Xml comments.

Interop.Windows/Dde/DdeSettings.cs

@@ -7,23 +7,39 @@
 	using Ecng.Common;
 	using Ecng.Serialization;
 
+	/// <summary>
+	/// Represents the settings for DDE (Dynamic Data Exchange) communication.
+	/// </summary>
 	[DisplayName("DDE settings")]
 	public class DdeSettings : Cloneable<DdeSettings>, IPersistable
 	{
+		/// <summary>
+		/// Initializes a new instance of the <see cref="DdeSettings"/> class with default values.
+		/// </summary>
 		public DdeSettings()
 		{
 			Server = "EXCEL";
 			Topic = "[Book1.xlsx]Sheet1";
 		}
 
+		/// <summary>
+		/// Gets or sets the DDE server name.
+		/// </summary>
 		[Display(Name = "Server", Description = "DDE server name.", Order = 0)]
 		public string Server { get; set; }
 
+		/// <summary>
+		/// Gets or sets the DDE topic name (for example, "[Book1.xlsx]Sheet1").
+		/// </summary>
 		[Display(Name = "Topic", Description = "Topic name (like [Book1.xlsx].Sheet1).", Order = 1)]
 		public string Topic { get; set; }
 
 		private int _columnOffset;
 
+		/// <summary>
+		/// Gets or sets the column offset from the left top corner.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">Thrown when a negative value is assigned.</exception>
 		[Display(Name = "Column offset", Description = "Column offset from left top corner.", Order = 2)]
 		public int ColumnOffset
 		{
@@ -39,6 +55,10 @@ public int ColumnOffset
 
 		private int _rowOffset;
 
+		/// <summary>
+		/// Gets or sets the row offset from the left top corner.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">Thrown when a negative value is assigned.</exception>
 		[Display(Name = "Row offset", Description = "Row offset from left top corner.", Order = 2)]
 		public int RowOffset
 		{
@@ -52,19 +72,34 @@ public int RowOffset
 			}
 		}
 
+		/// <summary>
+		/// Gets or sets a value indicating whether header names should be displayed.
+		/// </summary>
 		[Display(Name = "Headers", Description = "Show headers name.", Order = 2)]
 		public bool ShowHeaders { get; set; }
 
+		/// <summary>
+		/// Applies the settings from the specified <see cref="DdeSettings"/> instance.
+		/// </summary>
+		/// <param name="clone">The instance containing the new settings.</param>
 		public void Apply(DdeSettings clone)
 		{
 			PersistableHelper.Apply(this, clone);
 		}
 
+		/// <summary>
+		/// Creates a deep copy of the current <see cref="DdeSettings"/> instance.
+		/// </summary>
+		/// <returns>A new instance that is a deep copy of this instance.</returns>
 		public override DdeSettings Clone()
 		{
 			return PersistableHelper.Clone(this);
 		}
 
+		/// <summary>
+		/// Loads the settings from the provided <see cref="SettingsStorage"/>.
+		/// </summary>
+		/// <param name="storage">The storage from which to load the settings.</param>
 		public void Load(SettingsStorage storage)
 		{
 			Server = storage.GetValue<string>(nameof(Server));
@@ -74,6 +109,10 @@ public void Load(SettingsStorage storage)
 			ShowHeaders = storage.GetValue<bool>(nameof(ShowHeaders));
 		}
 
+		/// <summary>
+		/// Saves the current settings to the provided <see cref="SettingsStorage"/>.
+		/// </summary>
+		/// <param name="storage">The storage to which the settings will be saved.</param>
 		public void Save(SettingsStorage storage)
 		{
 			storage

Interop.Windows/Dde/XlsDdeClient.cs

@@ -7,20 +7,36 @@
 
 	using NDde.Client;
 
+	/// <summary>
+	/// A client for interacting with Excel via Dynamic Data Exchange (DDE), providing methods to start, stop, and send data.
+	/// </summary>
 	public class XlsDdeClient(DdeSettings settings) : Disposable
 	{
 		private DdeClient _client;
 
+		/// <summary>
+		/// Gets a value indicating whether the DDE client is currently started and connected.
+		/// </summary>
 		public bool IsStarted => _client != null;
 
