Swift 3方法从字符串中创建utf8编码数据。

I know there's a bunch of pre Swift3 questions regarding NSData stuff. I'm curious how to go between a Swift3 String to a utf8 encoded (with or without null termination) to Swift3 Data object.

我知道有很多关于NSData的前Swift3问题。我很好奇，如何将Swift3字符串转换为utf8编码(带有或没有空终止)，以Swift3数据对象。

The best I've come up with so far is:

到目前为止我想到的最好的方法是:

let input = "Hello World"
let terminatedData = Data(bytes: Array(input.nulTerminatedUTF8))
let unterminatedData = Data(bytes: Array(input.utf8))

Having to do the intermediate Array() construction seems wrong.

必须做中间数组()构造似乎是错误的。

2 个解决方案

#1

It's simple:

很简单:

let input = "Hello World"
let data = input.data(using: .utf8)!

If you want to terminate data with null, simply append a 0 to it. Or you may call cString(using:)

如果您想终止带有null的数据，只需将一个0附加到它。或者您可以调用cString(使用:)

let cString = input.cString(using: .utf8)! // null-terminated

#2

NSString methods from NSFoundation framework should be dropped in favor for Swift Standard Library equivalents. Data can be initialized with any Sequence which elements are UInt8. String.UTF8View satisfies this requirement.

NSString方法从NSFoundation框架应该被放弃，以支持Swift标准库。数据可以用任何元素都是UInt8的序列初始化。字符串。UTF8View满足这个要求。

let input = "Hello World"
let data = Data(input.utf8)
// [72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100]

There is no such thing as null terminated data representation of a string. String null termination is an implementation detail of C language and it should not leak outside.

没有一个字符串的空终止数据表示。字符串null终止是C语言的一个实现细节，它不应该在外部泄漏。

If you are planning to work with C APIs, please take a look the following property of String type:

如果您打算使用C api，请查看以下字符串类型的属性:

public var utf8CString: ContiguousArray<CChar> { get }

#1