如何使用电源管理功能（PowerEnuimerate）获得电源设置

问题描述

我需要我的应用程序读取一些信息，例如系统在关闭显示器，进入睡眠或进入休眠状态之前将等待的时间。据我所知，我需要使用电源管理功能（）特别是，看起来我需要使用PowerEnumerate方法（）。

I need my application to read things like the amount of time the system will wait before shutting off the display, or going to sleep, or going into hibernate. As far as I can tell, I need to use the Power Management Functions (http://msdn.microsoft.com/en-us/library/aa373163%28v=vs.85%29.aspx) In particular, it looks like I need to use the PowerEnumerate method (http://msdn.microsoft.com/en-us/library/aa372730%28v=vs.85%29.aspx).

我真的对如何执行此操作感到困惑。首先，我在C＃中执行此操作，代码看起来是C ++。其次，C ++代码似乎并没有真正告诉您如何具体读取我想要的不同超时时间。

I'm really confused about how to do this. First, I'm doing this in C#, and the code looks to be C++. Second, the C++ code seems to not really tell you how to specifically read the different time outs I want.

注意，我是Windows编程和C＃的新手。我的大部分经验是Java和Android。

Note, I'm new to windows programming and C#. Most of my experience has been in Java and Android.

谢谢

推荐答案

我找到了一个上使用了VB中的 PowerEnumerate 函数。

I found an example on MSDN for using the PowerEnumerate function in VB.

我已将示例转换为C＃，并将友好名称添加到循环中每个视频设置的输出中。您可以将 GUID_VIDEO_SUBGROUP 更改为其他子组之一以查看其他设置。

I have converted the example to C#, and added the Friendly Name to the output of each Video setting in the loop. You can change the GUID_VIDEO_SUBGROUP to one of the other subgroups to see the other settings.

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;

namespace TestProject
{
    class PowerEnumerator
    {
        private static Guid NO_SUBGROUP_GUID = new Guid("fea3413e-7e05-4911-9a71-700331f1c294");
        private static Guid GUID_DISK_SUBGROUP = new Guid("0012ee47-9041-4b5d-9b77-535fba8b1442");
        private static Guid GUID_SYSTEM_BUTTON_SUBGROUP = new Guid("4f971e89-eebd-4455-a8de-9e59040e7347");
        private static Guid GUID_PROCESSOR_SETTINGS_SUBGROUP = new Guid("54533251-82be-4824-96c1-47b60b740d00");
        private static Guid GUID_VIDEO_SUBGROUP = new Guid("7516b95f-f776-4464-8c53-06167f40cc99");
        private static Guid GUID_BATTERY_SUBGROUP = new Guid("e73a048d-bf27-4f12-9731-8b2076e8891f");
        private static Guid GUID_SLEEP_SUBGROUP = new Guid("238C9FA8-0AAD-41ED-83F4-97BE242C8F20");
        private static Guid GUID_PCIEXPRESS_SETTINGS_SUBGROUP = new Guid("501a4d13-42af-4429-9fd1-a8218c268e20");

        [DllImport("powrprof.dll")]
        static extern uint PowerEnumerate(
            IntPtr RootPowerKey,
            IntPtr SchemeGuid,
            ref Guid SubGroupOfPowerSetting,
            uint AccessFlags,
            uint Index,
            ref Guid Buffer,
            ref uint BufferSize);

        [DllImport("powrprof.dll")]
        static extern uint PowerGetActiveScheme(
            IntPtr UserRootPowerKey,
            ref IntPtr ActivePolicyGuid);

        [DllImport("powrprof.dll")]
        static extern uint PowerReadACValue(
            IntPtr RootPowerKey,
            IntPtr SchemeGuid,
            IntPtr SubGroupOfPowerSettingGuid,
            ref Guid PowerSettingGuid,
            ref int Type,
            ref IntPtr Buffer,
            ref uint BufferSize
            );

        [DllImport("powrprof.dll", CharSet = CharSet.Unicode)]
        static extern uint PowerReadFriendlyName(
            IntPtr RootPowerKey,
            IntPtr SchemeGuid,
            IntPtr SubGroupOfPowerSettingGuid,
            IntPtr PowerSettingGuid,
            StringBuilder Buffer,
            ref uint BufferSize
            );

        [DllImport("kernel32.dll")]
        static extern IntPtr LocalFree(
            IntPtr hMem
            );

        private const uint ERROR_MORE_DATA = 234;

        public static void GetCurrentPowerEnumerateVistaAPI()
        {
            IntPtr activeGuidPtr = IntPtr.Zero;
            try
            {
                uint res = PowerGetActiveScheme(IntPtr.Zero, ref activeGuidPtr);
                if (res != 0)
                    throw new Win32Exception();

                //Get Friendly Name
                uint buffSize = 0;
                StringBuilder buffer = new StringBuilder();
                Guid subGroupGuid = Guid.Empty;
                Guid powerSettingGuid = Guid.Empty;
                res = PowerReadFriendlyName(IntPtr.Zero, activeGuidPtr,
                    IntPtr.Zero, IntPtr.Zero, buffer, ref buffSize);

                if (res == ERROR_MORE_DATA)
                {
                    buffer.Capacity = (int)buffSize;
                    res = PowerReadFriendlyName(IntPtr.Zero, activeGuidPtr,
                        IntPtr.Zero, IntPtr.Zero, buffer, ref buffSize);
                }

                if (res != 0)
                    throw new Win32Exception();

                Console.WriteLine("ReadFriendlyName = " +
                    buffer.ToString());

                //Get the Power Settings
                Guid VideoSettingGuid = Guid.Empty;
                uint index = 0;
                uint BufferSize = Convert.ToUInt32(Marshal.SizeOf(typeof(Guid)));

                while (
                    PowerEnumerate(IntPtr.Zero, activeGuidPtr, ref GUID_VIDEO_SUBGROUP,
                    18, index, ref VideoSettingGuid, ref BufferSize) == 0)
                {
                    uint size = 4;
                    IntPtr temp = IntPtr.Zero;
                    int type = 0;
                    res = PowerReadACValue(IntPtr.Zero, activeGuidPtr, IntPtr.Zero,
                        ref VideoSettingGuid, ref type, ref temp, ref size);

                    IntPtr pSubGroup = Marshal.AllocHGlobal(Marshal.SizeOf(GUID_VIDEO_SUBGROUP));
                    Marshal.StructureToPtr(GUID_VIDEO_SUBGROUP, pSubGroup, false);
                    IntPtr pSetting = Marshal.AllocHGlobal(Marshal.SizeOf(VideoSettingGuid));
                    Marshal.StructureToPtr(VideoSettingGuid, pSetting, false);

                    uint builderSize = 200;
                    StringBuilder builder = new StringBuilder((int)builderSize);
                    res = PowerReadFriendlyName(IntPtr.Zero, activeGuidPtr,
                        pSubGroup, pSetting, builder, ref builderSize);
                    Console.WriteLine(builder.ToString() + " = " + temp.ToString());

                    index++;
                }
            }
            finally
            {
                if (activeGuidPtr != IntPtr.Zero)
                {
                    IntPtr res = LocalFree(activeGuidPtr);
                    if (res != IntPtr.Zero)
                        throw new Win32Exception();
                }
            }
        }
    }
}

此代码的输出结果：

这篇关于如何使用电源管理功能（PowerEnuimerate）获得电源设置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！