styled element and application implement IDataContext.

src/Avalonia.Controls/Application.cs

@@ -32,7 +32,7 @@ namespace Avalonia
     /// method.
     /// - Tracks the lifetime of the application.
     /// </remarks>
-    public class Application : AvaloniaObject, IGlobalDataTemplates, IGlobalStyles, IStyleRoot, IResourceNode
+    public class Application : AvaloniaObject, IDataContext, IGlobalDataTemplates, IGlobalStyles, IStyleRoot, IResourceNode
     {
         /// <summary>
         /// The application-global data templates.
@@ -45,6 +45,13 @@ namespace Avalonia
         private Styles _styles;
         private IResourceDictionary _resources;
 
+        /// <summary>
+        /// Defines the <see cref="DataContext"/> property.
+        /// </summary>
+        public static readonly StyledProperty<object> DataContextProperty =
+            AvaloniaProperty.Register<Application, object>(
+                nameof(DataContext));
+
         /// <inheritdoc/>
         public event EventHandler<ResourcesChangedEventArgs> ResourcesChanged;
 
@@ -56,6 +63,19 @@ namespace Avalonia
             Name = "Avalonia Application";
         }
 
+        /// <summary>
+        /// Gets or sets the Applications's data context.
+        /// </summary>
+        /// <remarks>
+        /// The data context property specifies the default object that will
+        /// be used for data binding.
+        /// </remarks>
+        public object DataContext
+        {
+            get { return GetValue(DataContextProperty); }
+            set { SetValue(DataContextProperty, value); }
+        }
+
         /// <summary>
         /// Gets the current instance of the <see cref="Application"/> class.
         /// </summary>

src/Avalonia.Styling/StyledElement.cs

@@ -24,7 +24,7 @@ namespace Avalonia
     /// - Implements <see cref="ILogical"/> to form part of a logical tree.
     /// - A collection of class strings for custom styling.
     /// </summary>
-    public class StyledElement : Animatable, IStyledElement, ISetLogicalParent, ISetInheritanceParent
+    public class StyledElement : Animatable, IDataContext, IStyledElement, ISetLogicalParent, ISetInheritanceParent
     {
         /// <summary>
         /// Defines the <see cref="DataContext"/> property.