Detect current Hyper-V state; async operations; F1 info message

HyperVSwitch/Extensions.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace HyperVSwitch
+{
+	internal static class Extensions
+	{
+		/// <summary>
+		/// Waits asynchronously for the process to exit.
+		/// </summary>
+		/// <param name="process">The process to wait for cancellation.</param>
+		/// <param name="cancellationToken">A cancellation token. If invoked, the task will return
+		///   immediately as canceled.</param>
+		/// <returns>A Task representing waiting for the process to end.</returns>
+		public static Task WaitForExitAsync(this Process process, CancellationToken cancellationToken = default(CancellationToken))
+		{
+			var tcs = new TaskCompletionSource<object>();
+			process.EnableRaisingEvents = true;
+			process.Exited += (sender, args) => tcs.TrySetResult(null);
+			if (cancellationToken != default(CancellationToken))
+			{
+				cancellationToken.Register(tcs.SetCanceled);
+			}
+			return tcs.Task;
+		}
+	}
+}

HyperVSwitch/HyperVSwitch.csproj

@@ -51,6 +51,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Extensions.cs" />
     <Compile Include="MainForm.cs">
       <SubType>Form</SubType>
     </Compile>

HyperVSwitch/MainForm.cs

@@ -3,6 +3,7 @@
 using System.Drawing;
 using System.IO;
 using System.Linq;
+using System.Threading.Tasks;
 using System.Windows.Forms;
 
 namespace HyperVSwitch
@@ -23,9 +24,24 @@ public MainForm()
 		{
 			InitializeComponent();
 
-			isHyperVActive = GetHyperVStatus();
+			statusLabel.Text = "Detecting current state…\nThis may take a few seconds.";
+			statusLabel.ForeColor = Color.Gray;
+			actionButton.Visible = false;
+			infoLabel.Text = "© 2016 Yves Goergen, GNU GPL v3";
+		}
+
+		#endregion Constructors
+
+		#region Window event handlers
+
+		private async void MainForm_Load(object sender, EventArgs args)
+		{
+			isHyperVActive = await GetHyperVStatus();
 			isHyperVRunning = GetHyperVRunning();
 
+			actionButton.Visible = true;
+			actionButton.Focus();
+
 			if (isHyperVActive == true)
 			{
 				statusLabel.Text = "Hyper-V is ACTIVE.";
@@ -53,59 +69,83 @@ public MainForm()
 			else
 			{
 				statusLabel.Text = "The current state of Hyper-V is UNKNOWN. The Hyper-V role may not be installed on this computer.";
+				statusLabel.ForeColor = SystemColors.WindowText;
 				actionButton.Text = "No action available";
 				actionButton.Enabled = false;
 			}
-			infoLabel.Text = "© 2016 Yves Goergen, GNU GPL v3";
 		}
 
-		#endregion Constructors
-
-		#region Window event handlers
-
 		private void MainForm_KeyDown(object sender, KeyEventArgs args)
 		{
 			if (args.KeyCode == Keys.Escape && args.Modifiers == 0)
 			{
 				Application.Exit();
 			}
+			if (args.KeyCode == Keys.F1 && args.Modifiers == 0)
+			{
+				string message =
+					"Hyper-V Switch allows you to enable or disable permanent virtualisation with Hyper-V without uninstalling it so that you can use Hyper-V and other virtualisation solutions like VMware or VirtualBox easily. This setting is stored in the boot configuration so that the computer must be restarted to apply the new setting.\n\n" +
+					"For more information please click on the link to open the website.\n\n" +
+					"Available keyboard shortcuts:\n\n" +
+					"Escape: Close program\n" +
+					"Shift+Click: Change state but skip restart (you need to restart manually)";
+				MessageBox.Show(message, "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
+			}
 		}
 
