Source code for dropdownbox.cs

```
using System;
```
```
using System.Collections.Generic;
```
```
using System.Drawing;
```
```
using System.IO;
```
```
using System.Linq;
```
```
using System.Runtime.InteropServices;
```
```
using System.Text;
```
```
using System.Text.RegularExpressions;
```
```
using System.Windows.Forms;
```
```
 
```
```
 
```
```
namespace RobvanderWoude
```
```
{
```
```
	class DropDownBox
```
```
	{
```

		public static string progver = "1.17";

		public static bool returnindex0 = false;

		public static bool returnindex1 = false;

```
 
```
```
		[STAThread]
```
```
		static int Main( string[] args )
```
```
		{
```
```
			#region Initialize Variables
```
```
 
```
```
			const int defaultheight = 90;
```
```
			const int defaultwidth = 200;
```
```
 
```
```
			char delimiter = ';';
```

			List<string> namedargs = new List<string>( );

			List<string> unnamedargs = new List<string>( );

```
			string file = String.Empty;
```
```
			string list = String.Empty;
```
```
			string cancelcaption = "&Cancel";
```
```
			string okcaption = "&OK";
```

			string localizationstring = String.Empty;

```
			string prompt = String.Empty;
```
```
			string selectedText = String.Empty;
```

			string title = String.Format( "DropDownBox,  Version {0}", progver );

```
			bool delimiterset = false;
```
```
			bool heightset = false;
```
```
			bool iconset = false;
```
```
			bool indexset = false;
```
```
			bool localizedcaptionset = false;
```
```
			bool monospaced = false;
```
```
			bool skipfirstitem = false;
```
```
			bool sortlist = false;
```
```
			bool tablengthset = false;
```
```
			bool topmost = true;
```
```
			bool widthset = false;
```
```
			int height = defaultheight;
```
```
			int icon = 23;
```
```
			int selectedindex = 0;
```
```
			int tablength = 4;
```
```
			int width = defaultwidth;
```
```
 
```

			bool isredirected = Console.IsInputRedirected; // Requires .NET Framework 4.5

```
			bool listset = isredirected;
```

			int redirectnum = ( isredirected ? 1 : 0 );

			int arguments = args.Length + redirectnum;

```
 
```
```
			#endregion Initialize Variables
```
```
 
```
```
 
```
```
			#region Command Line Parsing
```
```
 
```
```
			if ( arguments == 0 )
```
```
			{
```
```
				return ShowHelp( );
```
```
			}
```
```
 
```
```
			if ( arguments > 13 )
```
```
			{
```

				return ShowHelp( "Too many command line arguments" );

```
			}
```
```
 
```

			// Split up named and unnamed arguments

```
			foreach ( string arg in args )
```
```
			{
```
```
				if ( arg == "/?" )
```
```
				{
```
```
					return ShowHelp( );
```
```
				}
```
```
				if ( arg[0] == '/' )
```
```
				{
```
```
					namedargs.Add( arg );
```
```
				}
```
```
				else
```
```
				{
```
```
					unnamedargs.Add( arg );
```
```
				}
```
```
			}
```
```
 
```

			// Read Standard Input if the list is redirected

```
			if ( isredirected )
```
```
			{
```
```
				try
```
```
				{
```

					string delim = delimiter.ToString( );

					list = string.Join( delim, Console.In.ReadToEnd( ).Split( "\n\r".ToCharArray( ), StringSplitOptions.RemoveEmptyEntries ) );

					// Trim list items, remove empty ones

					string pattern = "\\s*" + delim + "+\\s*";

					list = Regex.Replace( list, pattern, delim );

```
				}
```
```
				catch ( Exception e )
```
```
				{
```
```
					return ShowHelp( e.Message );
```
```
				}
```
```
			}
```
```
 
```

			// First, validate the named arguments

```
			#region Named Arguments
```
```
 
```
```
			foreach ( string arg in namedargs )
```
```
			{
```

				if ( arg.Length < 3 && arg.ToUpper( ) != "/K" && arg.ToUpper( ) != "/L" && arg.ToUpper( ) != "/S" )

```
				{
```

					return ShowHelp( "Invalid command line switch {0} or missing value", arg );

```
				}
```
```
				if ( arg.ToUpper( ) == "/K" )
```
```
				{
```
```
					if ( skipfirstitem )
```
```
					{
```

						return ShowHelp( "Duplicate command line switch /K" );

```
					}
```
```
					skipfirstitem = true;
```
```
				}
```
```
				else if ( arg.ToUpper( ) == "/L" )
```
```
				{
```
```
					if ( localizedcaptionset )
```
```
					{
```

						return ShowHelp( "Duplicate command line switch /L" );

```
					}
```
```
					localizedcaptionset = true;
```
```
				}
```
```
				else if ( arg.ToUpper( ) == "/S" )
```
```
				{
```
```
					if ( sortlist )
```
```
					{
```

						return ShowHelp( "Duplicate command line switch /S" );

```
					}
```
```
					sortlist = true;
```
```
				}
```
```
				else
```
```
				{
```

					switch ( arg.Substring( 0, 3 ).ToUpper( ) )

```
					{
```
```
						case "/C:":
```
```
							if ( iconset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /D" );