+		/// <summary>
+		/// Gets the settings used to configure the DDE client.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">Thrown when the settings provided during construction are null.</exception>
 		public DdeSettings Settings { get; } = settings ?? throw new ArgumentNullException(nameof(settings));
 
+		/// <summary>
+		/// Starts the DDE client and establishes a connection to the specified server and topic.
+		/// </summary>
 		public void Start()
 		{
 			_client = new DdeClient(Settings.Server, Settings.Topic);
 			_client.Connect();
 		}
 
+		/// <summary>
+		/// Stops the DDE client and disconnects from the server if currently connected.
+		/// </summary>
 		public void Stop()
 		{
 			if (_client.IsConnected)
@@ -29,6 +45,12 @@ public void Stop()
 			_client = null;
 		}
 
+		/// <summary>
+		/// Sends a block of data to Excel via DDE using the specified row and column offsets.
+		/// </summary>
+		/// <param name="rows">A list of rows, where each row is a list of cell values to send.</param>
+		/// <exception cref="ArgumentNullException">Thrown when <paramref name="rows"/> is null.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="rows"/> is empty.</exception>
 		public void Poke(IList<IList<object>> rows)
 		{
 			if (rows is null)
@@ -48,6 +70,9 @@ public void Poke(IList<IList<object>> rows)
 				XlsDdeSerializer.Serialize(rows), 0x0090 | 0x4000, (int)TimeSpan.FromSeconds(10).TotalMilliseconds);
 		}
 
+		/// <summary>
+		/// Releases managed resources by stopping the DDE client if it is started.
+		/// </summary>
 		protected override void DisposeManaged()
 		{
 			if (IsStarted)

Interop.Windows/Dde/XlsDdeSerializer.cs

@@ -7,6 +7,9 @@
 
 	using Ecng.Common;
 
+	/// <summary>
+	/// Provides methods for serializing and deserializing data to and from a format compatible with Excel DDE.
+	/// </summary>
 	static class XlsDdeSerializer
 	{
 		private enum DataTypes : short
@@ -54,6 +57,12 @@ private static DataTypes GetXlsType(object cell)
 			throw new ArgumentException($"Unknown cell value type '{cell.GetType()}'.", nameof(cell));
 		}
 
+		/// <summary>
+		/// Serializes a table of data into a byte array compatible with Excel DDE.
+		/// </summary>
+		/// <param name="rows">A list of rows, where each row is a list of cell values to serialize.</param>
+		/// <returns>A byte array representing the serialized data.</returns>
+		/// <exception cref="ArgumentOutOfRangeException">Thrown when an unsupported cell type is encountered.</exception>
 		public static byte[] Serialize(IList<IList<object>> rows)
 		{
 			var stream = new MemoryStream();
@@ -101,6 +110,12 @@ public static byte[] Serialize(IList<IList<object>> rows)
 			return stream.ToArray();
 		}
 
+		/// <summary>
+		/// Deserializes a byte array from Excel DDE format into a table of data.
+		/// </summary>
+		/// <param name="data">The byte array containing the serialized DDE data.</param>
+		/// <returns>A list of rows, where each row is a list of cell values.</returns>
+		/// <exception cref="ArgumentNullException">Thrown when <paramref name="data"/> is null.</exception>
 		public static IList<IList<object>> Deserialize(byte[] data)
 		{
 			if (data is null)

Interop.Windows/Dde/XlsDdeServer.cs

@@ -9,19 +9,34 @@ namespace Ecng.Interop.Dde
 
 	using NDde.Server;
 
+	/// <summary>
+	/// Provides a DDE server for Excel that handles poke requests and advises clients of updated data.
+	/// </summary>
 	[CLSCompliant(false)]
 	public class XlsDdeServer(string service, Action<string, IList<IList<object>>> poke, Action<Exception> error) : DdeServer(service)
 	{
+		/// <summary>
+		/// Private helper class that dispatches events on dedicated threads.
+		/// </summary>
 		private class EventDispatcher(Action<Exception> errorHandler) : Disposable
 		{
 			private readonly Action<Exception> _errorHandler = errorHandler ?? throw new ArgumentNullException(nameof(errorHandler));
 			private readonly SynchronizedDictionary<string, BlockingQueue<Action>> _events = [];
 
