Added attempt on calling StatusUtf8. Doesn't seem to work.

samples/NetCoreConsole/Program.cs

@@ -46,7 +46,7 @@ namespace ConsoleApp
 
                         if (targetSrc != null)
                         {
-                            TestThisSource(targetSrc);
+                            TestThisSource(session, targetSrc);
                         }
                         else
                         {
@@ -67,12 +67,16 @@ namespace ConsoleApp
             Console.ReadLine();
         }
 
-        private static void TestThisSource(DataSource targetSrc)
+        private static void TestThisSource(TwainSession session, DataSource targetSrc)
         {
             Console.WriteLine($"Testing data source {targetSrc}");
             Console.WriteLine();
 
             targetSrc.Open();
+
+            var testStatus = session.GetStatus();
+            var testMessage = session.GetLocalizedStatus(ref testStatus);
+
             targetSrc.Close();
         }
 

src/NTwain/Data/TwainTypes.cs

@@ -513,12 +513,9 @@ namespace NTwain.Data
     [StructLayout(LayoutKind.Sequential, Pack = 2)]
     partial struct TW_STATUSUTF8
     {
-        // NOTE: rather than embedding the TWStatus directly I'm using its fields instead
+        public TW_STATUS Status;
-        // so the TWStatus could become a class object. 
+        public TW_UINT32 Size;
-        TW_UINT16 _conditionCode;
+        public TW_HANDLE UTF8string;
-        TW_UINT16 _data;
-        TW_UINT32 _size;
-        TW_HANDLE _uTF8string;
     }
 
     [StructLayout(LayoutKind.Sequential, Pack = 2)]

src/NTwain/Data/TwainTypesExtended.cs

@@ -2215,89 +2215,6 @@ namespace NTwain.Data
         public ushort Data { get { return _data; } }
     }
 
-    //    /// <summary>
-    //    /// Translates the contents of Status into a localized UTF8string, with the total number of bytes
-    //    /// in the string.
-    //    /// </summary>
-    //    public sealed partial struct TW_STATUSUTF8 : IDisposable
-    //    {
-    //        /// <summary>
-    //        /// <see cref="TW_STATUS"/> data received from a previous call.
-    //        /// </summary>
-    //        public TW_STATUS Status
-    //        {
-    //            get { return new TW_STATUS(_conditionCode, _data); }
-    //        }
-
-    //        /// <summary>
-    //        /// Total number of bytes in the UTF8string, plus the terminating NULL byte. 
-    //        /// This is not the same as the total number of characters in the string.
-    //        /// </summary>
-    //        public int Size { get { return (int)_size; } }
-
-    //        /// <summary>
-    //        /// TW_HANDLE to a UTF-8 encoded localized string (based on 
-    //        /// TW_IDENTITY.Language or CapLanguage). The Source allocates
-    //        /// it, the Application frees it.
-    //        /// </summary>
-    //        public IntPtr UTF8StringPtr { get { return _uTF8string; } }
-
-    //        /// <summary>
-    //        /// Gets the actual string from the pointer. This may be incorrect.
-    //        /// </summary>
-    //        /// <returns></returns>
-    //        public string TryGetString()
-    //        {
-    //            if (_uTF8string != IntPtr.Zero)
-    //            {
-    //                var sb = new StringBuilder(Size - 1);
-    //                byte bt;
-    //                while (sb.Length < _size &&
-    //                    (bt = Marshal.ReadByte(_uTF8string, sb.Length)) != 0)
-    //                {
-    //                    sb.Append((char)bt);
-    //                }
-    //                return sb.ToString();
-    //            }
-    //            return null;
-    //        }
-
-
-    //        #region IDisposable Members
-
-    //        /// <summary>
-    //        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
-    //        /// </summary>
-    //        public void Dispose()
-    //        {
-    //            Dispose(true);
-    //            GC.SuppressFinalize(this);
-    //        }
-
-    //        void Dispose(bool disposing)
-    //        {
-    //            if (disposing)
-    //            {
-
-    //            }
-    //            if (_uTF8string != IntPtr.Zero)
-    //            {
-    //                PlatformInfo.Current.MemoryManager.Free(_uTF8string);
-    //                _uTF8string = IntPtr.Zero;
-    //            }
-    //        }
-
-    //        /// <summary>
-    //        /// Finalizes an instance of the <see cref="TW_STATUSUTF8"/> class.
-    //        /// </summary>
-    //        ~TW_STATUSUTF8()
-    //        {
-    //            Dispose(false);
-    //        }
-
-    //        #endregion
-    //    }
-
     /// <summary>
     /// Provides identification information about a TWAIN entity. Used to maintain consistent
     /// communication between entities.

src/NTwain/Triplets/Control/StatusUtf8.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+using NTwain.Data;
+using NTwain.Internals;
+
+namespace NTwain.Triplets.Control
+{
+    sealed class StatusUtf8 : BaseTriplet
+    {
+        internal StatusUtf8(TwainSession session) : base(session) { }
+
+        public ReturnCode Get(ref TW_STATUS status, out string message)
+        {
+            message = null;
+            var rc = ReturnCode.Failure;
+
+            TW_STATUSUTF8 real = new TW_STATUSUTF8 { Status = status };
+            if (Use32BitData)
+            {
+                rc = NativeMethods.Dsm32(Session.Config.App32, Session.CurrentSource?.Identity,
+                    DataGroups.Control, DataArgumentType.StatusUtf8, Message.Get, ref real);
+            }
+
+            if (rc == ReturnCode.Success)
+            {
+                message = ReadUtf8String(ref real);
+            }
+
+            return rc;
+        }
+
+
+        private string ReadUtf8String(ref TW_STATUSUTF8 status)
+        {
+            if (status.UTF8string != IntPtr.Zero)
+            {
+                try
+                {
+                    IntPtr lockedPtr = Session.Config.MemoryManager.Lock(status.UTF8string);
+                    var buffer = new byte[status.Size - 1];
+
+                    Marshal.Copy(lockedPtr, buffer, 0, buffer.Length);
+                    return Encoding.UTF8.GetString(buffer);
+
+                }
+                finally
+                {
+                    Session.Config.MemoryManager.Unlock(status.UTF8string);
+                    Session.Config.MemoryManager.Free(status.UTF8string);
+                }
+            }
+            return null;
+        }
+    }
+}

src/NTwain/Triplets/DGControl.cs

@@ -33,6 +33,9 @@ namespace NTwain.Triplets
         Status _status;
         internal Status Status => _status ?? (_status = new Status(Session));
 
+        StatusUtf8 _statusUtf8;
+        internal StatusUtf8 StatusUtf8 => _statusUtf8 ?? (_statusUtf8 = new StatusUtf8(Session));
+
         DeviceEvent _devEvent;
         internal DeviceEvent DeviceEvent => _devEvent ?? (_devEvent = new DeviceEvent(Session));
     }

src/NTwain/TwainSession.cs

@@ -93,6 +93,17 @@ namespace NTwain
             return stat;
         }
 
+        /// <summary>
+        /// Gets the translated string for a <see cref="TW_STATUS"/>.
+        /// </summary>
+        /// <param name="status"></param>
+        /// <returns></returns>
+        public string GetLocalizedStatus(ref TW_STATUS status)
+        {
+            var rc = DGControl.StatusUtf8.Get(ref status, out string message);
+            return message;
+        }
+
         internal void RegisterCallback()
         {
             var callbackPtr = Marshal.GetFunctionPointerForDelegate(_callbackDelegate);