如何将字符串转换为UnsafePointer 和长度

  • Z时代
  • 2024-01-10
  • 分类：问答

当我使用NSOutputStream的write方法时

func write(_ buffer: UnsafePointer<UInt8>, maxLength length: Int) -> Int

我不知道如何转换String 为UnsafePointer<UInt8>和长度

如何迅速做到这一点？

回答：

您必须先将字符串转换为UTF-8数据

let string = "foo bar"
let data = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!

然后将其写入输出流

let outputStream: NSOutputStream = ... // the stream that you want to write to
let bytesWritten = outputStream.write(UnsafePointer(data.bytes), maxLength: data.length)

该UnsafePointer()转换是必要的，因为data.bytes有型UnsafePointer<Void>，而不是UnsafePointer<UInt8>如预期的write()

方法。

let string = "foo bar"
// Conversion to UTF-8 data (cannot fail):
let data = string.data(using: String.Encoding.utf8)!
// Write to output stream:
let outputStream: NSOutputStream = ... // the stream that you want to write to
let bytesWritten = data.withUnsafeBytes { outputStream.write($0, maxLength: data.count) }

以上是 如何将字符串转换为UnsafePointer 和长度 的全部内容， 来源链接： utcz.com/qa/406345.html

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