swift - 如何在 Swift 的 NSNetService 上使用 getInputStream()？

Question

我正在尝试设置一个 NSInputStream和 NSOutputStream用于 NSNetService 上的 Bonjour 连接. getInputStream 方法需要类型为 UnsafeMutablePointer<NSInputStream?> 的参数:

public func getInputStream(inputStream: UnsafeMutablePointer<NSInputStream?>, outputStream: UnsafeMutablePointer<NSOutputStream?>) -> Bool

但是当我这样做时，inputStream 和 outputStream 保持为 nil，succes 为 false:

    let inputStream:UnsafeMutablePointer<NSInputStream?> = nil
    let outputStream:UnsafeMutablePointer<NSOutputStream?> = nil

    var succes = service.getInputStream(inputStream, outputStream: outputStream)

另一个问题是我不能将它作为“NSInputStream”来处理，因为它的类型是“UnsafeMutablePointer”。当我尝试这样做时，出现以下错误:

Error:(52, 13) value of type 'UnsafeMutablePointer<NSInputStream?>' (aka 'UnsafeMutablePointer<Optional<NSInputStream>>') has no member 'delegate'

在 swift 中处理这些可变指针类型的正确方法是什么？任何帮助将不胜感激，谢谢!

Answer 1

你的指针是nil 因为你没有为它们分配内存。但更简单的解决方案是将 NSIn/OutputStream? 变量作为带有 & 的 inout 参数:

var inputStream : NSInputStream?
var outputStream : NSOutputStream?

let success = service.getInputStream(&inputStream, outputStream: &outputStream)