swift - 在 Swift 中，如何将 CFStringRef[] 和 CFTypeRef[] 转换为 CMutablePointer< COpaquePointer >？

Question

在 Swift 中我如何转换 CFStringRef[]和 CFTypeRef[]至 CMutablePointer< COpaquePointer > ？

我想调用CFDictionaryCreate来自 swift 。我已经定义:

var keys: CFStringRef[] = [kCGImageSourceCreateThumbnailWithTransform, kCGImageSourceCreateThumbnailFromImageIfAbsent, kCGImageSourceThumbnailMaxPixelSize, kCGImageSourceCreateThumbnailFromImageAlways]

var values: CFTypeRef[] = [kCFBooleanTrue, kCFBooleanTrue, imageSize, kCFBooleanTrue]

CFDictionaryCreate(nil, keys, values, 4, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks)

但不知道如何在上述调用中指定键和值。

Answer 1

我可以通过为您创建不安全的指针让编译器停止提示，但我对 CFDictionary 的其余用法超出了我的理解范围。

import ImageIO

let dictionayKeyCB = UnsafePointer<CFDictionaryKeyCallBacks>()
let valueKeyCB = UnsafePointer<CFDictionaryValueCallBacks>()

let keys: [CFStringRef] = [kCGImageSourceCreateThumbnailWithTransform, kCGImageSourceCreateThumbnailFromImageIfAbsent, kCGImageSourceThumbnailMaxPixelSize, kCGImageSourceCreateThumbnailFromImageAlways]
let keysPointer =  UnsafeMutablePointer<UnsafePointer<Void>>.alloc(1)
keysPointer.initialize(keys)

let values: [CFTypeRef] = [kCFBooleanTrue, kCFBooleanTrue, kCFBooleanTrue, kCFBooleanTrue]
let valuesPointer =  UnsafeMutablePointer<UnsafePointer<Void>>.alloc(1)
valuesPointer.initialize(values)

CFDictionaryCreate(kCFAllocatorDefault, keysPointer, valuesPointer, 4, dictionayKeyCB, valueKeyCB)