Fixed bug with CoTaskMemStringMarshaler being used for return values and is never called. Added marshaler to places where appropriate.

PInvoke/Ole/PropSys/PropSys.cs

@@ -387,14 +387,26 @@ namespace Vanara.PInvoke
 			PDCOT_NUMBER	= 5
 		}
 
+		/// <summary>Gets an instance of a property description interface for a property specified by a PROPERTYKEY structure.</summary>
+		/// <param name="propkey">Reference to a PROPERTYKEY.</param>
+		/// <param name="riid">Reference to the interface ID of the requested interface.</param>
+		/// <param name="ppv">
+		/// When this function returns, contains the interface pointer requested in riid. This is typically IPropertyDescription, IPropertyDescriptionAliasInfo,
+		/// or IPropertyDescriptionSearchInfo.
+		/// </param>
+		/// <returns></returns>
+		[DllImport(Lib.PropSys, ExactSpelling = true)]
+		[PInvokeData("Propsys.h", MSDNShortId = "bb776503")]
+		public static extern HRESULT PSGetPropertyDescription(ref PROPERTYKEY propkey, [MarshalAs(UnmanagedType.LPStruct)] Guid riid, [MarshalAs(UnmanagedType.Interface)] out object ppv);
+
 		/// <summary>
 		/// Retrieves the property's canonical name given its PROPERTYKEY.
 		/// </summary>
 		/// <param name="propkey">A pointer to a PROPERTYKEY structure containing the property's identifiers.</param>
-		/// <param name="ppszCanonicalName">The address of a pointer to a buffer that receives the property name as a null-terminated Unicode string. It is the responsibility of the caller to release this string through a call to CoTaskMemFree once it is no longer needed.</param>
+		/// <param name="ppszCanonicalName">The address of a pointer to a buffer that receives the property name as a null-terminated Unicode string.</param>
 		[DllImport(Lib.PropSys, ExactSpelling = true)]
 		[PInvokeData("Propsys.h", MSDNShortId = "bb776502")]
-		public static extern HRESULT PSGetNameFromPropertyKey(ref PROPERTYKEY propkey, out SafeCoTaskMemString ppszCanonicalName);
+		public static extern HRESULT PSGetNameFromPropertyKey(ref PROPERTYKEY propkey, [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))] out string ppszCanonicalName);
 
 		[ComImport, Guid("1F9FC1D0-C39B-4B26-817F-011967D3440E"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
 		[PInvokeData("Propsys.h", MSDNShortId = "bb761511")]
@@ -414,19 +426,16 @@ namespace Vanara.PInvoke
 			PROPERTYKEY GetPropertyKey();
 			/// <summary>Gets the case-sensitive name by which a property is known to the system, regardless of its localized name.</summary>
 			/// <returns>When this method returns, contains the address of a pointer to the property's canonical name as a null-terminated Unicode string.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetCanonicalName();
+			SafeCoTaskMemString GetCanonicalName();
 			/// <summary>Gets the variant type of the property.</summary>
 			/// <returns>When this method returns, contains a pointer to a VARTYPE that indicates the property type. If the property is multi-valued, the value pointed to is a VT_VECTOR mask (VT_VECTOR ORed to the VARTYPE.</returns>
 			VARTYPE GetPropertyType();
 			/// <summary>Gets the display name of the property as it is shown in any UI.</summary>
 			/// <returns>Contains the address of a pointer to the property's name as a null-terminated Unicode string.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetDisplayName();
+			SafeCoTaskMemString GetDisplayName();
 			/// <summary>Gets the text used in edit controls hosted in various dialog boxes.</summary>
 			/// <returns>When this method returns, contains the address of a pointer to a null-terminated Unicode buffer that holds the invitation text.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetEditInvitation();
+			SafeCoTaskMemString GetEditInvitation();
 			/// <summary>Gets a set of flags that describe the uses and capabilities of the property.</summary>
 			/// <param name="mask">A mask that specifies which type flags to retrieve. A combination of values found in the PROPDESC_TYPE_FLAGS constants. To retrieve all type flags, pass PDTF_MASK_ALL</param>
 			/// <returns>When this method returns, contains a pointer to a value that consists of bitwise PROPDESC_TYPE_FLAGS values.</returns>
@@ -461,8 +470,7 @@ namespace Vanara.PInvoke
 			/// <summary>Gets the localized display string that describes the current sort order.</summary>
 			/// <param name="fDescending">TRUE if ppszDescription should reference the string "Z on top"; FALSE to reference the string "A on top".</param>
 			/// <returns>When this method returns, contains the address of a pointer to the sort description as a null-terminated Unicode string.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetSortDescriptionLabel([In, MarshalAs(UnmanagedType.Bool)] bool fDescending);
+			SafeCoTaskMemString GetSortDescriptionLabel([In, MarshalAs(UnmanagedType.Bool)] bool fDescending);
 			/// <summary>Gets a value that describes how the property values are displayed when multiple items are selected in the UI.</summary>
 			/// <returns>When this method returns, contains a pointer to a value that indicates the aggregation type.</returns>
 			PROPDESC_AGGREGATION_TYPE GetAggregationType();