```
							}
```
```
							try
```
```
							{
```

								icon = Convert.ToInt32( arg.Substring( 3 ) );

```
							}
```
```
							catch ( Exception )
```
```
							{
```

								return ShowHelp( "Invalid icon index: {0}", arg.Substring( 3 ) );

```
							}
```
```
							iconset = true;
```
```
							break;
```
```
						case "/D:":
```
```
							if ( delimiterset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /D" );

```
							}
```

							string test = arg.Substring( 3 );

```
							if ( test.Length == 1 )
```
```
							{
```
```
								delimiter = test[0];
```
```
							}
```

							else if ( test.Length == 3 && ( ( test[0] == '"' && test[2] == '"' ) || ( test[0] == '\'' && test[2] == '\'' ) ) )

```
							{
```
```
								delimiter = test[1];
```
```
							}
```
```
							else
```
```
							{
```

								return ShowHelp( "Invalid delimiter specified \"{0}\"", arg );

```
							}
```
```
							break;
```
```
						case "/F:":
```
```
							if ( listset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /F" );

```
							}
```
```
							file = arg.Substring( 3 );
```

							if ( string.IsNullOrEmpty( file ) || !File.Exists( file ) )

```
							{
```

								return ShowHelp( "List file not found: \"{0}\"", file );

```
							}
```
```
							else
```
```
							{
```
```
								try
```
```
								{
```

									string delim = delimiter.ToString( );

									list = String.Join( delim, File.ReadLines( file ) );

```
									// Remove empty list items
```

									string pattern = delim + "{2,}";

									list = Regex.Replace( list, pattern, delim );

									pattern = "(^" + delim + "|" + delim + "$)";

									list = Regex.Replace( list, pattern, string.Empty );

```
								}
```
```
								catch ( Exception e )
```
```
								{
```
```
									return ShowHelp( e.Message );
```
```
								}
```
```
							}
```
```
							listset = true;
```
```
							break;
```
```
						case "/H:":
```
```
							if ( heightset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /H" );

```
							}
```
```
							try
```
```
							{
```

								height = Convert.ToInt32( arg.Substring( 3 ) );

								if ( height < defaultheight || height > Screen.PrimaryScreen.Bounds.Height )

```
								{
```

									return ShowHelp( "Height {0} outside allowed range of {1}..{2}", arg.Substring( 3 ), defaultheight.ToString( ), Screen.PrimaryScreen.Bounds.Height.ToString( ) );

```
								}
```
```
							}
```
```
							catch ( Exception e )
```
```
							{
```

								return ShowHelp( "Invalid height \"{0}\": {1}", arg.Substring( 3 ), e.Message );

```
							}
```
```
							heightset = true;
```
```
							break;
```
```
						case "/I:":
```
```
							if ( indexset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /I" );

```
							}
```
```
							try
```
```
							{
```

								selectedindex = Convert.ToInt32( arg.Substring( 3 ) );

```
							}
```
```
							catch ( Exception e )
```
```
							{
```

								return ShowHelp( "Invalid index value \"{0}\": {1}", arg, e.Message );

```
							}
```
```
							break;
```
```
						case "/L:":
```
```
							if ( localizedcaptionset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /L" );

```
							}
```
```
							localizedcaptionset = true;
```

							localizationstring = arg.Substring( 3 );

							string localizationpattern = "(;|^)(OK|Cancel)=[^\\\"';]+(;|$)";

							foreach ( string substring in localizationstring.Split( ";".ToCharArray( ), StringSplitOptions.RemoveEmptyEntries ) )

```
							{
```

								if ( !Regex.IsMatch( substring, localizationpattern, RegexOptions.IgnoreCase ) )

```
								{
```

									return ShowHelp( "Invalid value for /L switch: \"{1}\"", localizationstring );

```
								}
```
```
							}
```
```
							break;
```
```
						case "/MF":
```
```
							if ( monospaced )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /MF" );

```
							}
```
```
							monospaced = true;
```
```
							break;
```
```
						case "/NM":
```
```
							if ( !topmost )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /NM" );

```
							}
```
```
							topmost = false;
```
```
							break;
```
```
						case "/R0":
```
```
						case "/RO":
```

							if ( returnindex0 || returnindex1 )

```
							{
```

								return ShowHelp( "Duplicate command line switch /R0, /R1, /RI and/or /RO" );

```
							}
```
```
							returnindex0 = true;
```
```
							break;
```
```
						case "/R1":
```
```
						case "/RI":
```

							if ( returnindex0 || returnindex1 )

```
							{
```

								return ShowHelp( "Duplicate command line switch /R0, /R1, /RI and/or /RO" );

```
							}
```
```
							returnindex1 = true;
```
```
							break;
```
```
						case "/T:":
```
```
							if ( tablengthset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /T" );

