C#，SystemEvents.PowerModeChanged事件在睡眠或恢复时未引发

Question

我有一个简单的应用程序，用于检测笔记本电脑的睡眠/恢复事件：

using Microsoft.Win32;
using System;
namespace ConsoleApp2
{
internal class Program
{
static void Main(string[] args)
{
SystemEvents.PowerModeChanged +=
new PowerModeChangedEventHandler(SystemEvents_PowerModeChanged);
Console.ReadLine();
}
static void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
Console.WriteLine(e.Mode);
}
}
}

当我插入/拔下电源线时，我可以在控制台上看到消息StatusChange，但如果我按下睡眠按钮并稍后恢复笔记本电脑，则控制台上不会打印任何内容。

由于某些原因，睡眠/恢复事件无法访问应用程序。你能告诉我怎么修吗？

Answer 1

这可以捕获睡眠，恢复事件。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp3
{
internal class Program
{
static void Main(string[] args)
{
IntPtr registrationHandle = new IntPtr();
DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS recipient = new DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS();
recipient.Callback = new DeviceNotifyCallbackRoutine(DeviceNotifyCallback);
recipient.Context = IntPtr.Zero;
IntPtr pRecipient = Marshal.AllocHGlobal(Marshal.SizeOf(recipient));
Marshal.StructureToPtr(recipient, pRecipient, false);
uint result = PowerRegisterSuspendResumeNotification(DEVICE_NOTIFY_CALLBACK, ref recipient, ref registrationHandle);
if (result != 0)
Console.WriteLine("Error registering for power notifications: " + Marshal.GetLastWin32Error());
else
Console.WriteLine("Successfully Registered for power notifications!");
while (true) { }
}
private static int DeviceNotifyCallback(IntPtr context, int type, IntPtr setting)
{
Console.WriteLine($"Device notify callback called: context: {context},type: {type}, setings: {setting}");
switch (type)
{
case PBT_APMPOWERSTATUSCHANGE:
Console.WriteLine("tPower status has changed.");
break;
case PBT_APMRESUMEAUTOMATIC:
Console.WriteLine("tOperation is resuming automatically from a low-power state.This message is sent every time the system resumes.");
break;
case PBT_APMRESUMESUSPEND:
Console.WriteLine("tOperation is resuming from a low-power state.This message is sent after PBT_APMRESUMEAUTOMATIC if the resume is triggered by user input, such as pressing a key.");
break;
case PBT_APMSUSPEND:
Console.WriteLine("tSystem is suspending operation.");
break;
case PBT_POWERSETTINGCHANGE:
Console.WriteLine("tA power setting change event has been received. ");
break;
default:
Console.WriteLine("unknown");
break;
}
// do something here
return 0;
}
[DllImport("Powrprof.dll", SetLastError = true)]
static extern uint PowerRegisterSuspendResumeNotification(uint flags, ref DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS receipient, ref IntPtr registrationHandle);

private const int WM_POWERBROADCAST = 536; // (0x218)
private const int PBT_APMPOWERSTATUSCHANGE = 10; // (0xA) - Power status has changed.
private const int PBT_APMRESUMEAUTOMATIC = 18; // (0x12) - Operation is resuming automatically from a low-power state.This message is sent every time the system resumes.
private const int PBT_APMRESUMESUSPEND = 7; // (0x7) - Operation is resuming from a low-power state.This message is sent after PBT_APMRESUMEAUTOMATIC if the resume is triggered by user input, such as pressing a key.
private const int PBT_APMSUSPEND = 4; // (0x4) - System is suspending operation.
private const int PBT_POWERSETTINGCHANGE = 32787; // (0x8013) - A power setting change event has been received.
private const int DEVICE_NOTIFY_CALLBACK = 2;
/// <summary>
/// OS callback delegate definition
/// </summary>
/// <param name="context">The context for the callback</param>
/// <param name="type">The type of the callback...for power notifcation it's a PBT_ message</param>
/// <param name="setting">A structure related to the notification, depends on type parameter</param>
/// <returns></returns>
delegate int DeviceNotifyCallbackRoutine(IntPtr context, int type, IntPtr setting);
/// <summary>
/// A callback definition
/// </summary>
[StructLayout(LayoutKind.Sequential)]
struct DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS
{
public DeviceNotifyCallbackRoutine Callback;
public IntPtr Context;
}
}
}