如何将UnsafeMutablePointer <Void>转换为UInt8？

Question

问题很简单,但不知怎的,我不知道怎么做:

如何将UnsafeMutablePointer转换为UInt8？

我尝试像这样转换它:

UInt8(theUnsafeMutablePointerVar)

但它给了我以下错误:找不到类型为"UInt8"的初始值设定项,它接受类型为"UnsafeMutablePointer"的参数列表

Answer 1

您必须首先将指针转换为正确的类型(指向UInt8),然后您可以访问它指向的内存:

let u8 = UnsafePointer<UInt8>(theUnsafeMutablePointerVar).memory

在Swift 3中,来自C的void指针被导入Swift as UnsafeMutableRawPointer,并且可以读取指向的数据

let u8 = theUnsafeMutablePointerVar.load(as: UInt8.self)