+			/// <summary>
+			/// Adds an event to be executed.
+			/// </summary>
+			/// <param name="evt">The event action to add.</param>
 			public void Add(Action evt)
 			{
 				Add(evt, string.Empty);
 			}
 
+			/// <summary>
+			/// Adds an event to be executed with a synchronization token.
+			/// </summary>
+			/// <param name="evt">The event action to add.</param>
+			/// <param name="syncToken">The synchronization token to group events.</param>
 			public virtual void Add(Action evt, string syncToken)
 			{
 				if (evt is null)
@@ -63,6 +78,9 @@ private static BlockingQueue<Action> CreateNewThreadQueuePair(string syncToken)
 				return queue;
 			}
 
+			/// <summary>
+			/// Disposes the managed resources by closing all event queues.
+			/// </summary>
 			protected override void DisposeManaged()
 			{
 				_events.SyncDo(d => d.ForEach(p => p.Value.Close()));
@@ -76,6 +94,9 @@ protected override void DisposeManaged()
 		private readonly Action<string, IList<IList<object>>> _poke = poke ?? throw new ArgumentNullException(nameof(poke));
 		private readonly Action<Exception> _error = error ?? throw new ArgumentNullException(nameof(error));
 
+		/// <summary>
+		/// Starts the DDE server and initializes the timer to advise clients.
+		/// </summary>
 		public void Start()
 		{
 			Exception error = null;
@@ -125,6 +146,14 @@ public void Start()
 			.Interval(TimeSpan.FromSeconds(1));
 		}
 
+		/// <summary>
+		/// Handles poke requests from DDE conversations.
+		/// </summary>
+		/// <param name="conversation">The DDE conversation instance.</param>
+		/// <param name="item">The item name requested.</param>
+		/// <param name="data">The data payload in byte array format.</param>
+		/// <param name="format">The format of the data received.</param>
+		/// <returns>A <see cref="PokeResult"/> indicating that the poke has been processed.</returns>
 		protected override PokeResult OnPoke(DdeConversation conversation, string item, byte[] data, int format)
 		{
 			_dispather.Add(() =>
@@ -136,6 +165,10 @@ protected override PokeResult OnPoke(DdeConversation conversation, string item,
 			return PokeResult.Processed;
 		}
 
+		/// <summary>
+		/// Releases the unmanaged resources and, optionally, the managed resources.
+		/// </summary>
+		/// <param name="disposing">True to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
 		protected override void Dispose(bool disposing)
 		{
 			_dispather.Dispose();

Interop.Windows/WinApi.cs

@@ -5,11 +5,20 @@
 
 	using Microsoft.Win32;
 
-	///<summary>
-	///</summary>
+	/// <summary>
+	/// Provides Windows API utility methods.
+	/// </summary>
 	[CLSCompliant(false)]
 	public static class WinApi
 	{
+		/// <summary>
+		/// Retrieves the screen boundaries (left, top, width, height) for the screen that contains the specified window handle.
+		/// </summary>
+		/// <param name="hwnd">The handle of the window.</param>
+		/// <param name="left">Output parameter that returns the left coordinate of the screen.</param>
+		/// <param name="top">Output parameter that returns the top coordinate of the screen.</param>
+		/// <param name="width">Output parameter that returns the width of the screen.</param>
+		/// <param name="height">Output parameter that returns the height of the screen.</param>
 		public static void GetScreenParams(IntPtr hwnd, out int left, out int top, out int width, out int height)
 		{
 			var activeScreen = Screen.FromHandle(hwnd);
@@ -25,6 +34,13 @@ public static void GetScreenParams(IntPtr hwnd, out int left, out int top, out i
 
 		private static RegistryKey BaseKey => Registry.CurrentUser;
 
+		/// <summary>
+		/// Updates the auto-run registry entry for a given application.
+		/// </summary>
+		/// <param name="appName">The name of the application.</param>
+		/// <param name="path">The full path to the application executable.</param>
+		/// <param name="enabled">True to enable auto-run; false to disable it.</param>
+		/// <exception cref="InvalidOperationException">Thrown when the autorun registry key cannot be found.</exception>
 		public static void UpdateAutoRun(string appName, string path, bool enabled)
 		{
 			using var key = BaseKey.OpenSubKey(_path, true) ?? throw new InvalidOperationException($"autorun not found ({_path})");