```
							}
```
```
							try
```
```
							{
```

								tablength = Convert.ToInt32( arg.Substring( 3 ) );

								if ( tablength < 4 || tablength > 16 )

```
								{
```

									return ShowHelp( "Tab length {0} outside allowed range of 4..16", arg.Substring( 3 ) );

```
								}
```
```
							}
```
```
							catch ( Exception e )
```
```
							{
```

								return ShowHelp( "Invalid tab length \"{0}\": {1}", arg.Substring( 3 ), e.Message );

```
							}
```
```
							tablengthset = true;
```
```
							break;
```
```
						case "/W:":
```
```
							if ( widthset )
```
```
							{
```

								return ShowHelp( "Duplicate command line switch /W" );

```
							}
```
```
							try
```
```
							{
```

								width = Convert.ToInt32( arg.Substring( 3 ) );

								if ( width < defaultwidth || width > Screen.PrimaryScreen.Bounds.Width )

```
								{
```

									return ShowHelp( "Width {0} outside allowed range of {1}..{2}", arg.Substring( 3 ), defaultwidth.ToString( ), Screen.PrimaryScreen.Bounds.Width.ToString( ) );

```
								}
```
```
							}
```
```
							catch ( Exception e )
```
```
							{
```

								return ShowHelp( "Invalid width \"{0}\": {1}", arg.Substring( 3 ), e.Message );

```
							}
```
```
							widthset = true;
```
```
							break;
```
```
						default:
```

							return ShowHelp( "Invalid command line switch \"{0}\"", arg );

```
					}
```
```
				}
```
```
			}
```
```
 
```
```
			#endregion Named Arguments
```
```
 
```
```
 
```
```
			// Next, validate unnamed arguments
```
```
			#region Unnamed Arguments
```
```
 
```

			if ( listset ) // This check is the reason why named arguments had to be validated before unnamed ones: /F switch changes the meaning of unnamed arguments

```
			{
```
```
				switch ( unnamedargs.Count )
```
```
				{
```
```
					case 0:
```
```
						break;
```
```
					case 1:
```
```
						prompt = unnamedargs[0];
```
```
						break;
```
```
					case 2:
```
```
						prompt = unnamedargs[0];
```
```
						title = unnamedargs[1];
```
```
						break;
```
```
					case 3:
```

						return ShowHelp( "Invalid command line argument: {0}", unnamedargs[2] );

```
					default:
```
```
						unnamedargs.RemoveRange( 0, 2 );
```

						return ShowHelp( "Invalid command line arguments: {0}", String.Join( ", ", unnamedargs ) );

```
				}
```
```
			}
```
```
			else
```
```
			{
```
```
				switch ( unnamedargs.Count )
```
```
				{
```
```
					case 0:
```
```
						break;
```
```
					case 1:
```
```
						list = unnamedargs[0];
```
```
						listset = true;
```
```
						break;
```
```
					case 2:
```
```
						list = unnamedargs[0];
```
```
						prompt = unnamedargs[1];
```
```
						listset = true;
```
```
						break;
```
```
					case 3:
```
```
						list = unnamedargs[0];
```
```
						prompt = unnamedargs[1];
```
```
						title = unnamedargs[2];
```
```
						listset = true;
```
```
						break;
```
```
					case 4:
```

						return ShowHelp( "Invalid command line argument: {0}", unnamedargs[3] );

```
					default:
```
```
						unnamedargs.RemoveRange( 0, 3 );
```

						return ShowHelp( "Invalid command line arguments: {0}", String.Join( ", ", unnamedargs ) );

```
				}
```
```
			}
```
```
 
```
```
			#endregion Unnamed Arguments
```
```
 
```
```
 
```
```
			// List is mandatory
```
```
			if ( !listset )
```
```
			{
```

				return ShowHelp( "No list specified" );

```
			}
```
```
 
```
```
			// Validate selected index
```

			int listrange = list.Split( delimiter ).Length - 1;

			if ( selectedindex < 0 || selectedindex > listrange )

```
			{
```

				return ShowHelp( "Selected index ({0}) outside list range (0..{0})", selectedindex.ToString( ), listrange.ToString( ) );

```
			}
```
```
 
```
```
			#endregion Command Line Parsing
```
```
 
```
```
 
```
```
			#region Set Localized Captions
```
```
 
```
```
			if ( localizedcaptionset )
```
```
			{
```

				cancelcaption = Load( "user32.dll", 801, cancelcaption );

				okcaption = Load( "user32.dll", 800, okcaption );

```
 
```

				if ( !string.IsNullOrWhiteSpace( localizationstring ) )

```
				{
```

					string[] locstrings = localizationstring.Split( ";".ToCharArray( ) );

					foreach ( string locstring in locstrings )