 		#endregion Window event handlers
 
 		#region Control event handlers
 
-		private void ActionButton_Click(object sender, EventArgs args)
+		private async void ActionButton_Click(object sender, EventArgs args)
 		{
-			if (!justRestart)
+			bool shiftKeyPressed = ModifierKeys == Keys.Shift;
+			actionButton.Enabled = false;
+			try
 			{
-				if (isHyperVActive == true)
+				if (!justRestart)
 				{
-					if (!SetHyperVStatus(false))
+					if (isHyperVActive == true)
 					{
-						MessageBox.Show("Deactivating Hyper-V failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
-						return;
+						if (!await SetHyperVStatus(false))
+						{
+							MessageBox.Show("Deactivating Hyper-V failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+							return;
+						}
 					}
-				}
-				else if (isHyperVActive == false)
-				{
-					if (!SetHyperVStatus(true))
+					else if (isHyperVActive == false)
+					{
+						if (!await SetHyperVStatus(true))
+						{
+							MessageBox.Show("Activating Hyper-V failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+							return;
+						}
+					}
+					else
 					{
-						MessageBox.Show("Activating Hyper-V failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
-						return;
+						return;   // Should not happen
 					}
 				}
-				else
+
+				if (!shiftKeyPressed)
 				{
-					return;   // Should not happen
+					if (!SafeNativeMethods.ExitWindowsEx(
+						ExitWindows.Reboot,
+						ShutdownReason.MajorOperatingSystem | ShutdownReason.MinorReconfig | ShutdownReason.FlagPlanned))
+					{
+						//int error = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
+						//string errorMessage = new System.ComponentModel.Win32Exception(error).Message;
+						//MessageBox.Show($"Restarting the computer failed. {errorMessage} (Error {error}) Trying another method…", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+
+						// ExitWindowsEx fails on Windows 10.
+						// Use the system command, there's no feedback from it.
+						Process.Start("shutdown.exe", "-r -t 0");
+					}
 				}
 			}
-
-			if (!SafeNativeMethods.ExitWindowsEx(
-				ExitWindows.RestartApps,
-				ShutdownReason.MajorOperatingSystem | ShutdownReason.MinorReconfig | ShutdownReason.FlagPlanned))
+			finally
 			{
-				MessageBox.Show("Restarting the computer failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				actionButton.Enabled = true;
 			}
 
 			// System is restarted. Prevent further actions
@@ -121,7 +161,7 @@ private void InfoLabel_LinkClicked(object sender, LinkLabelLinkClickedEventArgs
 
 		#region Hyper-V support methods
 
-		private bool? GetHyperVStatus()
+		private async Task<bool?> GetHyperVStatus()
 		{
 			var startInfo = new ProcessStartInfo
 			{
@@ -133,6 +173,7 @@ private void InfoLabel_LinkClicked(object sender, LinkLabelLinkClickedEventArgs
 			};
 			using (var process = Process.Start(startInfo))
 			{
+				await process.WaitForExitAsync();
 				while (!process.StandardOutput.EndOfStream)
 				{
 					string line = process.StandardOutput.ReadLine();
@@ -145,7 +186,7 @@ private void InfoLabel_LinkClicked(object sender, LinkLabelLinkClickedEventArgs
 			return null;
 		}
 
-		private bool SetHyperVStatus(bool active)
+		private async Task<bool> SetHyperVStatus(bool active)
 		{
 			var startInfo = new ProcessStartInfo
 			{
@@ -156,15 +197,14 @@ private bool SetHyperVStatus(bool active)
 			};
 			using (var process = Process.Start(startInfo))
 			{
-				process.WaitForExit();
+				await process.WaitForExitAsync();
 				return process.ExitCode == 0;
 			}
 		}
 
 		private bool? GetHyperVRunning()
 		{
-			// TODO
-			return null;
+			return !SafeNativeMethods.IsProcessorFeaturePresent(ProcessorFeature.PF_VIRT_FIRMWARE_ENABLED);
 		}
 
 		#endregion Hyper-V support methods

HyperVSwitch/SafeNativeMethods.cs

@@ -9,6 +9,10 @@ public static class SafeNativeMethods
 		[DllImport("user32.dll", SetLastError = true)]
 		[return: MarshalAs(UnmanagedType.Bool)]
 		public static extern bool ExitWindowsEx(ExitWindows uFlags, ShutdownReason dwReason);
+
+		[DllImport("kernel32.dll")]
+		[return: MarshalAs(UnmanagedType.Bool)]
+		public static extern bool IsProcessorFeaturePresent(ProcessorFeature processorFeature);
 	}
 
 	[Flags]
@@ -67,4 +71,9 @@ public enum ShutdownReason : uint
 		FlagUserDefined = 0x40000000,
 		FlagPlanned = 0x80000000
 	}
+
+	public enum ProcessorFeature
+	{
+		PF_VIRT_FIRMWARE_ENABLED = 21
+	}
 }