PInvoke/Ole/PropSys/PropvarUtil.cs

@@ -422,7 +422,7 @@ namespace Vanara.PInvoke
 		/// <returns>If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.</returns>
 		[DllImport(Lib.PropSys, ExactSpelling = true)]
 		[PInvokeData("Propvarutil.h", MSDNShortId = "bb776560")]
-		public static extern HRESULT PropVariantToStringAlloc([In] PROPVARIANT propVar,  out SafeCoTaskMemString ppszOut);
+		public static extern HRESULT PropVariantToStringAlloc([In] PROPVARIANT propVar, [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))] out string ppszOut);
 
 		/// <summary>Extracts data from a <see cref="PROPVARIANT" /> structure into a newly allocated strings in a newly allocated vector.</summary>
 		/// <param name="propVar">Reference to the source <see cref="PROPVARIANT" /> structure.</param>

PInvoke/Shared/InteropServices/CoTaskMemStringMarshaler.cs

@@ -31,7 +31,7 @@ namespace Vanara.InteropServices
 		/// <param name="pNativeData">A pointer to the unmanaged data to be destroyed.</param>
 		public void CleanUpNativeData(IntPtr pNativeData)
 		{
-			StringHelper.FreeString(pNativeData, charSet);
+			Marshal.FreeCoTaskMem(pNativeData);
 		}
 
 		/// <summary>Returns the size of the native data to be marshaled.</summary>

PInvoke/Shell32/ShObjIdl.IFileDialog.cs

@@ -267,8 +267,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves the text currently entered in the dialog's File name edit box.</summary>
 			/// <returns>The address of a pointer to a buffer that, when this method returns successfully, receives the text.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler), MarshalCookie = "Unicode")]
-			string GetFileName();
+			SafeCoTaskMemString GetFileName();
 
 			/// <summary>Sets the title of the dialog.</summary>
 			/// <param name="pszTitle">A pointer to a buffer that contains the title text.</param>
@@ -491,8 +490,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves the text currently entered in the dialog's File name edit box.</summary>
 			/// <returns>The address of a pointer to a buffer that, when this method returns successfully, receives the text.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler), MarshalCookie = "Unicode")]
-			new string GetFileName();
+			new SafeCoTaskMemString GetFileName();
 
 			/// <summary>Sets the title of the dialog.</summary>
 			/// <param name="pszTitle">A pointer to a buffer that contains the title text.</param>
@@ -754,8 +752,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves the text currently entered in the dialog's File name edit box.</summary>
 			/// <returns>The address of a pointer to a buffer that, when this method returns successfully, receives the text.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler), MarshalCookie = "Unicode")]
-			new string GetFileName();
+			new SafeCoTaskMemString GetFileName();
 
 			/// <summary>Sets the title of the dialog.</summary>
 			/// <param name="pszTitle">A pointer to a buffer that contains the title text.</param>

PInvoke/Shell32/ShObjIdl.IKnownFolder.cs

@@ -743,8 +743,7 @@ namespace Vanara.PInvoke
 			/// When this method returns, contains the address of a pointer to a null-terminated buffer that contains the path. The calling application is
 			/// responsible for calling CoTaskMemFree to free this resource when it is no longer needed.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetPath([In] KNOWN_FOLDER_FLAG dwFlags);
+			SafeCoTaskMemString GetPath([In] KNOWN_FOLDER_FLAG dwFlags);
 
 			/// <summary>Assigns a new path to a known folder.</summary>
 			/// <param name="dwFlags">Either zero or the following value: KF_FLAG_DONT_UNEXPAND</param>
@@ -886,8 +885,7 @@ namespace Vanara.PInvoke
 			/// When this method returns, contains the address of a pointer to a null-terminated Unicode string that contains an error message if one was
 			/// generated. This value can be NULL.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string Redirect([In, MarshalAs(UnmanagedType.LPStruct)] Guid rfid, [In] IntPtr hwnd, [In] KF_REDIRECT_FLAGS flags,
+			SafeCoTaskMemString Redirect([In, MarshalAs(UnmanagedType.LPStruct)] Guid rfid, [In] IntPtr hwnd, [In] KF_REDIRECT_FLAGS flags,
 				[In, MarshalAs(UnmanagedType.LPWStr)] string pszTargetPath, [In] uint cFolders, [In, MarshalAs(UnmanagedType.LPStruct)] Guid pExclusion);
 		}
 

PInvoke/Shell32/ShObjIdl.IShellLibrary.cs

@@ -136,8 +136,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Gets the default icon for the library.</summary>
 			/// <returns>A null-terminated Unicode string that describes the location of the default icon. The string is returned as ModuleFileName,ResourceIndex or ModuleFileName,-ResourceID.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler), MarshalCookie = "Unicode")]
-			string GetIcon();
+			SafeCoTaskMemString GetIcon();
 
 			/// <summary>Sets the default icon for the library.</summary>
 			/// <param name="icon">A null-terminated Unicode string that describes the location of the default icon. The string must be formatted as ModuleFileName,ResourceIndex or ModuleFileName,-ResourceID.</param>

PInvoke/Shell32/ShObjIdl.ShellUtil.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Linq;
-using System.Runtime.InteropServices;
 using System.Security;
 using System.Text;
 
@@ -46,8 +45,8 @@ namespace Vanara.PInvoke
 					return null;
 
 				var pathBuilder = new StringBuilder(260);
-				try { SHGetFolderPathEx(knownFolder, 0, null, pathBuilder, (uint)pathBuilder.Capacity); }
-				catch { return null; }
+				if (SHGetFolderPathEx(knownFolder, 0, null, pathBuilder, (uint)pathBuilder.Capacity).Failed)
+				    return null;
 				return pathBuilder.ToString();
 			}
 
@@ -66,7 +65,7 @@ namespace Vanara.PInvoke
 				if (string.IsNullOrEmpty(path))
 					return null;
 
-				SHCreateItemFromParsingName(path, null, Marshal.GenerateGuidForType(typeof(IShellItem)), out object unk);
+				SHCreateItemFromParsingName(path, null, typeof(IShellItem).GUID, out object unk).ThrowIfFailed();
 				return (IShellItem)unk;
 			}
 		}

PInvoke/Shell32/ShObjIdl.cs

@@ -633,8 +633,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves a file type handler's explicit Application User Model ID (AppUserModelID), if one has been declared.</summary>
 			/// <returns></returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetAppID();
+			SafeCoTaskMemString GetAppID();
 		}
 
 		/// <summary>Exposes methods that provide access to the ProgID associated with an object.</summary>
@@ -649,8 +648,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves the ProgID associated with an object.</summary>
 			/// <returns>A pointer to a string that, when this method returns successfully, contains the ProgID.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetProgID();
+			SafeCoTaskMemString GetProgID();
 		}
 
