Added SetupFileXfer triplets.

src/NTwain/Triplets/Control/SetupFileXfer.cs

@@ -0,0 +1,88 @@
+using NTwain.Data;
+using NTwain.Internals;
+
+namespace NTwain.Triplets.Control
+{
+    /// <summary>
+    /// Represents <see cref="DataArgumentType.SetupFileXfer"/>.
+    /// </summary>
+    public sealed class SetupFileXfer : BaseTriplet
+	{
+		internal SetupFileXfer(TwainSession session) : base(session) { }
+
+        ReturnCode DoIt(Message msg, ref TW_SETUPFILEXFER xfer)
+        {
+            if (Is32Bit)
+            {
+                if (IsWin)
+                    return NativeMethods.DsmWin32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+                if (IsLinux)
+                    return NativeMethods.DsmLinux32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+                if (IsMac)
+                    return NativeMethods.DsmMac32(Session.Config.App32, Session.CurrentSource.Identity32,
+                        DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+            }
+
+            if (IsWin)
+                return NativeMethods.DsmWin64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+            if (IsLinux)
+                return NativeMethods.DsmLinux64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+            if (IsMac)
+                return NativeMethods.DsmMac64(Session.Config.App32, Session.CurrentSource.Identity32,
+                    DataGroups.Control, DataArgumentType.SetupFileXfer, msg, ref xfer);
+
+            return ReturnCode.Failure;
+        }
+
+        /// <summary>
+        /// Returns information about the file into which the Source has or will put the acquired image
+        /// or audio data.
+        /// </summary>
+        /// <param name="setupFileXfer">The setup file xfer.</param>
+        /// <returns></returns>
+        public ReturnCode Get(ref TW_SETUPFILEXFER setupFileXfer)
+		{
+            return DoIt(Message.Get, ref setupFileXfer);
+		}
+
+		/// <summary>
+		/// Returns information for the default image or audio file.
+		/// </summary>
+		/// <param name="setupFileXfer">The setup file xfer.</param>
+		/// <returns></returns>
+        public ReturnCode GetDefault(ref TW_SETUPFILEXFER setupFileXfer)
+        {
+            return DoIt(Message.GetDefault, ref setupFileXfer);
+        }
+
+		/// <summary>
+		/// Resets the current file information to the image or audio default file information and
+		/// returns that default information.
+		/// </summary>
+		/// <param name="setupFileXfer">The setup file xfer.</param>
+		/// <returns></returns>
+        public ReturnCode Reset(ref TW_SETUPFILEXFER setupFileXfer)
+        {
+            return DoIt(Message.Reset, ref setupFileXfer);
+        }
+
+		/// <summary>
+		/// Sets the file transfer information for the next file transfer. The application is responsible for
+		/// verifying that the specified file name is valid and that the file either does not currently exist (in
+		/// which case, the Source is to create the file), or that the existing file is available for opening and
+		/// read/write operations. The application should also assure that the file format it is requesting
+		/// can be provided by the Source
+		/// </summary>
+		/// <param name="setupFileXfer">The setup file xfer.</param>
+		/// <returns></returns>
+        public ReturnCode Set(ref TW_SETUPFILEXFER setupFileXfer)
+        {
+            return DoIt(Message.Set, ref setupFileXfer);
+        }
+
+	}
+}

src/NTwain/Triplets/DGControl.cs

@@ -63,6 +63,12 @@ namespace NTwain.Triplets
         /// </summary>
         public SetupMemXfer SetupMemXfer => _memXfer ?? (_memXfer = new SetupMemXfer(Session));
 
+        SetupFileXfer _fileXfer;
+        /// <summary>
+        /// Gets the operations defined for DAT_SETUPFILEXFER.
+        /// </summary>
+        public SetupFileXfer SetupFileXfer => _fileXfer ?? (_fileXfer = new SetupFileXfer(Session));
+
         FileSystem _fs;
         /// <summary>
         /// Gets the operations defined for DAT_FILESYSTEM.

src/NTwain/TwainSession.MsgHandling.cs

@@ -106,7 +106,7 @@ namespace NTwain
             var xMech = GetTransferMechs();
 
             TW_PENDINGXFERS pending = default;
-            var rc = DGControl.PendingXfers.Get(pending);
+            var rc = DGControl.PendingXfers.Get(ref pending);
             if (rc == ReturnCode.Success)
             {
                 do
@@ -122,7 +122,7 @@ namespace NTwain
 
                     if (readyArgs.CancelAll || _disableDSNow)
                     {
-                        rc = DGControl.PendingXfers.Reset(pending);
+                        rc = DGControl.PendingXfers.Reset(ref pending);
                     }
                     else
                     {
@@ -165,11 +165,11 @@ namespace NTwain
                         if (rc != ReturnCode.Success)// && StopOnTransferError)
                         {
                             // end xfer without setting rc to exit (good/bad?)
-                            DGControl.PendingXfers.Reset(pending);
+                            DGControl.PendingXfers.Reset(ref pending);
                         }
                         else
                         {
-                            rc = DGControl.PendingXfers.EndXfer(pending);
+                            rc = DGControl.PendingXfers.EndXfer(ref pending);
                         }
                     }
                     #endregion