keyboard.cs

功能：基于windows mobile 的地图查看器。使用vs2005开发

using System;
using System.Runtime.InteropServices;

namespace PInvokeLibrary
{
	/// <summary>
	/// Summary description for Keyboard.
	/// </summary>
	public class Keyboard
	{
		private enum CheckMethod
		{
			kOS,
			kRegistry
		}

		private static bool IsKeyboard(CheckMethod method)
		{
			if (method == CheckMethod.kRegistry)
			{
				uint dwordResult;
				UIntPtr hkey = UIntPtr.Zero;

				try
				{
					int result = Registry.RegOpenKeyEx(Registry.HKCU, "SOFTWARE\\Microsoft\\Shell", 0, Registry.KeyAccess.None, ref hkey);
					if (Registry.ERROR_SUCCESS != result)
						return false;

					byte[] bytes = null;
					uint length = 0;
					Registry.KeyType keyType = Registry.KeyType.None;
                    
					result = Registry.RegQueryValueEx(hkey, "HasKeyboard", IntPtr.Zero, ref keyType,
						null, ref length);

					if (Registry.ERROR_SUCCESS != result)
						return false;

					bytes = new byte[Marshal.SizeOf(typeof(uint))];
					length = (uint)bytes.Length;
					keyType = Registry.KeyType.None;
                    
					result = Registry.RegQueryValueEx(hkey, "HasKeyboard", IntPtr.Zero, ref keyType,
						bytes, ref length);

					if (Registry.ERROR_SUCCESS != result)
						return false;

					dwordResult = BitConverter.ToUInt32(bytes, 0);

					return (dwordResult == 1);
				}
				finally
				{
					if (UIntPtr.Zero != hkey)
					{
						Registry.RegCloseKey(hkey);
					}
				}
			}
			else
			{
				uint flags = KBDI_KEYBOARD_ENABLED | KBDI_KEYBOARD_PRESENT;
				return ((GetKeyboardStatus() & flags) == flags);
			}
		}

		/// <summary>
		/// Indicates whether or not the system has keyboard hardware.
		/// </summary>
		public const uint KBDI_KEYBOARD_PRESENT = 0x0001;

		/// <summary>
		/// Indicates whether or not the keyboard hardware is enabled.
		/// </summary>
		public const uint KBDI_KEYBOARD_ENABLED = 0x0002;

		/// <summary>
		/// Indicates whether or not the keyboard hardware has ENTER and ESC keys.
		/// </summary>
		public const uint KBDI_KEYBOARD_ENTER_ESC = 0x0004;

		/// <summary>
		/// Indicates whether or not the keyboard hardware has alphanumeric keys.
		/// </summary>
		public const uint KBDI_KEYBOARD_ALPHA_NUM = 0x0008;

		/// <summary>
		/// This function returns the status of the hardware keyboard.
		/// </summary>
		/// <returns>This function returns a bit mask indicating whether or
		/// not a keyboard is present and what its capabilities are.</returns>
		[DllImport("coredll.dll")]
		public static extern uint GetKeyboardStatus();

		/// <summary>
		/// Run a test of the Registry class.
		/// </summary>
		/// <param name="showLine">Delegate called to show debug information</param>
		public static void TestProc(MainTest.DisplayLineDelegate showLine)
		{
			showLine("Checking registry...");
			if (IsKeyboard(CheckMethod.kRegistry))
				showLine("Keyboard detected");
			else
				showLine("No keyboard detected");

			showLine("Checking OS...");
			if (IsKeyboard(CheckMethod.kOS))
				showLine("Keyboard detected");
			else
				showLine("No keyboard detected");
		}
	}
}