Все ComboBox доведены до ума.

eCompanies/App.xaml.cs

@@ -1,12 +1,8 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Configuration;
 using System.Data;
 using System.Linq;
-using System.Threading.Tasks;
 using System.Windows;
-using System.Windows.Navigation;
 
 namespace eCompanies
 {

eCompanies/Contract.cs

@@ -1,12 +1,18 @@
-using System;
+using System.ComponentModel;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace eCompanies
 {
-    public enum Status { NotReachedYet, Reached, Terminated }
+    [TypeConverter(typeof(EnumDescriptionTypeConverter))]
+    public enum Status
+    {
+        [Description("Еще не заключен")]
+        NotReachedYet,
+        [Description("Заключен")]
+        Reached,
+        [Description("Расторгнут")]
+        Terminated
+    }
+
     public class Contract
     {
         private Companies c;

eCompanies/EnumBindingSourceExtension.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Windows.Markup;
+
+namespace eCompanies
+{
+    public class EnumBindingSourceExtension : MarkupExtension
+    {
+        private Type _enumType;
+        public Type EnumType
+        {
+            get { return this._enumType; }
+            set
+            {
+                if (value != this._enumType)
+                {
+                    if (null != value)
+                    {
+                        Type enumType = Nullable.GetUnderlyingType(value) ?? value;
+
+                        if (!enumType.IsEnum)
+                            throw new ArgumentException("Type must be for an Enum.");
+                    }
+
+                    this._enumType = value;
+                }
+            }
+        }
+
+        public EnumBindingSourceExtension() { }
+
+        public EnumBindingSourceExtension(Type enumType)
+        {
+            this.EnumType = enumType;
+        }
+
+        public override object ProvideValue(IServiceProvider serviceProvider)
+        {
+            if (null == this._enumType)
+                throw new InvalidOperationException("The EnumType must be specified.");
+
+            Type actualEnumType = Nullable.GetUnderlyingType(this._enumType) ?? this._enumType;
+            Array enumValues = Enum.GetValues(actualEnumType);
+
+            if (actualEnumType == this._enumType)
+                return enumValues;
+
+            Array tempArray = Array.CreateInstance(actualEnumType, enumValues.Length + 1);
+            enumValues.CopyTo(tempArray, 1);
+            return tempArray;
+        }
+    }
+}

eCompanies/EnumDescriptoionTypeConverter.cs

@@ -0,0 +1,34 @@
+using System;
+using System.ComponentModel;
+using System.Reflection;
+
+namespace eCompanies
+{
+    public class EnumDescriptionTypeConverter : EnumConverter
+    {
+        public EnumDescriptionTypeConverter(Type type)
+            : base(type)
+        {
+        }
+
+        public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
+        {
+            if (destinationType == typeof(string))
+            {
+                if (value != null)
+                {
+                    FieldInfo fi = value.GetType().GetField(value.ToString());
+                    if (fi != null)
+                    {
+                        var attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
+                        return ((attributes.Length > 0) && (!String.IsNullOrEmpty(attributes[0].Description))) ? attributes[0].Description : value.ToString();
+                    }
+                }
+
+                return string.Empty;
+            }
+
+            return base.ConvertTo(context, culture, value, destinationType);
+        }
+    }
+}

eCompanies/MainWindow.xaml

@@ -4,17 +4,8 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:eCompanies"
-        xmlns:core="clr-namespace:System;assembly=mscorlib"
-        xmlns:col="clr-namespace:System.Collections;assembly=mscorlib"
         mc:Ignorable="d"
         Title="MainWindow" Height="450" Width="800">
-    <Window.Resources>
-        <ObjectDataProvider x:Key="Status" MethodName="GetValues" ObjectType="{x:Type core:Enum}">
-            <ObjectDataProvider.MethodParameters>
-                <x:Type Type="local:Status"/>
-            </ObjectDataProvider.MethodParameters>
-        </ObjectDataProvider>
-    </Window.Resources>
     <Grid>  
         <DataGrid x:Name="companyGrid" HorizontalAlignment="Left" Height="354" Margin="10,55,0,0" VerticalAlignment="Top" Width="772" ItemsSource="{Binding}" AutoGenerateColumns="False" MouseDoubleClick="companyGrid_MouseDoubleClick">
             <DataGrid.Columns>
@@ -22,7 +13,7 @@
                 <DataGridTextColumn Header="Название компании" Binding="{Binding Name}" Width="*"/>
                 <DataGridComboBoxColumn x:Name="ContractComboBox"  Header="Состояние контракта" 
                                         SelectedValueBinding="{Binding Path=contract.ContractStatusId}" 
-                                        ItemsSource="{Binding Source={StaticResource Status}}">
+                                        ItemsSource="{Binding Source={local:EnumBindingSource {x:Type local:Status}}}">
                 </DataGridComboBoxColumn>
             </DataGrid.Columns>
         </DataGrid>

eCompanies/UsersWindow.xaml

@@ -20,10 +20,7 @@
             </DataGrid.Columns>
         </DataGrid>
         <TextBox x:Name="companyNameBox" HorizontalAlignment="Left" Height="40" Margin="10,10,0,0" TextWrapping="Wrap" Text="none" VerticalAlignment="Top" Width="470" FontSize="22"/>
-        <ComboBox x:Name="contractStatusComboBox" HorizontalAlignment="Left" Height="40" Margin="490,10,0,0" VerticalAlignment="Top" Width="292" FontSize="22">
+        <ComboBox x:Name="contractStatusComboBox" HorizontalAlignment="Left" Height="40" Margin="490,10,0,0" VerticalAlignment="Top" Width="292" FontSize="22" ItemsSource="{Binding Source={local:EnumBindingSource {x:Type local:Status}}}">
-            <ComboBoxItem>Еще не заключен</ComboBoxItem>
-            <ComboBoxItem>Заключен</ComboBoxItem>
-            <ComboBoxItem>Расторгнут</ComboBoxItem>
         </ComboBox>
     </Grid>
 </Window>

eCompanies/eCompanies.csproj

@@ -140,6 +140,8 @@
     </ApplicationDefinition>
     <Compile Include="CompaniesDBContext.cs" />
     <Compile Include="Contract.cs" />
+    <Compile Include="EnumBindingSourceExtension.cs" />
+    <Compile Include="EnumDescriptoionTypeConverter.cs" />
     <Compile Include="Users.cs" />
     <Compile Include="UsersWindow.xaml.cs">
       <DependentUpon>UsersWindow.xaml</DependentUpon>