如何在OS X目标中创建CFDictionary？

Question

根据文档 CFDictionaryCreate用于实例化CFDictionary swift.

func CFDictionaryCreate(_ allocator: CFAllocator!,
                  _ keys: UnsafeMutablePointer<UnsafePointer<Void>>,
                  _ values: UnsafeMutablePointer<UnsafePointer<Void>>,
                  _ numValues: CFIndex,
                  _ keyCallBacks: UnsafePointer<CFDictionaryKeyCallBacks>,
                  _ valueCallBacks: UnsafePointer<CFDictionaryValueCallBacks>) -> CFDictionary!

我怎样才能创建keys和values参数？到目前为止,我已尝试使用swift的String类型,希望它会自动转换为适当的类型:

import Foundation

var keys : [String] = ["key1", "key2"]
var values : [String] = ["value1", "value2"]
var keyCallbacks = kCFTypeDictionaryKeyCallBacks
var valueCallbacks = kCFTypeDictionaryValueCallBacks
var dict : CFDictionary = CFDictionaryCreate(kCFAllocatorDefault,
    &keys, &values, 2, &keyCallbacks, &valueCallbacks)

不幸的是我收到一个错误,说String不是keys和values数组元素的正确类型:

main.swift:41:2: error: 'String' is not identical to 'UnsafePointer<Void>'
    &configKeys, &configValues, 3, &keyCallbacks, &valueCallbacks)

如何使一个UnsafePointer<Void>从String？

Answer 1

对于Swift 3,你需要额外的施法CFDictionary.否则,上下文类型'CFDictionary'不能与字典文字一起使用.

let options: CFDictionary = [kSecImportExportPassphrase as String : "certificateKey"] as CFDictionary

有关更多信息,请参阅https://bugs.swift.org/browse/SR-2388.