From 19e4cd0699d73b61208160b40f520f2c0ae83689 Mon Sep 17 00:00:00 2001
From: David Hall <dahall@byu.net>
Date: Sun, 22 Jul 2018 11:44:27 -0600
Subject: [PATCH] Added IShellPropSheetExt and supporting code.

---
 PInvoke/Shell32/ShObjIdl.IShellPropSheetExt.cs | 74 ++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 PInvoke/Shell32/ShObjIdl.IShellPropSheetExt.cs

diff --git a/PInvoke/Shell32/ShObjIdl.IShellPropSheetExt.cs b/PInvoke/Shell32/ShObjIdl.IShellPropSheetExt.cs
new file mode 100644
index 00000000..a9be3b7a
--- /dev/null
+++ b/PInvoke/Shell32/ShObjIdl.IShellPropSheetExt.cs
@@ -0,0 +1,74 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Vanara.PInvoke
+{
+	public static partial class Shell32
+	{
+		/// <summary>
+		/// A function that the property sheet handler calls to add a page to the property sheet. The function takes a property sheet handle
+		/// returned by the CreatePropertySheetPage function and the lParam parameter passed to that method.
+		/// </summary>
+		/// <param name="hPropSheetPage">A property sheet handle returned by the CreatePropertySheetPage function.</param>
+		/// <param name="lParam">The lParam parameter passed to the CreatePropertySheetPage function.</param>
+		/// <returns></returns>
+		[PInvokeData("Shobjidl.h")]
+		[UnmanagedFunctionPointer(CallingConvention.Winapi)]
+		public delegate bool LPFNSVADDPROPSHEETPAGE(IntPtr hPropSheetPage, IntPtr lParam);
+
+		/// <summary>Used by IShellPropSheetExt::ReplacePage.</summary>
+		[PInvokeData("Shobjidl.h")]
+		public enum EXPPS
+		{
+			/// <summary>Undocumented.</summary>
+			EXPPS_FILETYPES = 0x00000001,
+		}
+
+		/// <summary>Exposes methods that allow a property sheet handler to add or replace pages in the property sheet displayed for a file object.</summary>
+		[ComImport, Guid("000214E9-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+		[PInvokeData("Shobjidl.h")]
+		public interface IShellPropSheetExt
+		{
+			/// <summary>
+			/// Adds one or more pages to a property sheet that the Shell displays for a file object. The Shell calls this method for each
+			/// property sheet handler registered to the file type.
+			/// </summary>
+			/// <param name="pfnAddPage">
+			/// A pointer to a function that the property sheet handler calls to add a page to the property sheet. The function takes a
+			/// property sheet handle returned by the CreatePropertySheetPage function and the lParam parameter passed to this method.
+			/// </param>
+			/// <param name="lParam">Handler-specific data to pass to the function pointed to by pfnAddPage.</param>
+			/// <returns>
+			/// If successful, returns a one-based index to specify the page that should be initially displayed. See Remarks for more information.
+			/// </returns>
+			/// <remarks>
+			/// For each page that the property sheet handler needs to add to a property sheet, the handler fills a PROPSHEETPAGE structure,
+			/// calls the CreatePropertySheetPage function, and then calls the function pointed to by pfnAddPage.
+			/// <para>
+			/// You can request through your implementation that a particular property sheet page be displayed first, instead of the default
+			/// page. To do so, return the one-based index of the desired page relative to the pages you added. For example, if you added
+			/// three property sheet pages, A, B, and C, and you want B to be the selected page, then the return value should be 2. Note that
+			/// this return value is only a request. The property sheet might still display the default page.
+			/// </para>
+			/// </remarks>
+			uint AddPages([In] LPFNSVADDPROPSHEETPAGE pfnAddPage, [In] IntPtr lParam);
+
+			/// <summary>Replaces a page in a property sheet for a Control Panel object.</summary>
+			/// <param name="uPageID">
+			/// Not used.
+			/// <para><c>Microsoft Windows XP and earlier:</c> A type EXPPS identifier of the page to replace.</para>
+			/// </param>
+			/// <param name="pfnReplaceWith">
+			/// A pointer to a function that the property sheet handler calls to replace a page to the property sheet. The function takes a
+			/// property sheet handle returned by the CreatePropertySheetPage function and the lParam parameter passed to this method.
+			/// </param>
+			/// <param name="lParam">The parameter to pass to the function specified by the pfnReplacePage parameter.</param>
+			/// <returns>If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.</returns>
+			/// <remarks>
+			/// To replace a page, a property sheet handler fills a PROPSHEETPAGE structure, calls CreatePropertySheetPage, and then calls
+			/// the function specified by pfnReplacePage.
+			/// </remarks>
+			HRESULT ReplacePage([In] EXPPS uPageID, [In] LPFNSVADDPROPSHEETPAGE pfnReplaceWith, [In] IntPtr lParam);
+		}
+	}
+}
\ No newline at end of file