如何将数组转换为UnsafeMutablePointer <UnsafeRawPointer？> Swift 3.0？

Question

这是我在Swift的早期版本中可行的代码:

 let imageOptionsDictKeys = [ kCVPixelBufferPixelFormatTypeKey, kCVPixelBufferWidthKey,  kCVPixelBufferHeightKey, kCVPixelBufferOpenGLESCompatibilityKey, kCVPixelBufferIOSurfacePropertiesKey]
 let imageOptionsDictValues = [ cvPixelFormatType,  frameW, frameH, boolYES]

 var keyCallbacks = kCFTypeDictionaryKeyCallBacks
 var valueCallbacks = kCFTypeDictionaryValueCallBacks

 let imageOptions = CFDictionaryCreate(kCFAllocatorDefault, UnsafeMutablePointer(imageOptionsDictKeys), UnsafeMutablePointer(imageOptionsDictValues), 4, &keyCallbacks, &valueCallbacks)

在Swift 3.0中进行更改后,我必须将我的键和值数组转换UnsafeMutablePointer<UnsafeRawPointer?>为创建CFDictionary.

这条路:

    let imageOptionsDictKeysPointer =  UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 1)
    imageOptionsDictKeysPointer.initialize(to: imageOptionsDictKeys)

出现错误访问错误.

在阅读文档后,我正在尝试编译此代码:

        let imageOptionsDictKeys = [kCVPixelBufferPixelFormatTypeKey, kCVPixelBufferWidthKey,  kCVPixelBufferHeightKey, kCVPixelBufferOpenGLESCompatibilityKey]
        let imageOptionsDictKeysRawPointer = Unmanaged.passUnretained(imageOptionsDictKeys).toOpaque()
        let imageOptionsDictKeysPointer =  UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 1)
        imageOptionsDictKeysPointer.initialize(to: imageOptionsDictKeysRawPointer)

        let imageOptionsDictValues = [ cvPixelFormatType,  frameW, frameH, boolYES]
        let imageOptionsDictValuesRawPointer = Unmanaged.passUnretained(imageOptionsDictValues).toOpaque()
        let imageOptionsDictValuesPointer =  UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 1)
        imageOptionsDictValuesPointer.initialize(to: imageOptionsDictValuesRawPointer)

        let imageOptions = CFDictionaryCreate(kCFAllocatorDefault, imageOptionsDictKeysPointer, imageOptionsDictValuesPointer, 4, &keyCallbacks, &valueCallbacks)

但错误 通用参数'Instance'无法推断出现在Unmanaged.passUnretained(array).toOpaque()行中

我现在不知道如何以编程方式创建CFDictionary.

Answer 1

我刚刚解决了一个类似的问题，将数组转换为UnsafeMutablePointer< UnsafeMutablePointer<T>>您可以在这里找到的： Swift 3 UnsafeMutablePointer optimization for C type float**

要使用相同的方案转换 swift 数组，请UnsafeMuTablePointer按照此处的建议使用：http ://technology.meronapps.com/2016/09/27/swift-3-0-unsafe-world-2/