xcode - 在 Swift 3 中将 NSData 转换为 NSString？

Question

我有一个返回某些系统值的函数。它在 Swift 2.2 中运行良好，我刚刚升级到 Xcode 8 和 Swift 3，现在失败了。

func ioPlatExpertDevString(_ property: String) -> String {
    // Start tapping in to the IO Service
    let ioPlatformExpertDevice:io_service_t? = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("IOPlatformExpertDevice"))

    var sAnswer = "Not Found"
    let cfAnswer:AnyObject! = IORegistryEntryCreateCFProperty(ioPlatformExpertDevice!, "\(property)" as CFString!, kCFAllocatorDefault, 0).takeRetainedValue()
    if (cfAnswer != nil) {
        let nsAnswer = (cfAnswer as! NSString)
        sAnswer = nsAnswer.uppercased
    }

    // Close the IO Service
    IOObjectRelease(ioPlatformExpertDevice!)

    return sAnswer
}

之前，我使用“CFData”而不是“AnyObject”。它构建得很好，但在运行时，我收到以下错误:

Could not cast value of type '__NSCFData' (0x7fff7b833ec0) to 'NSString' (0x7fff7ac32038).

Answer 1

替换

let nsAnswer = (cfAnswer as! NSString) 

至

let nsAnswer = NSString(data: cfAnswer as! Data, encoding: String.Encoding.utf8.rawValue)