Windows平台控制屏幕亮屏、息屏、锁屏

/// <summary>
/// 包含控制屏幕关闭以及系统休眠相关的方法。
/// </summary>
public static class SystemSleep
{
    private static uint WM_SYSCOMMAND = 0x112; //系统消息
    private static int SC_MONITORPOWER = 0xF170; //关闭显示器的系统命令
    private static int MonitorPowerOff = 2; //2为PowerOff, 1为省电状态，-1为开机
    private static int MonitorPowerOn = -1; //2为PowerOff, 1为省电状态，-1为开机
    private static readonly IntPtr HWND_BROADCAST = new IntPtr(0xffff);//广播消息，所有顶级窗体都会接收

    [DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
    public static void CloseScreen()
    {
        SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, MonitorPowerOff);
    }

    public static void OpenScreen()
    {
        SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, MonitorPowerOn);
    }

    [DllImport("user32.dll")]
    public static extern void LockWorkStation();


    [DllImport("kernel32")]
    private static extern ExecutionState SetThreadExecutionState(ExecutionState esFlags);
    [Flags]
    private enum ExecutionState : uint
    {
        /// <summary>
        /// Forces the system to be in the working state by resetting the system idle timer.
        /// </summary>
        SystemRequired = 0x01,

        /// <summary>
        /// Forces the display to be on by resetting the display idle timer.
        /// </summary>
        DisplayRequired = 0x02,

        /// <summary>
        /// This value is not supported. If <see cref="UserPresent"/> is combined with other esFlags values, the call will fail and none of the specified states will be set.
        /// </summary>
        [Obsolete("This value is not supported.")]
        UserPresent = 0x04,

        /// <summary>
        /// Enables away mode. This value must be specified with <see cref="Continuous"/>.
        /// <para />
        /// Away mode should be used only by media-recording and media-distribution applications that must perform critical background processing on desktop computers while the computer appears to be sleeping.
        /// </summary>
        AwaymodeRequired = 0x40,

        /// <summary>
        /// Informs the system that the state being set should remain in effect until the next call that uses <see cref="Continuous"/> and one of the other state flags is cleared.
        /// </summary>
        Continuous = 0x80000000,
    }
    /// <summary>
    /// 设置此线程此时开始一直将处于运行状态，此时计算机不应该进入睡眠状态。
    /// 此线程退出后，设置将失效。
    /// 如果需要恢复，请调用 <see cref="RestoreForCurrentThread"/> 方法。
    /// </summary>
    /// <param name="keepDisplayOn">
    /// 表示是否应该同时保持屏幕不关闭。
    /// 对于游戏、视频和演示相关的任务需要保持屏幕不关闭；而对于后台服务、下载和监控等任务则不需要。
    /// </param>
    public static void PreventForCurrentThread(bool keepDisplayOn = true)
    {
        SetThreadExecutionState(keepDisplayOn
            ? ExecutionState.Continuous | ExecutionState.SystemRequired | ExecutionState.DisplayRequired
            : ExecutionState.Continuous | ExecutionState.SystemRequired);
    }

    /// <summary>
    /// 恢复此线程的运行状态，操作系统现在可以正常进入睡眠状态和关闭屏幕。
    /// </summary>
    public static void RestoreForCurrentThread()
    {
        SetThreadExecutionState(ExecutionState.Continuous);
    }

    /// <summary>
    /// 重置系统睡眠或者关闭屏幕的计时器，这样系统睡眠或者屏幕能够继续持续工作设定的超时时间。
    /// </summary>
    /// <param name="keepDisplayOn">
    /// 表示是否应该同时保持屏幕不关闭。
    /// 对于游戏、视频和演示相关的任务需要保持屏幕不关闭；而对于后台服务、下载和监控等任务则不需要。
    /// </param>
    public static void ResetIdle(bool keepDisplayOn = true)
    {
        SetThreadExecutionState(keepDisplayOn
            ? ExecutionState.SystemRequired | ExecutionState.DisplayRequired
            : ExecutionState.SystemRequired);
    }
}

CloseScreen() 息屏
OpenScreen() 锁屏
PreventForCurrentThread() 使计算机不进入休眠
RestoreForCurrentThread() 恢复计算机为正常的休眠设置