C# 读取和设置大小写切换键状态

C# 读取和设置大小写切换键状态可以通过程序查看或者设置当前键盘上的Capslock健的状态是否打开

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace RobvanderWoude
{
	public class CapsLock
	{
		[DllImport( "user32.dll" )]
		static extern void keybd_event( byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo );
		const int KEYEVENTF_EXTENDEDKEY = 0x1;
		const int KEYEVENTF_KEYUP = 0x2;
		public static int Main( string[] args )
		{
			try
			{
				bool capsLock;
				bool newState = false;
				bool setState = false;
				bool setVerbose = false;
				bool verbose = true;
				if ( args.Length > 2 )
				{
					return WriteError( "Invalid command line argument(s)." );
				}
				else
				{
					foreach ( string arg in args )
					{
						switch ( arg.ToUpper( ) )
						{
							case "/?":
							case "-H":
							case "/HELP":
							case "-HELP":
							case "--HELP":
								return WriteError( string.Empty );
							case "/Q":
							case "-Q":
							case "/QUIET":
							case "-QUIET":
							case "--QUIET":
								if ( setVerbose )
								{
									return WriteError( "Duplicate switch not allowed." );
								}
								setVerbose = true;
								verbose = false;
								break;
							case "/V":
							case "-V":
							case "/VERBOSE":
							case "-VERBOSE":
							case "--VERBOSE":
								if ( setVerbose )
								{
									return WriteError( "Duplicate switch not allowed." );
								}
								setVerbose = true;
								verbose = true;
								break;
							case "0":
							case "OFF":
								if ( setState )
								{
									return WriteError( "Duplicate argument not allowed." );
								}
								setState = true;
								newState = false;
								break;
							case "1":
							case "ON":
								if ( setState )
								{
									return WriteError( "Duplicate argument not allowed." );
								}
								setState = true;
								newState = true;
								break;
							default:
								return WriteError( "Invalid command line argument " + arg );
						}
					}
				}
				if ( Control.IsKeyLocked( Keys.CapsLock ) )
				{
					capsLock = true;
					if ( setState && !newState )
					{
						keybd_event( 0x14, 0x45, KEYEVENTF_EXTENDEDKEY, (UIntPtr) 0 );
						keybd_event( 0x14, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, (UIntPtr) 0 );
					}
				}
				else
				{
					capsLock = false;
					if ( setState && newState )
					{
						keybd_event( 0x14, 0x45, KEYEVENTF_EXTENDEDKEY, (UIntPtr) 1 );
						keybd_event( 0x14, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, (UIntPtr) 1 );
					}
				}
				capsLock = Control.IsKeyLocked( Keys.CapsLock );
				if ( verbose )
				{
					Console.Write( "CapsLock = " );
					Console.ForegroundColor = ConsoleColor.White;
					Console.WriteLine( ( capsLock ? "ON" : "OFF" ) );
					Console.ResetColor( );
				}
				return ( capsLock ? 2 : 0 );
			}
			catch ( Exception e )
			{
				return WriteError( e );
			}
		}
		public static int WriteError( Exception e )
		{
			return WriteError( e == null ? null : e.Message );
		}
		public static int WriteError( string errorMessage )
		{
			/*
			CapsLock,  Version 1.01
			Read or set CapsLock key state
			Usage:  CAPSLOCK  [ 0 | 1 | ON | OFF ]  [ /Quiet | /Verbose ]
			Where:  0 or OFF   sets CapsLock off
					1 or ON    sets CapsLock on
			        /Quiet     won't display anything on screen
			        /Verbose   displays the (new) CapsLock key state on screen (default)
			Notes:  An 'errorlevel' 0 is returned if CapsLock is off, 2 if
					CapsLock is on, or 1 in case of (command line) errors.
			Written by Rob van der Woude
			http://www.robvanderwoude.com
			*/
			if ( string.IsNullOrEmpty( errorMessage ) == false )
			{
				Console.Error.WriteLine( );
				Console.ForegroundColor = ConsoleColor.Red;
				Console.Error.Write( "ERROR:  " );
				Console.ForegroundColor = ConsoleColor.White;
				Console.Error.WriteLine( errorMessage );
				Console.ResetColor( );
			}
			Console.Error.WriteLine( );
			Console.Error.WriteLine( "CapsLock,  Version 1.01" );
			Console.Error.WriteLine( "Read or set CapsLock key state" );
			Console.Error.WriteLine( );
			Console.Error.Write( "Usage:  " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.WriteLine( "CAPSLOCK  [ 0 | 1 | ON | OFF ]  [ /Quiet | /Verbose ]" );
			Console.ResetColor( );
			Console.Error.WriteLine( );
			Console.Error.Write( "Where:  " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "0" );
			Console.ResetColor( );
			Console.Error.Write( " or " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "OFF" );
			Console.ResetColor( );
			Console.Error.WriteLine( "   set CapsLock off" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "        1" );
			Console.ResetColor( );
			Console.Error.Write( " or " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "ON" );
			Console.ResetColor( );
			Console.Error.WriteLine( "    set CapsLock on" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "        /Q" );
			Console.ResetColor( );
			Console.Error.WriteLine( "uiet     won't display anything on screen" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "        /V" );
			Console.ResetColor( );
			Console.Error.WriteLine( "erbose   displays the (new) CapsLock key state on screen (default)" );
			Console.Error.WriteLine( );
			Console.Error.WriteLine( "Notes:  An \"errorlevel\" 0 is returned if CapsLock is off, 2 if" );
			Console.Error.WriteLine( "        CapsLock is on, or 1 in case of (command line) errors." );
			Console.Error.WriteLine( );
			Console.Error.WriteLine( "Written by Rob van der Woude" );
			Console.Error.WriteLine( "http://www.robvanderwoude.com" );
			return 1;
		}
	}
}