```
					{
```

						string key = locstring.Substring( 0, locstring.IndexOf( '=' ) );

						string val = locstring.Substring( Math.Min( locstring.IndexOf( '=' ) + 1, locstring.Length - 1 ) );

						if ( !string.IsNullOrWhiteSpace( val ) )

```
						{
```
```
							switch ( key.ToUpper( ) )
```
```
							{
```
```
								case "OK":
```
```
									okcaption = val;
```
```
									break;
```
```
								case "CANCEL":
```
```
									cancelcaption = val;
```
```
									break;
```
```
								default:
```

									return ShowHelp( "Invalid localization key \"{0}\"", key );

```
							}
```
```
						}
```
```
					}
```
```
				}
```
```
			}
```
```
 
```
```
			#endregion Set Localized Captions
```
```
 
```
```
 
```
```
			#region Build Form
```
```
 
```

			// Inspired by code by Gorkem Gencay on StackOverflow.com:

			// http://stackoverflow.com/questions/97097/what-is-the-c-sharp-version-of-vb-nets-inputdialog#17546909

```
 
```
```
			Form dropdownForm = new Form( );
```

			Size size = new Size( width, height );

			dropdownForm.FormBorderStyle = FormBorderStyle.FixedDialog;

```
			dropdownForm.MaximizeBox = false;
```
```
			dropdownForm.MinimizeBox = false;
```

			dropdownForm.StartPosition = FormStartPosition.CenterParent;

```
			dropdownForm.ClientSize = size;
```
```
			dropdownForm.Text = title;
```

			dropdownForm.Icon = IconExtractor.Extract( "shell32.dll", icon, true );

```
 
```

			if ( !string.IsNullOrWhiteSpace( prompt ) )

```
			{
```
```
				Label labelPrompt = new Label( );
```

				labelPrompt.Size = new Size( size.Width - 20, 20 );

				labelPrompt.Location = new Point( 10, 10 );

```
				// Replace tabs with spaces
```

				if ( prompt.IndexOf( "\\t", StringComparison.Ordinal ) > -1 )

```
				{
```

					string tab = new string( ' ', tablength );

					// First split the prompt on newlines

					string[] prompt2 = prompt.Split( new string[] { "\\n" }, StringSplitOptions.None );

					for ( int i = 0; i < prompt2.Length; i++ )

```
					{
```

						if ( prompt2[i].IndexOf( "\\t", StringComparison.Ordinal ) > -1 )

```
						{
```

							// Slit each "sub-line" of the prompt on tabs

							string[] prompt3 = prompt2[i].Split( new string[] { "\\t" }, StringSplitOptions.None );

							// Each substring before a tab gets n spaces attached, and then is cut off at the highest possible length which is a multiple of n

							for ( int j = 0; j < prompt3.Length - 1; j++ )

```
							{
```
```
								prompt3[j] += tab;
```
```
								int length = prompt3[j].Length;
```
```
								length /= tablength;
```
```
								length *= tablength;
```

								prompt3[j] = prompt3[j].Substring( 0, length );

```
							}
```

							prompt2[i] = string.Join( "", prompt3 );

```
						}
```
```
					}
```

					prompt = string.Join( "\n", prompt2 );

```
				}
```

				labelPrompt.Text = prompt.Replace( "\\n", "\n" ).Replace( "\\r", "\r" );

```
				if ( !heightset )
```
```
				{
```

					// Add 20 to window height to allow space for prompt

					size = new Size( size.Width, size.Height + 20 );

```
					dropdownForm.ClientSize = size;
```
```
				}
```

				labelPrompt.Size = new Size( size.Width - 20, size.Height - 90 );

```
				if ( monospaced )
```
```
				{
```

					labelPrompt.Font = new Font( FontFamily.GenericMonospace, labelPrompt.Font.Size );

```
				}
```

				dropdownForm.Controls.Add( labelPrompt );

```
			}
```
```
 
```
```
			ComboBox combobox;
```
```
			combobox = new ComboBox( );
```

			combobox.Size = new Size( size.Width - 20, 25 );

			combobox.Location = new Point( 10, size.Height - 70 );

			combobox.AutoCompleteMode = AutoCompleteMode.Append;

			combobox.AutoCompleteSource = AutoCompleteSource.ListItems;

			combobox.DropDownStyle = ComboBoxStyle.DropDownList;

			dropdownForm.Controls.Add( combobox );

```
 
```
```
			Button okButton = new Button( );
```

			okButton.DialogResult = DialogResult.OK;

```
			okButton.Name = "okButton";
```
```
			okButton.Size = new Size( 80, 25 );
```
```
			okButton.Text = okcaption;
```

			okButton.Location = new Point( size.Width / 2 - 10 - 80, size.Height - 35 );

			dropdownForm.Controls.Add( okButton );

```
 
```
```
			Button cancelButton = new Button( );
```

			cancelButton.DialogResult = DialogResult.Cancel;

```
			cancelButton.Name = "cancelButton";
```

			cancelButton.Size = new Size( 80, 25 );

