Add DisplayMemberBinding to ItemsControl

src/Avalonia.Controls/Generators/IItemContainerGenerator.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using Avalonia.Controls.Templates;
+using Avalonia.Data;
 using Avalonia.Styling;
 
 namespace Avalonia.Controls.Generators
@@ -24,6 +25,11 @@ namespace Avalonia.Controls.Generators
         /// Gets or sets the data template used to display the items in the control.
         /// </summary>
         IDataTemplate? ItemTemplate { get; set; }
+        
+        /// <summary>
+        /// Gets or sets the binding to use to bind to the member of an item used for displaying
+        /// </summary>
+        IBinding? DisplayMemberBinding { get; set; }
 
         /// <summary>
         /// Gets the ContainerType, or null if its an untyped ContainerGenerator.

src/Avalonia.Controls/Generators/ItemContainerGenerator.cs

@@ -45,6 +45,9 @@ namespace Avalonia.Controls.Generators
         /// Gets or sets the data template used to display the items in the control.
         /// </summary>
         public IDataTemplate? ItemTemplate { get; set; }
+        
+        /// <inheritdoc />
+        public IBinding? DisplayMemberBinding { get; set; }
 
         /// <summary>
         /// Gets the owner control.
@@ -189,7 +192,15 @@ namespace Avalonia.Controls.Generators
             if (result == null)
             {
                 result = new ContentPresenter();
-                result.SetValue(ContentPresenter.ContentProperty, item, BindingPriority.Style);
+                if (DisplayMemberBinding is not null)
+                {
+                    result.SetValue(StyledElement.DataContextProperty, item, BindingPriority.Style);
+                    result.Bind(ContentPresenter.ContentProperty, DisplayMemberBinding, BindingPriority.Style);
+                }
+                else
+                {
+                    result.SetValue(ContentPresenter.ContentProperty, item, BindingPriority.Style);
+                }
 
                 if (ItemTemplate != null)
                 {

src/Avalonia.Controls/Generators/ItemContainerGenerator`1.cs

@@ -53,8 +53,16 @@ namespace Avalonia.Controls.Generators
                     container.SetValue(ContentTemplateProperty, ItemTemplate, BindingPriority.Style);
                 }
 
-                container.SetValue(ContentProperty, item, BindingPriority.Style);
-
+                if (DisplayMemberBinding is not null)
+                {
+                    container.SetValue(StyledElement.DataContextProperty, item, BindingPriority.Style);
+                    container.Bind(ContentProperty, DisplayMemberBinding, BindingPriority.Style);
+                }
+                else
+                {
+                    container.SetValue(ContentProperty, item, BindingPriority.Style);
+                }
+                
                 if (!(item is IControl))
                 {
                     container.DataContext = item;

src/Avalonia.Controls/Generators/TreeItemContainerGenerator.cs

@@ -76,7 +76,15 @@ namespace Avalonia.Controls.Generators
                     result.SetValue(Control.ThemeProperty, ItemContainerTheme, BindingPriority.Style);
                 }
 
-                result.SetValue(ContentProperty, template.Build(item), BindingPriority.Style);
+                if (DisplayMemberBinding is not null)
+                {
+                    result.SetValue(StyledElement.DataContextProperty, item, BindingPriority.Style);
+                    result.Bind(ContentProperty, DisplayMemberBinding, BindingPriority.Style);
+                }
+                else
+                {
+                    result.SetValue(ContentProperty, item, BindingPriority.Style);
+                }
 
                 var itemsSelector = template.ItemsSelector(item);
 

src/Avalonia.Controls/ItemsControl.cs

@@ -11,6 +11,7 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Controls.Utils;
+using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.LogicalTree;
 using Avalonia.Metadata;
@@ -61,6 +62,23 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<IDataTemplate?> ItemTemplateProperty =
             AvaloniaProperty.Register<ItemsControl, IDataTemplate?>(nameof(ItemTemplate));
 
+
+        /// <summary>
+        /// Defines the <see cref="DisplayMemberBinding" /> property
+        /// </summary>
+        public static readonly StyledProperty<IBinding?> DisplayMemberBindingProperty =
+            AvaloniaProperty.Register<ItemsControl, IBinding?>(nameof(DisplayMemberBinding));
+
+        /// <summary>
+        /// Gets or sets the <see cref="IBinding"/> to use for binding to the display member of each item.
+        /// </summary>
+        [AssignBinding]
+        public IBinding? DisplayMemberBinding
+        {
+            get { return GetValue(DisplayMemberBindingProperty); }
+            set { SetValue(DisplayMemberBindingProperty, value); }
+        }
+        
         private IEnumerable? _items = new AvaloniaList<object>();
         private int _itemCount;
         private IItemContainerGenerator? _itemContainerGenerator;
@@ -97,6 +115,7 @@ namespace Avalonia.Controls
 
                     _itemContainerGenerator.ItemContainerTheme = ItemContainerTheme;
                     _itemContainerGenerator.ItemTemplate = ItemTemplate;
+                    _itemContainerGenerator.DisplayMemberBinding = DisplayMemberBinding;
                     _itemContainerGenerator.Materialized += (_, e) => OnContainersMaterialized(e);
                     _itemContainerGenerator.Dematerialized += (_, e) => OnContainersDematerialized(e);
                     _itemContainerGenerator.Recycled += (_, e) => OnContainersRecycled(e);

src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs

@@ -5,6 +5,7 @@ using Avalonia.Collections;
 using Avalonia.Controls.Generators;
 using Avalonia.Controls.Templates;
 using Avalonia.Controls.Utils;
+using Avalonia.Data;
 using Avalonia.LogicalTree;
 using Avalonia.Styling;
 
@@ -33,6 +34,12 @@ namespace Avalonia.Controls.Presenters
         public static readonly StyledProperty<IDataTemplate?> ItemTemplateProperty =
             ItemsControl.ItemTemplateProperty.AddOwner<ItemsPresenterBase>();
 
+        /// <summary>
+        /// Defines the <see cref="DisplayMemberBinding" /> property
+        /// </summary>
+        public static readonly StyledProperty<IBinding?> DisplayMemberBindingProperty =
+            ItemsControl.DisplayMemberBindingProperty.AddOwner<ItemsPresenterBase>();
+        
         private IEnumerable? _items;
         private IDisposable? _itemsSubscription;
         private bool _createdPanel;
@@ -120,6 +127,15 @@ namespace Avalonia.Controls.Presenters
             set { SetValue(ItemTemplateProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the <see cref="IBinding"/> to use for binding to the display member of each item.
+        /// </summary>
+        public IBinding? DisplayMemberBinding
+        {
+            get { return GetValue(DisplayMemberBindingProperty); }
+            set { SetValue(DisplayMemberBindingProperty, value); }
+        }
+
         /// <summary>
         /// Gets the panel used to display the items.
         /// </summary>
@@ -177,6 +193,7 @@ namespace Avalonia.Controls.Presenters
             {
                 result = new ItemContainerGenerator(this);
                 result.ItemTemplate = ItemTemplate;
+                result.DisplayMemberBinding = DisplayMemberBinding;
             }
 
             result.Materialized += ContainerActionHandler;