C# does Shell, Part 4

using System;
using System.Runtime.InteropServices;

namespace ShellLib
{
	public class ShellAutoComplete
	{

		public static Boolean DoAutoComplete(IntPtr hwndEdit, AutoCompleteFlags flags)
		{
			Int32 hRet;
			hRet = ShellApi.SHAutoComplete(hwndEdit, (UInt32)flags);
            return (hRet == 0);
		}
		
		[Flags]
		public enum AutoCompleteFlags : uint
		{
			/// <summary>
			/// The default setting, equivalent to FileSystem | UrlAll. Default cannot be
			///  combined with any other flags.
			/// </summary>
			Default                   = 0x00000000,
			/// <summary>
			/// This includes the File System as well as the rest of the shell 
			/// (Desktop\My Computer\Control Panel\)
			/// </summary>
			FileSystem                = 0x00000001,  
			/// <summary>
			/// Include the URLs in the users History and Recently Used lists. Equivalent 
			/// to UrlHistory | UrlMRU.
			/// </summary>
			UrlAll                    = (UrlHistory | UrlMRU),
			/// <summary>
			/// Include the URLs in the user's History list.
			/// </summary>
			UrlHistory                = 0x00000002,
			/// <summary>
			/// Include the URLs in the user's Recently Used list.
			/// </summary>
			UrlMRU                    = 0x00000004,  
			/// <summary>
			/// Allow the user to select from the autosuggest list by pressing the TAB 
			/// key. If this flag is not set, pressing the TAB key will shift focus to 
			/// the next control and close the autosuggest list. If UseTab is set, 
			/// pressing the TAB key will select the first item in the list. Pressing 
			/// TAB again will select the next item in the list, and so on. When the user 
			/// reaches the end of the list, the next TAB key press will cycle the focus 
			/// back to the edit control. This flag must be used in combination with one 
			/// or more of the FileSys* or Url* flags.
			/// </summary>
			UseTab                    = 0x00000008,  
			/// <summary>
			/// This includes the File System
			/// </summary>
			FileSys_Only              = 0x00000010,  
			/// <summary>
			/// Same as FileSys_Only except it only includes directories, UNC servers, 
			/// and UNC server shares.
			/// </summary>
			FileSys_Dirs              = 0x00000020,  
			/// <summary>
			/// Ignore the registry value and force the autosuggest feature on. A 
			/// selection of possible completed strings will be displayed as a drop-down 
			/// list, below the edit box. This flag must be used in combination with one
			///  or more of the FileSys* or Url* flags.
			/// </summary>
			AutoSuggest_Force_On      = 0x10000000,
			/// <summary>
			/// Ignore the registry default and force the autosuggest feature off. This 
			/// flag must be used in combination with one or more of the FileSys* or 
			/// Url* flags.
			/// </summary>
			AutoSuggest_Force_Off     = 0x20000000,  
			/// <summary>
			/// Ignore the registry value and force the autoappend feature on. The 
			/// completed string will be displayed in the edit box with the added 
			/// characters highlighted. This flag must be used in combination with one 
			/// or more of the FileSys* or Url* flags.
			/// </summary>
			AutoAppend_Force_On       = 0x40000000,  
			/// <summary>
			/// Ignore the registry default and force the autoappend feature off. This 
			/// flag must be used in combination with one or more of the FileSys* or 
			/// Url* flags.
			/// </summary>
			AutoAppend_Force_Off      = 0x80000000  
		}


		[Flags]
		public enum AutoCompleteListOptions
		{
			None            = 0,		// don't enumerate anything
			CurrentDir      = 1,		// enumerate current directory
			MyComputer      = 2,		// enumerate MyComputer
			Desktop         = 4,		// enumerate Desktop Folder
			Favorites       = 8,		// enumerate Favorites Folder
			FileSysOnly     = 16,		// enumerate only the file system
			FileSysDirs     = 32		// enumerate only the file system dirs, UNC shares, and UNC servers.
		}
		

		[Flags]
		public enum AutoCompleteOptions
		{
			None					= 0,
			AutoSuggest				= 0x1,
			AutoAppend				= 0x2,
			Search					= 0x4,
			FilterPreFixes			= 0x8,
			UseTab					= 0x10,
			UpDownKeyDropsList		= 0x20,
			RtlReading				= 0x40
		} 	
		

		public ShellAutoComplete()
		{
		}

		public IntPtr EditHandle = IntPtr.Zero;
		public Object ListSource = null;
		public AutoCompleteOptions ACOptions = AutoCompleteOptions.AutoSuggest | AutoCompleteOptions.AutoAppend;

		private Object GetAutoComplete()
		{
			Type typeAutoComplete = Type.GetTypeFromCLSID(ShellGUIDs.CLSID_AutoComplete);

			Object obj;
			obj = Activator.CreateInstance(typeAutoComplete);
			return obj;
		}

		public static Object GetACLHistory()
		{
			Type typeACLHistory = Type.GetTypeFromCLSID(ShellGUIDs.CLSID_ACLHistory);

			Object obj;
			obj = Activator.CreateInstance(typeACLHistory);
			return obj;
		}

		public static Object GetACLMRU()
		{
			Type typeACLMRU = Type.GetTypeFromCLSID(ShellGUIDs.CLSID_ACLMRU);

			Object obj;
			obj = Activator.CreateInstance(typeACLMRU);
			return obj;
		}

		public static Object GetACListISF()
		{
			Type typeACListISF = Type.GetTypeFromCLSID(ShellGUIDs.CLSID_ACListISF);

			Object obj;
			obj = Activator.CreateInstance(typeACListISF);
			return obj;
		}

		public static Object GetACLMulti()
		{
			Type typeACLMulti = Type.GetTypeFromCLSID(ShellGUIDs.CLSID_ACLMulti);

			Object obj;
			obj = Activator.CreateInstance(typeACLMulti);
			return obj;
		}


		public void SetAutoComplete(Boolean enable)
		{
			Int32 ret;
			IAutoComplete2 iac2 = (IAutoComplete2)GetAutoComplete();
			
			if (EditHandle == IntPtr.Zero)
				throw new Exception("EditHandle must not be zero!");
			
			if (ListSource == null)
				throw new Exception("ListSource must not be null!");
			
			
			ret = iac2.Init(EditHandle,ListSource,"","");
			
			ret = iac2.SetOptions((UInt32)ACOptions);
			
			ret= iac2.Enable(enable ? 1 : 0);
						
			Marshal.ReleaseComObject(iac2);
				
		}

		


	
	}

}