PowerStatus.cs

using System.Runtime.InteropServices;

namespace BatteryDown;

internal static class PowerStatus
{
    public static bool IsOnBattery
    {
        get
        {
            if (!GetSystemPowerStatus(out var status))
            {
                throw new InvalidOperationException("无法读取当前电源状态。");
            }

            return status.ACLineStatus == 0;
        }
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetSystemPowerStatus(out SystemPowerStatus systemPowerStatus);

    [StructLayout(LayoutKind.Sequential)]
    private struct SystemPowerStatus
    {
        public byte ACLineStatus;
        public byte BatteryFlag;
        public byte BatteryLifePercent;
        public byte SystemStatusFlag;
        public uint BatteryLifeTime;
        public uint BatteryFullLifeTime;
    }
}