Added cap value report saver to wpf sample.

samples/Sample.WPF/MainWindow.xaml

@@ -44,7 +44,10 @@
             </ListBox.ItemTemplate>
         </ListBox>
 
-        <Label Content="Caps" Grid.Column="1"></Label>
+        <StackPanel Orientation="Horizontal" Grid.Column="1">
+            <Label Content="Caps" Grid.Column="1"></Label>
+            <Button Content="Save Reported" Command="{Binding SaveCapValuesCommand}" DataContext="{Binding SelectedSource}"></Button>
+        </StackPanel>
         <TextBox Text="{Binding CapFilter, UpdateSourceTrigger=PropertyChanged}" DataContext="{Binding SelectedSource}"
                  Grid.Column="1" Grid.Row="1"
                  modern:TextBoxUI.WatermarkText="Find cap name"></TextBox>

samples/Sample.WPF/MainWindow.xaml.cs

@@ -34,10 +34,7 @@ namespace Sample.WPF
                 Messenger.Default.Register<RefreshCommandsMessage>(this, m => m.HandleIt());
                 Messenger.Default.Register<ChooseFileMessage>(this, m =>
                 {
-                    if (m.Sender == DataContext)
-                    {
                         m.HandleWithPlatform(this);
-                    }
                 });
                 Messenger.Default.Register<MessageBoxMessage>(this, msg =>
                 {
@@ -78,6 +75,7 @@ namespace Sample.WPF
         }
         protected override void OnClosed(EventArgs e)
         {
+            Messenger.Default.Unregister(this);
             _twainVM.CloseDown();
             base.OnClosed(e);
         }

samples/Sample.WPF/ViewModels/CapVM.cs

@@ -75,8 +75,6 @@ namespace Sample.WPF
             }
         }
 
-        public object MyProperty { get; set; }
-
         public CapabilityId Cap { get; private set; }
 
         public string Name
@@ -85,7 +83,7 @@ namespace Sample.WPF
             {
                 if (Cap > CapabilityId.CustomBase)
                 {
-                    return "[Custom] " + ((int)Cap - (int)CapabilityId.CustomBase);
+                    return "[CustomBase]+" + ((int)Cap - (int)CapabilityId.CustomBase);
                 }
                 return Cap.ToString();
             }

samples/Sample.WPF/ViewModels/DataSourceVM.cs

@@ -1,11 +1,19 @@
 using GalaSoft.MvvmLight;
+using GalaSoft.MvvmLight.Command;
+using GalaSoft.MvvmLight.Messaging;
+using ModernWpf.Messages;
 using NTwain;
 using NTwain.Data;
+using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.ComponentModel;
+using System.Diagnostics;
+using System.IO;
 using System.Linq;
+using System.Text;
 using System.Windows.Data;
+using System.Windows.Input;
 
 namespace Sample.WPF
 {
@@ -69,5 +77,55 @@ namespace Sample.WPF
         }
 
         public ObservableCollection<CapVM> Caps { get; private set; }
+
+        private ICommand _saveCapCommand;
+
+        public ICommand SaveCapValuesCommand
+        {
+            get
+            {
+                return _saveCapCommand ?? (_saveCapCommand = new RelayCommand(() =>
+                {
+                    Messenger.Default.Send(new ChooseFileMessage(files =>
+                    {
+                        StringBuilder report = new StringBuilder();
+                        report.Append("Cap values for TWAIN device ").AppendLine(DS.Name);
+                        report.Append("Generated on ").AppendLine(DateTime.Now.ToString("yyyy/MM/dd hh:mm tt")).AppendLine();
+
+                        foreach (CapVM cap in _capView)
+                        {
+                            report.Append(cap.Name).AppendLine(":");
+                            try
+                            {
+                                report.Append('\t').Append("Maybe: ").Append(cap.Supports).AppendLine();
+                                report.Append('\t').Append("Get: ");
+                                foreach (var v in cap.Get())
+                                {
+                                    report.Append(v).Append(',');
+                                }
+                                report.AppendLine();
+                                report.Append('\t').Append("Current: ").Append(cap.GetCurrent()).AppendLine();
+                            }
+                            catch (Exception ex)
+                            {
+                                report.Append('\t').Append("Failed: ").Append(ex.Message).AppendLine();
+                            }
+                            report.AppendLine();
+                        }
+
+                        File.WriteAllText(files.First(), report.ToString());
+
+                        using (Process.Start(files.First())) { }
+                    })
+                    {
+                        Caption = "Choose Save File",
+                        Filters = "Text files|*.txt",
+                        InitialFileName = DS.Name + " capability",
+                        Purpose = FilePurpose.Save,
+                    });
+                }, () => DS.IsOpen));
+            }
+        }
+
     }
 }

src/NTwain/CapWrapper.cs

@@ -1,6 +1,7 @@
 using NTwain.Data;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 
@@ -111,7 +112,9 @@ namespace NTwain
             if (!_supports.HasValue && _source.IsOpen)
             {
                 var srcVersion = _source.ProtocolVersion;
-                if (srcVersion >= ProtocolVersions.GetMinimumVersion(Capability))
+                var minVer = ProtocolVersions.GetMinimumVersion(Capability);
+
+                if (srcVersion >= minVer)
                 {
                     _supports = _source.Capabilities.QuerySupport(Capability);
 
@@ -137,6 +140,7 @@ namespace NTwain
                             }
                             else
                             {
+                                Debug.WriteLine("Cap " + Capability + " supports set to None due to rc=" + rc + ", cc=" + _source.GetStatus().ConditionCode);
                                 _supports = QuerySupports.None;
                             }
                         }
@@ -144,6 +148,7 @@ namespace NTwain
                 }
                 else
                 {
+                    Debug.WriteLine("Cap " + Capability + " supports set to None due to not in required TWAIN version (" + minVer + ") not met by source (" + srcVersion + ").");
                     _supports = QuerySupports.None;
                 }
             }

src/NTwain/ICapWrapper.cs

@@ -177,12 +177,13 @@ namespace NTwain
         /// </summary>
         /// <param name="value">The value.</param>
         /// <returns></returns>
-        ReturnCode SetValue(TValue value);/// <summary>
+        ReturnCode SetValue(TValue value);
-                                          /// 
+        
-                                          /// A version of Set that uses an array.
+        /// <summary>
-                                          /// </summary>
+        /// A version of Set that uses an array.
-                                          /// <param name="value">The value.</param>
+        /// </summary>
-                                          /// <returns></returns>
+        /// <param name="value">The value.</param>
+        /// <returns></returns>
         ReturnCode SetValue(TWArray value);
 
         /// <summary>