Added nullability to PowrProf

PInvoke/PowrProf/PowerBase.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Runtime.InteropServices;
-using Vanara.InteropServices;
-
 namespace Vanara.PInvoke;
 
 /// <summary>Functions, structures and constants from powrprof.dll.</summary>

PInvoke/PowrProf/PowerSetting.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Runtime.InteropServices;
-using Vanara.InteropServices;
-
 namespace Vanara.PInvoke;
 
 public static partial class PowrProf

PInvoke/PowrProf/PowrProf.cs

@@ -1,8 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.Runtime.InteropServices;
-using System.Text;
-using Vanara.InteropServices;
 
 namespace Vanara.PInvoke;
 
@@ -3656,21 +3652,20 @@ public static partial class PowrProf
 			return f(g1.HasValue ? (IntPtr)(void*)&ptrs[0] : IntPtr.Zero, g2.HasValue ? (IntPtr)(void*)&ptrs[1] : IntPtr.Zero, g3.HasValue ? (IntPtr)(void*)&ptrs[2] : IntPtr.Zero);
 	}
 
-	private static SafeHGlobalHandle PwrReadMem(PwrReadMemFunc f, Guid? g1, Guid? g2, Guid? g3)
+	private static SafeHGlobalHandle PwrReadMem(PwrReadMemFunc f, Guid? g1, Guid? g2, Guid? g3) => 
+		PwrGuidTsl(g1, g2, g3, (p1, p2, p3) =>
 		{
-		return PwrGuidTsl(g1, g2, g3, (p1, p2, p3) => {
 			var sz = 0U;
 			var err = f(HKEY.NULL, p1, p2, p3, IntPtr.Zero, ref sz);
 			if (err.Failed)
 			{
-				if (err == Win32Error.ERROR_FILE_NOT_FOUND) return null;
+				if (err == Win32Error.ERROR_FILE_NOT_FOUND) return SafeHGlobalHandle.Null;
-				if (err != Win32Error.ERROR_MORE_DATA) throw err.GetException();
+				if (err != Win32Error.ERROR_MORE_DATA) throw err.GetException()!;
 			}
 			var p = new SafeHGlobalHandle((int)sz);
 			f(HKEY.NULL, p1, p2, p3, (IntPtr)p, ref sz).ThrowIfFailed();
 			return p;
 		});
-	}
 
 	/// <summary>Contains parameters used when registering for a power notification.</summary>
 	// https://docs.microsoft.com/en-us/windows/desktop/api/powrprof/ns-powrprof-device_notify_subscribe_parameters typedef struct

UnitTests/PInvoke/PowrProf/PowrProf.cs

@@ -1,12 +1,6 @@
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Runtime.InteropServices;
-using System.Text;
 using System.Threading;
-using System.Threading.Tasks;
-using Vanara.Extensions;
 using static Vanara.PInvoke.PowrProf;
 
 namespace Vanara.PInvoke.Tests;
@@ -19,7 +13,7 @@ public class PowrProfTests
 	{
 		Assert.That(EnumPwrSchemes(p), Is.True);
 
-		bool p(uint uiIndex, uint dwName, string sName, uint dwDesc, string sDesc, in POWER_POLICY pp, IntPtr lParam)
+		static bool p(uint uiIndex, uint dwName, string sName, uint dwDesc, string sDesc, in POWER_POLICY pp, IntPtr lParam)
 		{
 			TestContext.WriteLine($"Idx:{uiIndex}; Name:{sName}; Desc:{sDesc}");
 			return true;
@@ -45,13 +39,13 @@ public class PowrProfTests
 			}
 		}
 
-		void WriteName(Guid? sch, Guid? grp, Guid? setting) { TestContext.WriteLine($"{PowerReadFriendlyName(sch, grp, setting)} : {PowerReadDescription(sch, grp, setting)} : {setting}"); }
+		static void WriteName(Guid? sch, Guid? grp, Guid? setting) => TestContext.WriteLine($"{PowerReadFriendlyName(sch, grp, setting)} : {PowerReadDescription(sch, grp, setting)} : {setting}");
 	}
 
 	[Test]
 	public void PowerReadSettingAttributesTest()
 	{
-		var attr = PowerReadSettingAttributes(default(Guid), default(Guid));
+		var attr = PowerReadSettingAttributes(default, default);
 		TestContext.WriteLine($"DefGuid={attr}");
 		attr = PowerReadSettingAttributes(GUID_SYSTEM_BUTTON_SUBGROUP, default);
 		TestContext.WriteLine($"GUID_SYSTEM_BUTTON_SUBGROUP={attr}");
@@ -61,7 +55,7 @@ public class PowrProfTests
 	public void PowerSettingRegisterNotificationTest()
 	{
 		uint timeOut = 0;
-		var evt = new AutoResetEvent(false);
+		AutoResetEvent evt = new(false);
 		Assert.That(PowerSettingRegisterNotification(GUID_VIDEO_POWERDOWN_TIMEOUT, DEVICE_NOTIFY.DEVICE_NOTIFY_CALLBACK, new DEVICE_NOTIFY_SUBSCRIBE_PARAMETERS { Callback = PowerSettingFunc }, out var powerNotification), ResultIs.Successful);
 		evt.WaitOne(1000);
 		Assert.That(PowerSettingUnregisterNotification(powerNotification), ResultIs.Successful);