```
			cancelButton.Text = cancelcaption;
```

			cancelButton.Location = new Point( size.Width / 2 + 10, size.Height - 35 );

			dropdownForm.Controls.Add( cancelButton );

```
 
```

			dropdownForm.AcceptButton = okButton;  // OK on Enter

			dropdownForm.CancelButton = cancelButton; // Cancel on Esc

```
			dropdownForm.Activate( );
```
```
 
```
```
			#endregion Build Form
```
```
 
```
```
 
```
```
			#region Populate List
```
```
 
```
```
			// Populate the dropdown list
```

			List<string> listitems = list.Split( delimiter ).ToList<string>( );

```
			if ( skipfirstitem )
```
```
			{
```
```
				listitems.RemoveAt( 0 );
```
```
			}
```
```
			if ( sortlist )
```
```
			{
```
```
				listitems.Sort( );
```
```
			}
```
```
			foreach ( string item in listitems )
```
```
			{
```
```
				combobox.Items.Add( item );
```
```
			}
```
```
			// Preselect an item
```

			combobox.SelectedIndex = selectedindex;

```
 
```
```
			#endregion Populate List
```
```
 
```
```
 
```
```
			dropdownForm.TopMost = topmost;
```

			DialogResult result = dropdownForm.ShowDialog( );

```
			if ( result == DialogResult.OK )
```
```
			{
```

				selectedText = combobox.SelectedItem.ToString( );

```
				Console.WriteLine( selectedText );
```
```
				if ( returnindex0 )
```
```
				{
```

					// With /RO: return code equals selected index for "OK", or -1 for (command line) errors or "Cancel".

```
					return combobox.SelectedIndex;
```
```
				}
```
```
				else if ( returnindex1 )
```
```
				{
```

					// With /RI: return code equals selected index + 1 for "OK", or 0 for (command line) errors or "Cancel".

```
					return combobox.SelectedIndex + 1;
```
```
				}
```
```
				else
```
```
				{
```

					// Default: return code 0 for "OK", 1 for (command line) errors, 2 for "Cancel".

```
					return 0;
```
```
				}
```
```
			}
```
```
			else
```
```
			{
```
```
				// Cancelled
```
```
				if ( returnindex0 )
```
```
				{
```

					// With /RO: return code equals selected index for "OK", or -1 for (command line) errors or "Cancel".

```
					return -1;
```
```
				}
```
```
				else if ( returnindex1 )
```
```
				{
```

					// With /RI: return code equals selected index + 1 for "OK", or 0 for (command line) errors or "Cancel".

```
					return 0;
```
```
				}
```
```
				else
```
```
				{
```

					// Default: return code 0 for "OK", 1 for (command line) errors, 2 for "Cancel".

```
					return 2;
```
```
				}
```
```
			}
```
```
		}
```
```
 
```
```
 
```
```
		#region Error handling
```
```
 
```

		public static int ShowHelp( params string[] errmsg )

```
		{
```
```
			#region Help Text
```
```
 
```
```
			/*
```
```
			DropDownBox,  Version 1.15
```

			Batch tool to present a DropDown dialog and return the selected item

```
 
```

			Usage:    DROPDOWNBOX     "list"  [ "prompt"  [ "title" ] ]  [ options ]

```
 
```

			   or:    DROPDOWNBOX     /F:"listfile"  [ "prompt"  [ "title" ] ]  [ options ]

```
 
```

			   or:    listcommand  |  DROPDOWNBOX  [ "prompt"  [ "title" ] ]  [ options ]

```
 
```

			Where:    "list"          is the list of items to populate the dropdown control

			          "listcommand"   is a command whose standard output is used as a list

			                          of items to populate the dropdown control

			          "prompt"        is the optional text above the dropdown control

			                          (default: none)

			          "title"         is the window title

			                          (default: "DropDownBox,  Version 1.10")

```
 
```

			Options:  /C:index        use iCon at index from shell32.dll (default: 23)

			          /D:"delimiter"  sets the Delimiter character for "list"

			                          (default: semicolon)

			          /F:"listfile"   use list from text File (one list item per line)

			          /H:height       sets the Height of the input box

			                          (default: 90; minimum: 90; maximum: screen height)

			          /I:index        sets the zero based Index of the preselected item

			                          (default: 0)

			          /K              sKip first item of list (e.g. a header line)

			          /L[:"captions"] Localize or customize button captions

			                          (e.g. /L:"OK=Why Not?;Cancel=No Way!")

			          /MF             use Monospaced Font in prompt (default: proportional)

			          /NM             make dialog Non-Modal (default: Modal, i.e. on top)

			          /RI or /R1      Return code equals selected Index + 1, or 0 on

			                          (command line) errors or if "Cancel" was clicked

			                          (default: 0 on "OK", 1 on error, 2 on "Cancel")

			          /RO or /R0      Return code equals selected 0-based index, or -1 on

			                          (command line) errors or if "Cancel" was clicked

			                          (default: 0 on "OK", 1 on error, 2 on "Cancel")

			          /S              Sort list (default: unsorted)

			          /T:tablength    sets the number of spaces for Tabs in prompt

			                          (4..16; default: 4)

			          /W:width        sets the Width of the input box

			                          (default: 200; minimum: 200; maximum: screen width)

