如何在Swift 3中访问CFDictionary? [英] How to access CFDictionary in Swift 3?

问题描述

我需要从CFDictionary实例读取和写入一些数据(以读取和更新照片中的EXIF数据).为了我的一生，我无法弄清楚如何在Swift 3中做到这一点.我想要的呼叫的签名是:

I need to read and write some data from CFDictionary instances (to read and update EXIF data in photos). For the life of me, I cannot figure out how to do this in Swift 3. The signature for the call I want is:

func CFDictionaryGetValue(CFDictionary!, UnsafeRawPointer!)

如何将密钥(字符串)转换为UnsafeRawPointer，以便可以将其传递给此调用?

How the heck do I convert my key (a string) to an UnsafeRawPointer so I can pass it to this call?

推荐答案

如果您不必处理期望CFDictionary的其他Core Foundation函数，则可以通过转换为Swift本机Dictionary来简化它:

If you don't have to deal with other Core Foundation functions expecting an CFDictionary, you can simplify it by converting to Swift native Dictionary:

if let dict = cfDict as? [String: AnyObject] {
    print(dict["key"])
}

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