问题描述
伙计们，所以我一直在尝试将这个Objective-C代码转换为快速代码，但始终会遇到麻烦。以下是目标C代码：
Hey guys so I've been trying to convert this objective-c code to swift but keep stumbling on problems with it. Heres the objective-c code:
int msgLength = *((int *) _inputBuffer.bytes);
msgLength = ntohl(msgLength);
，这里是我设法得到的东西：
and heres what I managed to get:
var msgLength = (inputBuffer.bytes).load(as: Int.self)
msgLength = Int(NSSwapBigLongToHost(UInt(msgLength)))
但这不起作用，它崩溃表示没有足够的位数。非常感谢您的帮助！
but this isn't working, it crashes saying there isn't enough bits. I really appreciate the help thanks!
推荐答案
C int 类型为一个32位整数（在当前所有Apple平台上）为
，而Swift Int 在64位平台上为64位整数。
The C int type is a 32-bit integer (on all current Apple platforms),whereas the Swift Int is 64-bit integer on 64-bit platforms.
因此，在Swift中，您必须对32位整数使用 UInt32 ：
Therefore in Swift you'll have to use UInt32 for 32-bit integers:
var msgLength = (inputBuffer.bytes).load(as: UInt32.self)
msgLength = UInt32(bigEndian: msgLength)
或者，如果您从 NSData 切换到 Data ：
Or, if you switch from NSData to Data:
let msgLength = UInt32(bigEndian:inputBuffer.withUnsafeBytes { $0.pointee })
（即使在C代码 uint32_t 中也更合适比 int 强调读取4个字节。）
(Even in the C code uint32_t would be better suited than int to emphasize that 4 bytes are read.)
这篇关于Swift 4将字节转换为Int和Ntohl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！