```
 
```

			Notes:    The selected item text is written to Standard Out if "OK" is clicked,

			          otherwise an empty string is returned.

			          Use either "list" or /F:"listfile" or "listcommand".

			          Linefeeds (\n), tabs (\t) and doublequotes (\") are allowed in the

			          prompt text (but not in the title); with tabs, /MF is recommended.

			          If specified without captions, switch /L forces localized button

			          captions (e.g. "Cancel" button caption is "Annuleren" on Dutch

			          systems); if only a single custom caption is specified, the other

			          one is localized (e.g. with /L:"OK=Gaan" on Dutch systems, "OK"

			          button caption is "Gaan", "Cancel" button caption is "Annuleren").

			          Return code 0 for "OK", 1 for (command line) errors, 2 for "Cancel".

			          With /RI return code equals selected index + 1, or 0 for "Cancel".

			          With /RO return code equals selected index or -1 for "Cancel".

			          Command line switches /RI and /RO are mutually exclusive.

```
 
```

			Credits:  On-the-fly form based on code by Gorkem Gencay on StackOverflow:

			          http://stackoverflow.com/questions/97097#17546909

			          Code to retrieve localized button captions by Martin Stoeckli:

			          http://martinstoeckli.ch/csharp/csharp.html#windows_text_resources

			          Code to extract icons from Shell32.dll by Thomas Levesque:

			          http://stackoverflow.com/questions/6873026

```
 
```
```
			Written by Rob van der Woude
```
```
			http://www.robvanderwoude.com
```
```
			*/
```
```
 
```
```
			#endregion Help Text
```
```
 
```
```
 
```
```
			#region Error Message
```
```
 
```
```
			if ( errmsg.Length > 0 )
```
```
			{
```

				List<string> errargs = new List<string>( errmsg );

```
				errargs.RemoveAt( 0 );
```
```
				Console.Error.WriteLine( );
```

				Console.ForegroundColor = ConsoleColor.Red;

```
				Console.Error.Write( "ERROR:\t" );
```

				Console.ForegroundColor = ConsoleColor.White;

				Console.Error.WriteLine( errmsg[0], errargs.ToArray( ) );

```
				Console.ResetColor( );
```
```
			}
```
```
 
```
```
			#endregion Error Message
```
```
 
```
```
 
```
```
			#region Show Help Text
```
```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```

			Console.Error.WriteLine( "DropDownBox,  Version {0}", progver );

```
 
```

			Console.Error.WriteLine( "Batch tool to present a DropDown dialog and return the selected item" );

```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```
```
			Console.Error.Write( "Usage:    " );
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.WriteLine( "DROPDOWNBOX     \"list\"  [ \"prompt\"  [ \"title\" ] ]  [ options ]" );

```
			Console.ResetColor( );
```
```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```
```
			Console.Error.Write( "   or:    " );
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.WriteLine( "DROPDOWNBOX     /F:\"listfile\"  [ \"prompt\"  [ \"title\" ] ]  [ options ]" );

```
			Console.ResetColor( );
```
```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```
```
			Console.Error.Write( "   or:    " );
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.WriteLine( "listcommand  |  DROPDOWNBOX  [ \"prompt\"  [ \"title\" ] ]  [ options ]" );

```
			Console.ResetColor( );
```
```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```
```
			Console.Error.Write( "Where:    " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "\"list\"" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "          is the list of items to populate the dropdown control" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          \"listcommand\"" );

```
			Console.ResetColor( );
```
```
			Console.Error.Write( "   is a " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "command" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( " whose standard output is used as a " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.WriteLine( "list" );
```
```
			Console.ResetColor( );
```
```
 
```

			Console.Error.WriteLine( "                          of items to populate the dropdown control" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          \"prompt\"" );

```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "        is the optional text above the dropdown control" );

```
 
```

			Console.Error.WriteLine( "                          (default: none)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          \"title\"" );

```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "         is the window title" );

```
 
```

			Console.Error.WriteLine( "                          (default: \"DropDownBox,  Version {0}\")", progver );

```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```
```
			Console.Error.Write( "Options:  " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/C:index" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( "        use i" );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "C" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( "on at " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "index" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " from shell32.dll (default: 23)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /D:\"delimiter\"" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "  sets the " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "D" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( "elimiter character for " );

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.WriteLine( "\"list\"" );

```
			Console.ResetColor( );
```
```
 
```

			Console.Error.WriteLine( "                          (default: semicolon)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /F:\"listfile\"" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "   use list from text " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "F" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "ile (one list item per line)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /H:height" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "       sets the " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "H" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "eight of the input box" );

```
 
```

			Console.Error.WriteLine( "                          (default: 90; minimum: 90; maximum: screen height)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /I:index" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "        sets the zero based " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "I" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "ndex of the preselected item" );

```
 