Interop.Windows/WindowsGrandAccess.cs

@@ -11,9 +11,13 @@
 using Ecng.Common;
 
 // https://stackoverflow.com/a/30687230/8029915
+
+/// <summary>
+/// Provides methods to modify access rights for the Windows window station and desktop.
+/// </summary>
 public static class WindowsGrandAccess
 {
-	private class Token(WindowsGrandAccess.GenericSecurity wsSecurity, WindowsGrandAccess.GenericSecurity dsSecurity, int? oldWindowStationMaskm, int? oldDesktopMask) : Disposable
+	private class Token(GenericSecurity wsSecurity, WindowsGrandAccess.GenericSecurity dsSecurity, int? oldWindowStationMaskm, int? oldDesktopMask) : Disposable
 	{
 		private readonly GenericSecurity _wsSecurity = wsSecurity ?? throw new ArgumentNullException(nameof(wsSecurity));
 		private readonly GenericSecurity _dsSecurity = dsSecurity ?? throw new ArgumentNullException(nameof(dsSecurity));
@@ -35,6 +39,13 @@ protected override void DisposeManaged()
 	private const int _desktopRightsAllAccess = 0x000f01ff;
 	private const int _windowStationAllAccess = 0x000f037f;
 
+	/// <summary>
+	/// Grants full access rights to the current process window station and thread desktop for the specified user.
+	/// </summary>
+	/// <param name="username">The user account to which access rights are to be granted.</param>
+	/// <returns>
+	/// An <see cref="IDisposable"/> token that, when disposed, restores the original access rights.
+	/// </returns>
 	public static IDisposable GrantAccessToWindowStationAndDesktop(string username)
 	{
 		var wsHandle = new NoopSafeHandle(PInvoke.GetProcessWindowStation());

Interop.Windows/WindowsThreadingHelper.cs

@@ -5,8 +5,17 @@
 
 	using Ecng.Common;
 
+	/// <summary>
+	/// Provides helper methods to run code on threads with specific apartment states.
+	/// </summary>
 	public static class WindowsThreadingHelper
 	{
+		/// <summary>
+		/// Sets the apartment state of the specified thread to single-threaded apartment (STA).
+		/// </summary>
+		/// <param name="thread">The thread to set the apartment state for.</param>
+		/// <returns>The same thread with the updated apartment state.</returns>
+		/// <exception cref="ArgumentNullException">Thrown when the thread is null.</exception>
 		public static Thread STA(this Thread thread)
 		{
 			if (thread is null)
@@ -16,6 +25,12 @@ public static Thread STA(this Thread thread)
 			return thread;
 		}
 
+		/// <summary>
+		/// Sets the apartment state of the specified thread to multi-threaded apartment (MTA).
+		/// </summary>
+		/// <param name="thread">The thread to set the apartment state for.</param>
+		/// <returns>The same thread with the updated apartment state.</returns>
+		/// <exception cref="ArgumentNullException">Thrown when the thread is null.</exception>
 		public static Thread MTA(this Thread thread)
 		{
 			if (thread is null)
@@ -25,6 +40,11 @@ public static Thread MTA(this Thread thread)
 			return thread;
 		}
 
+		/// <summary>
+		/// Invokes the specified action on a new STA (single-threaded apartment) thread.
+		/// </summary>
+		/// <param name="action">The action to invoke.</param>
+		/// <exception cref="ArgumentNullException">Thrown when the action is null.</exception>
 		public static void InvokeAsSTA(this Action action)
 		{
 			if (action is null)
@@ -38,6 +58,15 @@ public static void InvokeAsSTA(this Action action)
 		}
 
 		// http://stackoverflow.com/questions/518701/clipboard-gettext-returns-null-empty-string
+
+		/// <summary>
+		/// Invokes the specified function on a new STA (single-threaded apartment) thread and returns a result.
+		/// </summary>
+		/// <typeparam name="T">The type of the return value.</typeparam>
+		/// <param name="func">The function to invoke.</param>
+		/// <returns>The result returned by the function.</returns>
+		/// <exception cref="ArgumentNullException">Thrown when the function is null.</exception>
+		/// <exception cref="Exception">Throws any exception that occurs during the function execution.</exception>
 		public static T InvokeAsSTA<T>(this Func<T> func)
 		{
 			if (func is null)