lenght of the struct

        //Get the data tha will form our archived Packet
        let archivedData = data.subdataWithRange(NSMakeRange(0, archivedStructLength))
        //save the data taht form the archivedPacket inside the archivedPacket
        archivedData.getBytes(&archivedPacket, length: archivedStructLength)
        //get the range of data that contains the name
        let nameRange = NSMakeRange(archivedStructLength, Int(archivedPacket.nameLength))
        //get the range of the data that contains the data
        let dataRange = NSMakeRange(archivedStructLength + Int(archivedPacket.nameLength), Int(archivedPacket.dataLength))
        //get the data that rappresent the name
        let nameData = data.subdataWithRange(nameRange)
        //Get the name frome the data
        let name = NSString(data: nameData, encoding: NSUTF8StringEncoding) as! String
        // Geth the data
        let theData = data.subdataWithRange(dataRange)

        //Create the struct
        let messageRndm = MessageRandomWords(data: theData, name: name)
        return messageRndm
    }

}

如果您按照显示的方式创建结构，则可以通过将其编码为NSData来发送您的字符串数组，然后在接收时对其进行解码。

您可以在GitHub

上找到完整的工作示例

如果您有更好的解决方案，请留下一些反馈

如何使用字符串数组将结构转换为NSData，反之亦然Swift

1 个答案: