Reduced ctors for TwainAppSession.

samples/WinConsole32/Program.cs

@@ -11,7 +11,7 @@ namespace WinConsole32
       var libVer = FileVersionInfo.GetVersionInfo(typeof(TwainAppSession).Assembly.Location).ProductVersion;
       Console.WriteLine($"Console sample {(TWPlatform.Is32bit ? " 32bit" : " 64bit")} on NTwain {libVer}");
 
-      TwainAppSession session = new TwainAppSession(Environment.ProcessPath!);
+      TwainAppSession session = new TwainAppSession(new TW_IDENTITY_LEGACY(Environment.ProcessPath!));
 
       session.StateChanged += Session_StateChanged;
       session.SourceDisabled += Session_SourceDisabled1;

samples/WinForm32/Form1.cs

@@ -37,7 +37,7 @@ namespace WinFormSample
 
       TWPlatform.PreferLegacyDSM = false;
 
-      twain = new TwainAppSession(Assembly.GetExecutingAssembly().Location);
+      twain = new TwainAppSession(new TW_IDENTITY_LEGACY(Assembly.GetExecutingAssembly().Location));
       twain.StateChanged += Twain_StateChanged;
       twain.DefaultSourceChanged += Twain_DefaultSourceChanged;
       twain.CurrentSourceChanged += Twain_CurrentSourceChanged;

src/NTwain/Data/TWAINH_EXTRAS.cs

@@ -1,7 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Globalization;
 using System.Runtime.InteropServices;
+using System.Text;
 
 namespace NTwain.Data
 {
@@ -32,6 +34,7 @@ namespace NTwain.Data
       }
 
 #else
+      Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
       if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
       {
         IsWindows = true;
@@ -657,6 +660,68 @@ namespace NTwain.Data
   }
   partial struct TW_IDENTITY_LEGACY
   {
+    /// <summary>
+    /// Creates app info derived an executable file.
+    /// </summary>
+    /// <param name="exeFilePath"></param>
+    /// <param name="appLanguage"></param>
+    /// <param name="appCountry"></param>
+    public TW_IDENTITY_LEGACY(
+      string exeFilePath,
+      TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA) :
+      this(FileVersionInfo.GetVersionInfo(exeFilePath), appLanguage, appCountry)
+    { }
+    /// <summary>
+    /// Creates app info derived from a <see cref="FileVersionInfo"/> object.
+    /// </summary>
+    /// <param name="appInfo"></param>
+    /// <param name="appLanguage"></param>
+    /// <param name="appCountry"></param>
+    public TW_IDENTITY_LEGACY(
+        FileVersionInfo appInfo,
+        TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA) :
+        this(
+          appInfo.CompanyName ?? "",
+          appInfo.ProductName ?? "",
+          appInfo.ProductName ?? "",
+          new Version(appInfo.FileVersion ?? "1.0"),
+          appInfo.FileDescription ?? "", appLanguage, appCountry)
+    { }
+    /// <summary>
+    /// Creates id with explicit app info.
+    /// </summary>
+    /// <param name="companyName"></param>
+    /// <param name="productFamily"></param>
+    /// <param name="productName"></param>
+    /// <param name="productVersion"></param>
+    /// <param name="productDescription"></param>
+    /// <param name="appLanguage"></param>
+    /// <param name="appCountry"></param>
+    /// <param name="supportedTypes"></param>
+    public TW_IDENTITY_LEGACY(
+        string companyName, string productFamily, string productName,
+        Version productVersion, string productDescription = "",
+        TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA,
+        DG supportedTypes = DG.IMAGE)
+    {
+      Manufacturer = companyName;
+      ProductFamily = productFamily;
+      ProductName = productName;
+      ProtocolMajor = (ushort)TWON_PROTOCOL.MAJOR;
+      ProtocolMinor = (ushort)TWON_PROTOCOL.MINOR;
+      SupportedGroups = (uint)(supportedTypes | DG.CONTROL | DG.APP2);
+      Version = new TW_VERSION
+      {
+        Country = appCountry,
+        Info = productDescription,
+        Language = appLanguage,
+        MajorNum = (ushort)productVersion.Major,
+        MinorNum = (ushort)productVersion.Minor,
+      };
+    }
+
+
+
     /// <summary>
     /// A simplified check on whether this has valid data from DSM.
     /// </summary>

src/NTwain/TwainAppSession.cs

@@ -1,13 +1,10 @@
 using NTwain.Data;
 using NTwain.Triplets;
 using System;
-using System.Collections.Concurrent;
-using System.Diagnostics;
 using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Xml;
 
 namespace NTwain
 {
@@ -15,81 +12,16 @@ namespace NTwain
 
   public partial class TwainAppSession : IDisposable
   {
-    static bool __encodingRegistered;
-
-    /// <summary>
-    /// Creates TWAIN session with app info derived an executable file.
-    /// </summary>
-    /// <param name="exeFilePath"></param>
-    /// <param name="appLanguage"></param>
-    /// <param name="appCountry"></param>
-    public TwainAppSession(
-      string exeFilePath,
-      TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA) :
-      this(FileVersionInfo.GetVersionInfo(exeFilePath), appLanguage, appCountry)
-    { }
-    /// <summary>
-    /// Creates TWAIN session with app info derived from a <see cref="FileVersionInfo"/> object.
-    /// </summary>
-    /// <param name="appInfo"></param>
-    /// <param name="appLanguage"></param>
-    /// <param name="appCountry"></param>
-    public TwainAppSession(
-        FileVersionInfo appInfo,
-        TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA) :
-        this(
-          appInfo.CompanyName ?? "",
-          appInfo.ProductName ?? "",
-          appInfo.ProductName ?? "",
-          new Version(appInfo.FileVersion ?? "1.0"),
-          appInfo.FileDescription ?? "", appLanguage, appCountry)
-    { }
     /// <summary>
     /// Creates TWAIN session with explicit app info.
     /// </summary>
-    /// <param name="companyName"></param>
+    /// <param name="appId"></param>
-    /// <param name="productFamily"></param>
+    public TwainAppSession(TW_IDENTITY_LEGACY appId)
-    /// <param name="productName"></param>
-    /// <param name="productVersion"></param>
-    /// <param name="productDescription"></param>
-    /// <param name="appLanguage"></param>
-    /// <param name="appCountry"></param>
-    /// <param name="supportedTypes"></param>
-    public TwainAppSession(
-        string companyName, string productFamily, string productName,
-        Version productVersion, string productDescription = "",
-        TWLG appLanguage = TWLG.ENGLISH_USA, TWCY appCountry = TWCY.USA,
-        DG supportedTypes = DG.IMAGE)
     {
 #if WINDOWS || NETFRAMEWORK
       DSM.DsmLoader.TryLoadCustomDSM();
 #endif
-      // todo: find a better place for this
+      _appIdentity = appId;
-      if (!__encodingRegistered)
-      {
-#if !NETFRAMEWORK
-        Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
-#endif
-        __encodingRegistered = true;
-      }
-
-      _appIdentity = new()
-      {
-        Manufacturer = companyName,
-        ProductFamily = productFamily,
-        ProductName = productName,
-        ProtocolMajor = (ushort)TWON_PROTOCOL.MAJOR,
-        ProtocolMinor = (ushort)TWON_PROTOCOL.MINOR,
-        SupportedGroups = (uint)(supportedTypes | DG.CONTROL | DG.APP2),
-        Version = new TW_VERSION
-        {
-          Country = appCountry,
-          Info = productDescription,
-          Language = appLanguage,
-          MajorNum = (ushort)productVersion.Major,
-          MinorNum = (ushort)productVersion.Minor,
-        }
-      };
 
       _legacyCallbackDelegate = LegacyCallbackHandler;
       _osxCallbackDelegate = OSXCallbackHandler;
@@ -97,6 +29,7 @@ namespace NTwain
       StartTransferThread();
     }
 
+
     internal IntPtr _hwnd;
     internal TW_USERINTERFACE _userInterface; // kept around for disable to use
 #if WINDOWS || NETFRAMEWORK