```

			Console.Error.WriteLine( "                          (default: 0)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /K" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "              s" );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "K" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "ip first item of list (e.g. a header line)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /L[:\"captions\"] L" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "ocalize or customize button " );

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.WriteLine( "captions" );

```
			Console.ResetColor( );
```
```
 
```

			Console.Error.Write( "                          (e.g. " );

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "/L:\"OK=Why Not?;Cancel=No Way!\"" );

```
			Console.ResetColor( );
```
```
			Console.Error.WriteLine( ")" );
```
```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /MF" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "             use " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "M" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( "onospaced " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "F" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( "ont in " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "prompt" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " (default: proportional)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /NM" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "             make dialog " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "N" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( "on-" );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "M" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "odal (default: modal, i.e. on top)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /RI" );

```
			Console.ResetColor( );
```
```
			Console.Error.Write( " or " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/R1      R" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( "eturn code equals selected " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "I" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "ndex + 1, or 0 on" );

```
 
```

			Console.Error.WriteLine( "                          (command line) errors or if \"Cancel\" was clicked" );

```
 
```

			Console.Error.WriteLine( "                          (default: 0 on \"OK\", 1 on error, 2 on \"Cancel\")" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /RO" );

```
			Console.ResetColor( );
```
```
			Console.Error.Write( " or " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/R0      R" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( "eturn code equals selected " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "0" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "-based index, or -1 on" );

```
 
```

			Console.Error.WriteLine( "                          (command line) errors or if \"Cancel\" was clicked" );

```
 
```

			Console.Error.WriteLine( "                          (default: 0 on \"OK\", 1 on error, 2 on \"Cancel\")" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /S              S" );

```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "ort list (default: unsorted)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /T:tablength" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "    sets the number of spaces for " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "T" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( "abs in " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.WriteLine( "prompt" );
```
```
			Console.ResetColor( );
```
```
 
```

			Console.Error.WriteLine( "                          (4..16; default: 4)" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          /W:width" );

```
			Console.ResetColor( );
```

			Console.Error.Write( "        sets the " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "W" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( "idth of the input box" );

```
 
```

			Console.Error.WriteLine( "                          (default: 200; minimum: 200; maximum: screen width)" );

```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```

			Console.Error.WriteLine( "Notes:    The selected item text is written to Standard Out if \"OK\" is clicked," );

```
 
```

			Console.Error.WriteLine( "          otherwise an empty string is returned." );

```
 
```

			Console.Error.Write( "          Use either " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "\"list\"" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( " or " );
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "/F:\"listfile\"" );

```
			Console.ResetColor( );
```
```
			Console.Error.Write( " or " );
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "\"listcommand\"" );

```
			Console.ResetColor( );
```
```
			Console.Error.WriteLine( "." );
```
```
 
```

			Console.Error.WriteLine( "          Linefeeds (\\n), tabs (\\t) and doublequotes (\\\") are allowed in the" );

```
 
```

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "          prompt" );

```
			Console.ResetColor( );
```

			Console.Error.Write( " text (but not in the " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "title" );
```
```
			Console.ResetColor( );
```

			Console.Error.Write( "); with tabs, " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/MF" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " is recommended." );

```
 
```

			Console.Error.Write( "          If specified without " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "captions" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( ", switch " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/L" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " forces localized button" );

```
 
```

			Console.Error.WriteLine( "          captions (e.g. \"Cancel\" button caption is \"Annuleren\" on Dutch" );

```
 
```

			Console.Error.WriteLine( "          systems); if only a single custom caption is specified, the other" );

```
 
```

			Console.Error.Write( "          one is localized (e.g. with " );

			Console.ForegroundColor = ConsoleColor.White;

			Console.Error.Write( "/L:\"OK=Gaan\"" );

```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " on Dutch systems, \"OK\"" );

```
 
```

			Console.Error.WriteLine( "          button caption is \"Gaan\", \"Cancel\" button caption is \"Annuleren\")." );

```
 
```

			Console.Error.WriteLine( "          Return code 0 for \"OK\", 1 for (command line) errors, 2 for \"Cancel\"." );

```
 
```

			Console.Error.Write( "          With " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/RI" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " return code equals selected index + 1, or 0 for \"Cancel\"." );

```
 
```

			Console.Error.Write( "          With " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/RO" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " return code equals selected index, or -1 for \"Cancel\"." );

```
 
```

			Console.Error.Write( "          Command line switches " );

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/RI" );
```
```
			Console.ResetColor( );
```
```
			Console.Error.Write( " and " );
```

			Console.ForegroundColor = ConsoleColor.White;

```
			Console.Error.Write( "/RO" );
```
```
			Console.ResetColor( );
```

			Console.Error.WriteLine( " are mutually exclusive." );

```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```

			Console.Error.WriteLine( "Credits:  On-the-fly form based on code by Gorkem Gencay on StackOverflow:" );

