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

问题描述

这是我在早期版本的Swift中可用的代码:

Here was my workable code in the previous version of Swift:

 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中进行更改之后，我必须将键和值数组转换为UnsafeMutablePointer<UnsafeRawPointer?>才能创建CFDictionary.

After changes in the Swift 3.0 I have to convert my keys and values arrays into UnsafeMutablePointer<UnsafeRawPointer?> for creating CFDictionary.

这种方式:

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

给出了错误的访问错误.

gives an Bad Access error.

阅读文档后，我尝试编译此代码:

And after reading documentation I am trying to compile this code:

        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)

但是错误无法推断出通用参数实例" 出现在 Unmanaged.passUnretained( array ).toOpaque()

but error Generic parameter 'Instance' could not be inferred appears in the lines Unmanaged.passUnretained(array).toOpaque()

我现在不知道如何以编程方式创建CFDictionary.

I have no idea how to create CFDictionary programmatically now.

推荐答案

我刚刚解决了将数组转换为UnsafeMutablePointer< UnsafeMutablePointer<T>>的类似问题，您可以在这里找到:针对C型浮点数的Swift 3 UnsafeMutablePointer初始化**

I just solved a similar issue converting arrays to UnsafeMutablePointer< UnsafeMutablePointer<T>> which you can find here:Swift 3 UnsafeMutablePointer initialization for C type float**

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

To convert swift arrays using the same scheme, use UnsafeMuTablePointer as suggested here: http://technology.meronapps.com/2016/09/27/swift-3-0-unsafe-world-2/

这篇关于如何将数组转换为UnsafeMutablePointer< UnsafeRawPointer?雨燕3.0?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！