swift - sysctlbyname 在 swift 1.2 中失败

Question

我让这段代码在 swift 1.1 中运行不确定如何修复它

var deviceModelIdentifier: String {
    var size : UInt = 0 // Swift 1.2: var size : Int = 0 (as Ben Stahl noticed in his answer)
    //sysctlbyname(_: UnsafePointer<Int8>, _: UnsafeMutablePointer<Void>, _: UnsafeMutablePointer<Int>, _: UnsafeMutablePointer<Void>, _: Int)
    sysctlbyname("hw.machine", nil, &size, nil, 0)
    var machine = [CChar](count: Int(size), repeatedValue: 0)
    sysctlbyname("hw.machine", &machine, &size, nil, 0)
    return String.fromCString(machine)!
}

错误:无法使用类型为“(String, nil, inout UInt, nil, Int)”的参数列表调用“sysctlbyname” sysctlbyname("hw.machine", nil, &size, nil, 0) ^错误:无法使用类型为“(String, inout [(CChar)], inout UInt, nil, Int)”的参数列表调用“sysctlbyname” sysctlbyname("hw.machine", &machine, &size, nil, 0)

感谢任何帮助

Answer 1

解决方案在您代码的注释中:Size 现在是 Int 而不是 1.2 中的 Uint，因此编译:

var deviceModelIdentifier: String {
    var size : Int = 0
    sysctlbyname("hw.machine", nil, &size, nil, 0)
    var machine = [CChar](count: size, repeatedValue: 0)
    sysctlbyname("hw.machine", &machine, &size, nil, 0)
    return String.fromCString(machine)!
}

(如果愿意，您也可以编写 var size : size_t = 0)

当您遍历不安全指针样板时，错误消息提示:

note: expected an argument list of type '(UnsafePointer< Int8 >, UnsafeMutablePointer< Void >, UnsafeMutablePointer<Int>, UnsafeMutablePointer< Void >, Int)'