 		/// <summary>
@@ -665,13 +663,11 @@ namespace Vanara.PInvoke
 			/// <param name="dwFlags">
 			/// Flags that direct the handling of the item from which you're retrieving the info tip text. This value is commonly zero (QITIPF_DEFAULT).
 			/// </param>
-			/// <returns>
-			/// The address of a Unicode string pointer that, when this method returns successfully, receives the tip string pointer. Applications that implement
+			/// <param name="ppwszTip">The address of a Unicode string pointer that, when this method returns successfully, receives the tip string pointer. Applications that implement
 			/// this method must allocate memory for ppwszTip by calling CoTaskMemAlloc. Calling applications must call CoTaskMemFree to free the memory when it
 			/// is no longer needed.
-			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetInfoTip(QITIP dwFlags);
+			/// </param>>
+			void GetInfoTip(QITIP dwFlags, [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))] out string ppwszTip);
 
 			/// <summary>Gets the information flags for an item. This method is not currently used.</summary>
 			/// <returns>A pointer to a value that receives the flags for the item. If no flags are to be returned, this value should be set to zero.</returns>
@@ -920,8 +916,7 @@ namespace Vanara.PInvoke
 			/// <summary>Gets the display name of the IShellItem object.</summary>
 			/// <param name="sigdnName">One of the SIGDN values that indicates how the name should look.</param>
 			/// <returns>A value that, when this function returns successfully, receives the address of a pointer to the retrieved display name.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetDisplayName(SIGDN sigdnName);
+			SafeCoTaskMemString GetDisplayName(SIGDN sigdnName);
 
 			/// <summary>Gets a requested set of attributes of the IShellItem object.</summary>
 			/// <param name="sfgaoMask">
@@ -972,8 +967,7 @@ namespace Vanara.PInvoke
 			/// <summary>Gets the display name of the IShellItem object.</summary>
 			/// <param name="sigdnName">One of the SIGDN values that indicates how the name should look.</param>
 			/// <returns>A value that, when this function returns successfully, receives the address of a pointer to the retrieved display name.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			new string GetDisplayName(SIGDN sigdnName);
+			new SafeCoTaskMemString GetDisplayName(SIGDN sigdnName);
 
 			/// <summary>Gets a requested set of attributes of the IShellItem object.</summary>
 			/// <param name="sfgaoMask">
@@ -1068,8 +1062,7 @@ namespace Vanara.PInvoke
 			/// <summary>Gets the string value of a specified property key.</summary>
 			/// <param name="key">A reference to a PROPERTYKEY structure.</param>
 			/// <returns>A pointer to a Unicode string value.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetString([In] ref PROPERTYKEY key);
+			SafeCoTaskMemString GetString([In] ref PROPERTYKEY key);
 
 			/// <summary>Gets the UInt32 value of specified property key.</summary>
 			/// <param name="key">A reference to a PROPERTYKEY structure.</param>
@@ -1283,9 +1276,9 @@ namespace Vanara.PInvoke
 		/// terminating null character.
 		/// </param>
 		/// <returns>Returns a pointer to an ITEMIDLIST structure that corresponds to the path.</returns>
-		[DllImport(Lib.Shell32, EntryPoint = "ILCreateFromPath", SetLastError = false)]
+		[DllImport(Lib.Shell32, EntryPoint = "ILCreateFromPathW", SetLastError = true)]
 		[PInvokeData("Shobjidl.h", MSDNShortId = "dd378420")]
-		public static extern IntPtr IntILCreateFromPath(string pszPath);
+		public static extern IntPtr IntILCreateFromPath([MarshalAs(UnmanagedType.LPWStr)] string pszPath);
 
 		/// <summary>
 		/// Specifies a unique application-defined Application User Model ID (AppUserModelID) that identifies the current process to the taskbar. This identifier

