检测 Mac 是否有背光键盘

Question

\xe2\x80\x99s 很容易检测 Mac 是否有发光键盘ioreg在命令行中，

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ioreg -c IOResources -d 3 | grep '"KeyboardBacklight" =' | sed 's/^.*= //g'\n

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但我怎样才能以编程方式得到这个IOKit使用最新的 Swift 以编程方式获取这个布尔属性呢？我\xe2\x80\x99m 寻找一些示例代码。

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Answer 1

我通过一些尝试和错误发现了以下内容：

• 从 IO 注册表获取“IOResources”节点。
• 从该节点获取“KeyboardBacklight”属性。
• （有条件）将属性值转换为布尔值。

我已经在 MacBook Air（带键盘背光）和 iMac（不带键盘背光）上进行了测试，在两种情况下都产生了正确的结果。

import Foundation
import IOKit

func keyboardHasBacklight() -> Bool {
    let port: mach_port_t
    if #available(macOS 12.0, *) {
        port = kIOMainPortDefault // New name as of macOS 12
    } else {
        port = kIOMasterPortDefault // Old name up to macOS 11
    }
    let service = IOServiceGetMatchingService(port, IOServiceMatching(kIOResourcesClass))
    guard service != IO_OBJECT_NULL else {
        // Could not read IO registry node. You have to decide whether
        // to treat this as a fatal error or not.
        return false
    }
    guard let cfProp = IORegistryEntryCreateCFProperty(service, "KeyboardBacklight" as CFString,
                                                       kCFAllocatorDefault, 0)?.takeRetainedValue(),
          let hasBacklight = cfProp as? Bool
    else {
        // "KeyboardBacklight" property not present, or not a boolean.
        // This happens on Macs without keyboard backlight.
        return false
    }
    // Successfully read boolean "KeyboardBacklight" property:
    return hasBacklight
}