Merge pull request #558 from l1pton17/ComboBoxClassicModeShowSelectedItem

ComboBox tweaks

Author: ButchersBoy

MainDemo.Wpf/TextFields.xaml

@@ -62,6 +62,8 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
         <TextBlock Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2" Style="{StaticResource MaterialDesignHeadlineTextBlock}">Common Fields</TextBlock>
         <materialDesign:PackIcon Grid.Row="1" Grid.Column="0" Kind="Account" Foreground="{Binding ElementName=NameTextBox, Path=BorderBrush}" />
@@ -262,6 +264,7 @@
         </TextBox>
         <CheckBox Grid.Row="9" Grid.Column="4"
                   x:Name="DisplaySelectedItemCheckBox"
+                  IsThreeState="False"
                   Margin="0 8 0 0">Display Selected Item In Drop Down</CheckBox>
         <ComboBox Grid.Row="10" Grid.Column="4" 
                   materialDesign:ComboBoxAssist.ShowSelectedItem="{Binding ElementName=DisplaySelectedItemCheckBox, Path=IsChecked}"
@@ -271,6 +274,18 @@
             <ComboBoxItem>Pear</ComboBoxItem>
             <ComboBoxItem>Orange</ComboBoxItem>
         </ComboBox>
+        <CheckBox Grid.Row="11" Grid.Column="4"
+                  x:Name="ClassicModeCheckBox"
+                  IsThreeState="False" IsChecked="True"
+                  Margin="0 8 0 0">Use classic mode</CheckBox>
+        <ComboBox Grid.Row="12" Grid.Column="4" 
+                  materialDesign:ComboBoxAssist.ClassicMode="{Binding ElementName=ClassicModeCheckBox, Path=IsChecked}"
+                  Margin="0 8 0 8" HorizontalAlignment="Left">
+            <ComboBoxItem IsSelected="True">Apple</ComboBoxItem>
+            <ComboBoxItem>Banana</ComboBoxItem>
+            <ComboBoxItem>Pear</ComboBoxItem>
+            <ComboBoxItem>Orange</ComboBoxItem>
+        </ComboBox>
 
     </Grid>
 </UserControl>

MaterialDesignThemes.Wpf/ComboBoxAssist.cs

@@ -11,7 +11,27 @@ namespace MaterialDesignThemes.Wpf
     public static class ComboBoxAssist
     {
         /// <summary>
-        /// By default the selected item his hidden from the drop down list, as per Material Design specifications. 
+        /// By default ComboBox uses the wrapper popup. Popup can be switched to classic Windows desktop view by means of this attached property.
+        /// </summary>
+        public static readonly DependencyProperty ClassicModeProperty = DependencyProperty.RegisterAttached(
+            "ClassicMode",
+            typeof (bool),
+            typeof (ComboBoxAssist),
+            new FrameworkPropertyMetadata(false,
+                FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.Inherits));
+
+        public static bool GetClassicMode(DependencyObject element, object value)
+        {
+            return (bool)element.GetValue(ClassicModeProperty);
+        }
+
+        public static void SetClassicMode(DependencyObject element, object value)
+        {
+            element.SetValue(ClassicModeProperty, value);
+        }
+
+        /// <summary>
+        /// By default the selected item is hidden from the drop down list, as per Material Design specifications. 
         /// To revert to a more classic Windows desktop behaviour, and show the currently selected item again in the drop
         /// down, set this attached propety to true.
         /// </summary>