PInvoke/TaskSchd/MSTask.cs

@@ -560,8 +560,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the retrieved trigger description. Note that this string must be release by a call to
 			/// CoTaskMemFree after the string is no longer needed.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetTriggerString([In] ushort iTrigger);
+			SafeCoTaskMemString GetTriggerString([In] ushort iTrigger);
 
 			/// <summary>Retrieves the work item run times for a specified time period.</summary>
 			/// <param name="pstBegin">A pointer to a SYSTEMTIME structure that contains the starting time of the time period to check. This value is inclusive.</param>
@@ -635,8 +634,7 @@ namespace Vanara.PInvoke
 
 			/// <summary>Retrieves the comment for the work item.</summary>
 			/// <returns>A pointer to a null-terminated string that contains the retrieved comment for the current work item.</returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetComment();
+			SafeCoTaskMemString GetComment();
 
 			/// <summary>Sets the name of the work item's creator.</summary>
 			/// <param name="Creator">A null-terminated string that contains the name of the work item's creator.</param>
@@ -647,8 +645,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the name of the creator of the current work item. The application that invokes GetCreator is
 			/// responsible for freeing this string using the CoTaskMemFree function.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetCreator();
+			SafeCoTaskMemString GetCreator();
 
 			/// <summary>This method stores application-defined data associated with the work item.</summary>
 			/// <param name="cBytes">The number of bytes in the data buffer. The caller allocates and frees this memory.</param>
@@ -718,8 +715,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the account name for the current work item. The empty string, L"", is returned for the local
 			/// system account. After processing the account name, be sure to call CoTaskMemFree to free the string.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetAccountInformation();
+			SafeCoTaskMemString GetAccountInformation();
 
 			/// <summary>This method assigns a specific application to the current task.</summary>
 			/// <param name="pwszApplicationName">
@@ -733,8 +729,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the name of the application the current task is associated with. After processing this name,
 			/// call CoTaskMemFree to free resources.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetApplicationName();
+			SafeCoTaskMemString GetApplicationName();
 
 			/// <summary>This method sets the command-line parameters for the task.</summary>
 			/// <param name="pwszParameters">
@@ -748,8 +743,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the command-line parameters for the task. The method that invokes GetParameters is
 			/// responsible for freeing this string using the CoTaskMemFree function.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetParameters();
+			SafeCoTaskMemString GetParameters();
 
 			/// <summary>This method sets the working directory for the task.</summary>
 			/// <param name="pwszWorkingDirectory">
@@ -767,8 +761,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the task's working directory. The application that invokes GetWorkingDirectory is responsible
 			/// for freeing this string using the CoTaskMemFree function.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetWorkingDirectory();
+			SafeCoTaskMemString GetWorkingDirectory();
 
 			/// <summary>This method sets the priority for the task.</summary>
 			/// <param name="dwPriority">
@@ -842,8 +835,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a null-terminated string that contains the name of the target computer for the current task. This string is allocated by the
 			/// application that invokes GetTargetComputer, and must also be freed using CoTaskMemFree.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetTargetComputer();
+			SafeCoTaskMemString GetTargetComputer();
 
 			/// <summary>The Enum method retrieves a pointer to an OLE enumerator object that enumerates the tasks in the current task folder.</summary>
 			/// <returns>A pointer to a pointer to an IEnumWorkItems interface. This interface contains the enumeration context of the current task(s).</returns>
@@ -923,8 +915,7 @@ namespace Vanara.PInvoke
 			/// A pointer to a pointer to a null-terminated string that describes the current task trigger. The method that invokes GetTriggerString is
 			/// responsible for freeing this string using the CoTaskMemFree function.
 			/// </returns>
-			[return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(CoTaskMemStringMarshaler))]
-			string GetTriggerString();
+			SafeCoTaskMemString GetTriggerString();
 
 			/// <summary>The SetTrigger method sets the trigger criteria for a task trigger.</summary>
 			/// <param name="Trigger">A pointer to a TASK_TRIGGER structure that contains the values that define the new task trigger.</param>