improve combos in grids...not quite there yet, but closer...

Author: ButchersBoy

MaterialDesignColors.WpfExample/Domain/ListFieldsViewModel.cs

@@ -58,7 +58,8 @@ private static ObservableCollection<SelectableViewModel> CreateData()
                 {
                     Code = 'D',
                     Name = "Dragablz",
-                    Description = "Dragablz Tab Control"
+                    Description = "Dragablz Tab Control",
+                    Food = "Fries"
                 },
                 new SelectableViewModel
                 {
@@ -92,5 +93,16 @@ protected virtual void OnPropertyChanged([CallerMemberName] string propertyName
                 PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
             //PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
+
+        public IEnumerable<string> Foods
+        {
+            get
+            {
+                yield return "Burger";
+                yield return "Fries";
+                yield return "Shake";
+                yield return "Lettuce";
+            }            
+        }
     }
 }

MaterialDesignColors.WpfExample/Domain/SelectableViewModel.cs

@@ -4,13 +4,15 @@
 
 namespace MaterialDesignColors.WpfExample.Domain
 {
+    
     public class SelectableViewModel : INotifyPropertyChanged
     {
         private bool _isSelected;
         private string _name;
         private string _description;
         private char _code;
-        private double _numeric;        
+        private double _numeric;
+        private string _food;
 
         public bool IsSelected
         {
@@ -65,7 +67,18 @@ public double Numeric
                 _numeric = value;
                 OnPropertyChanged();
             }
-        }        
+        }
+
+        public string Food
+        {
+            get { return _food; }
+            set
+            {
+                if (_food == value) return;
+                _food = value;
+                OnPropertyChanged();
+            }
+        }
 
         public event PropertyChangedEventHandler PropertyChanged;
 

MaterialDesignColors.WpfExample/ListsWindow.xaml

@@ -131,6 +131,11 @@
                                 </Style>
                             </DataGridTextColumn.ElementStyle>    
                         </wpf:MaterialDataGridTextColumn>
+
+                        <!-- use custom combo box column to get better combos. Use ItemsSourceBinding as your binding template to be applied to each combo -->
+                        <wpf:MaterialDataGridComboBoxColumn Header="Food"        
+                                                            SelectedValueBinding="{Binding Food}"                                                            
+                                                            ItemsSourceBinding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}, Path=DataContext.Foods}" />
                     </DataGrid.Columns>
                 </DataGrid>
             </TabItem>

MaterialDesignThemes.Wpf/DataGridAssist.cs

@@ -78,6 +78,6 @@ public static void SetAutoGeneratedEditingTextStyle(DependencyObject element, St
         public static Style GetAutoGeneratedEditingTextStyle(DependencyObject element)
         {
             return (Style) element.GetValue(AutoGeneratedEditingTextStyleProperty);
-        }
+        }        
     }
 }

MaterialDesignThemes.Wpf/MaterialDataGridComboBoxColumn.cs

@@ -0,0 +1,104 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+
+namespace MaterialDesignThemes.Wpf
+{
+    public class MaterialDataGridComboBoxColumn : DataGridComboBoxColumn //DataGridBoundColumn
+    {
+        static MaterialDataGridComboBoxColumn()
+        {            
+            ElementStyleProperty.OverrideMetadata(typeof(MaterialDataGridComboBoxColumn), new FrameworkPropertyMetadata(DefaultElementStyle));
+            EditingElementStyleProperty.OverrideMetadata(typeof(MaterialDataGridComboBoxColumn), new FrameworkPropertyMetadata(DefaultEditingElementStyle));
+        }
+
+        public Binding ItemsSourceBinding { get; set; }
+
+        protected override FrameworkElement GenerateElement(DataGridCell cell, object dataItem)
+        {
+            var comboBox = base.GenerateElement(cell, cell);
+
+            if (ItemsSourceBinding != null)
+                comboBox.SetBinding(ItemsControl.ItemsSourceProperty, ItemsSourceBinding);
+            ApplyStyle(false, false, comboBox);                       
+
+            return comboBox;
+        }
+
+        protected override FrameworkElement GenerateEditingElement(DataGridCell cell, object dataItem)
+        {
+            var comboBox = (ComboBox)base.GenerateElement(cell, cell);
+
+            if (ItemsSourceBinding != null)
+                comboBox.SetBinding(ItemsControl.ItemsSourceProperty, ItemsSourceBinding);            
+            ApplyStyle(true, false, comboBox);            
+
+            return comboBox;
+        }
+
+        public static new Style DefaultElementStyle
+        {
+            get
+            {
+                var comboBox = new ComboBox();
+
+                var brushKey = new ComponentResourceKey(typeof(ComboBox), "MaterialDataGridComboBoxColumnStyle");
+                var style = (Style)comboBox.TryFindResource(brushKey);
+
+                return style;
+            }
+        }
+
+        public static new Style DefaultEditingElementStyle
+        {
+            get
+            {
+                var comboBox = new ComboBox();
+
+                var brushKey = new ComponentResourceKey(typeof(ComboBox), "MaterialDataGridComboBoxColumnEditingStyle");
+                var style = (Style)comboBox.TryFindResource(brushKey);
+
+                return style;
+            }
+        }
+        
+        private void ApplyStyle(bool isEditing, bool defaultToElementStyle, FrameworkElement element)
+        {
+            var style = PickStyle(isEditing, defaultToElementStyle);
+            if (style != null)
+            {
+                element.Style = style;
+            }
+        }
+
+        private Style PickStyle(bool isEditing, bool defaultToElementStyle)
+        {
+            var style = isEditing ? EditingElementStyle : ElementStyle;
+            if (isEditing && defaultToElementStyle && (style == null))
+            {
+                style = ElementStyle;
+            }
+
+            return style;
+        }
+
+        /*
+        /// <summary>
+        ///     Assigns the Binding to the desired property on the target object.
+        /// </summary>
+        private void ApplyBinding(DependencyObject target, DependencyProperty property)
+        {
+            var binding = Binding;
+            if (binding != null)
+            {
+                BindingOperations.SetBinding(target, property, binding);
+            }
+            else
+            {
+                BindingOperations.ClearBinding(target, property);
+            }
+        }
+        */
+
+    }
+}

MaterialDesignThemes.Wpf/MaterialDesignThemes.Wpf.csproj

@@ -80,6 +80,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="Themes\MaterialDesignTheme.DataGrid.ComboBox.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="Themes\MaterialDesignTheme.DataGrid.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -165,6 +169,7 @@
     <Compile Include="DataGridAssist.cs" />
     <Compile Include="DateTimeEx.cs" />
     <Compile Include="ListSortDirectionIndicator.cs" />
+    <Compile Include="MaterialDataGridComboBoxColumn.cs" />
     <Compile Include="MaterialDataGridTextColumn.cs" />
     <Compile Include="MaterialDateDisplay.cs" />
     <Compile Include="PaletteHelper.cs" />