```
 
```

			Console.ForegroundColor = ConsoleColor.DarkGray;

			Console.Error.WriteLine( "          http://stackoverflow.com/questions/17546909" );

```
			Console.ResetColor( );
```
```
 
```

			Console.Error.WriteLine( "          Code to retrieve localized button captions by Martin Stoeckli:" );

```
 
```

			Console.ForegroundColor = ConsoleColor.DarkGray;

			Console.Error.WriteLine( "          http://martinstoeckli.ch/csharp/csharp.html#windows_text_resources" );

```
			Console.ResetColor( );
```
```
 
```

			Console.Error.WriteLine( "          Code to extract icons from Shell32.dll by Thomas Levesque:" );

```
 
```

			Console.ForegroundColor = ConsoleColor.DarkGray;

			Console.Error.WriteLine( "          http://stackoverflow.com/questions/6873026" );

```
			Console.ResetColor( );
```
```
 
```
```
			Console.Error.WriteLine( );
```
```
 
```

			Console.Error.WriteLine( "Written by Rob van der Woude" );

```
 
```

			Console.Error.WriteLine( "http://www.robvanderwoude.com" );

```
 
```
```
			#endregion Show Help Text
```
```
 
```
```
 
```
```
			if ( returnindex0 )
```
```
			{
```

				// With /RO: return code equals selected index for "OK", or -1 for (command line) errors or "Cancel".

```
				return -1;
```
```
			}
```
```
			else if ( returnindex1 )
```
```
			{
```

				// With /RI: return code equals selected index + 1 for "OK", or 0 for (command line) errors or "Cancel".

```
				return 0;
```
```
			}
```
```
			else
```
```
			{
```

				// Default: return code 0 for "OK", 1 for (command line) errors, 2 for "Cancel".

```
				return 1;
```
```
			}
```
```
		}
```
```
 
```
```
		#endregion Error handling
```
```
 
```
```
 
```
```
		#region Get Localized Captions
```
```
 
```

		// Code to retrieve localized captions by Martin Stoeckli

		// http://martinstoeckli.ch/csharp/csharp.html#windows_text_resources

```
 
```
```
		/// <summary>
```

		/// Searches for a text resource in a Windows library.

		/// Sometimes, using the existing Windows resources, you can make your code

		/// language independent and you don't have to care about translation problems.

```
		/// </summary>
```
```
		/// <example>
```

		///   btnCancel.Text = Load("user32.dll", 801, "Cancel");

		///   btnYes.Text = Load("user32.dll", 805, "Yes");

```
		/// </example>
```

		/// <param name="libraryName">Name of the windows library like "user32.dll"

```
		/// or "shell32.dll"</param>
```

		/// <param name="ident">Id of the string resource.</param>

		/// <param name="defaultText">Return this text, if the resource string could

```
		/// not be found.</param>
```

		/// <returns>Requested string if the resource was found,

		/// otherwise the <paramref name="defaultText"/></returns>

		public static string Load( string libraryName, UInt32 ident, string defaultText )

```
		{
```

			IntPtr libraryHandle = GetModuleHandle( libraryName );

```
			if ( libraryHandle != IntPtr.Zero )
```
```
			{
```

				StringBuilder sb = new StringBuilder( 1024 );

				int size = LoadString( libraryHandle, ident, sb, 1024 );

```
				if ( size > 0 )
```
```
					return sb.ToString( );
```
```
			}
```
```
			return defaultText;
```
```
		}
```
```
 
```

		[DllImport( "kernel32.dll", CharSet = CharSet.Auto )]

		private static extern IntPtr GetModuleHandle( string lpModuleName );

```
 
```

		[DllImport( "user32.dll", CharSet = CharSet.Auto )]

		private static extern int LoadString( IntPtr hInstance, UInt32 uID, StringBuilder lpBuffer, Int32 nBufferMax );

```
 
```
```
		#endregion Get Localized Captions
```
```
 
```
```
 
```
```
		#region Extract Icons
```
```
 
```

		// Code to extract icons from Shell32.dll by Thomas Levesque

		// http://stackoverflow.com/questions/6873026

```
 
```
```
		public class IconExtractor
```
```
		{
```
```
 
```

			public static Icon Extract( string file, int number, bool largeIcon )

```
			{
```
```
				IntPtr large;
```
```
				IntPtr small;
```

				ExtractIconEx( file, number, out large, out small, 1 );

```
				try
```
```
				{
```

					return Icon.FromHandle( largeIcon ? large : small );

```
				}
```
```
				catch
```
```
				{
```
```
					return null;
```
```
				}
```
```
 
```
```
			}
```
```
 
```

			[DllImport( "Shell32.dll", EntryPoint = "ExtractIconExW", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall )]

			private static extern int ExtractIconEx( string sFile, int iIndex, out IntPtr piLargeVersion, out IntPtr piSmallVersion, int amountIcons );

```
		}
```
```
 
```
```
		#endregion Extract Icons
```
```
	}
```
```
}
```
```
 
```