无法将 'CFString' 类型的值转换为预期的参数类型 'UnsafePointer<Void>'(也称为"不安全指针<()>")

Question

当我定义行时，我遇到了一个构建错误

 let runFont : CTFontRef = CFDictionaryGetValue(CTRunGetAttributes(run), kCTFontAttributeName)

错误是：无法将"CFString"类型的值转换为预期的参数类型"UnsafePointer"（又名"UnsafoPointer<（）>'）

Answer 1

尝试

let runFont = unsafeBitCast(CFDictionaryGetValue(CTRunGetAttributes(run), unsafeBitCast(kCTFontAttributeName, UnsafePointer<Void>.self)), CTFontRef.self)

Answer 2

Swift 3版本的@vadian答案：

let runFont = unsafeBitCast(CFDictionaryGetValue(CTRunGetAttributes(run), unsafeBitCast(kCTFontAttributeName, to: UnsafeRawPointer.self)), to: CTFont.self)