fix(itemscontrol): Bind DisplayMemberPath target

Apply a binding rather than a one-time set to the property targeted by DisplayMemberPath. This ensures items update correctly if the property value should change.

src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_ListViewBase.cs

@@ -1350,6 +1350,35 @@ public async Task When_Selection_Events()
 			list.SelectedIndex = 1;
 		}
 
+		[TestMethod]
+		public async Task When_DisplayMemberPath_Property_Changed()
+		{
+			var itemsSource = (new[] { "aaa", "bbb", "ccc", "ddd" }).Select(s => new When_DisplayMemberPath_Property_Changed_DataContext { Display = s }).ToArray();
+
+			var SUT = new ListView()
+			{
+				ItemContainerStyle = BasicContainerStyle,
+				DisplayMemberPath = "Display",
+				ItemsSource = itemsSource
+			};
+
+			WindowHelper.WindowContent = SUT;
+			await WindowHelper.WaitForLoaded(SUT);
+
+			var secondContainer = await WindowHelper.WaitForNonNull(() => SUT.ContainerFromIndex(1) as ListViewItem);
+			await WindowHelper.WaitForLoaded(secondContainer);
+
+			var tb = secondContainer.FindFirstChild<TextBlock>();
+			Assert.AreEqual("bbb", tb.Text);
+
+			foreach (var item in itemsSource)
+			{
+				item.Display = item.Display.ToUpperInvariant();
+			}
+
+			await WindowHelper.WaitForResultEqual("BBB", () => tb.Text);
+		}
+
 		private bool ApproxEquals(double value1, double value2) => Math.Abs(value1 - value2) <= 2;
 
 		private class When_Removed_From_Tree_And_Selection_TwoWay_Bound_DataContext : global::System.ComponentModel.INotifyPropertyChanged
@@ -1413,6 +1442,26 @@ protected void RaiseAndSetIfChanged<T>(ref T backingField, T value, [CallerMembe
 				}
 			}
 		}
+
+		private class When_DisplayMemberPath_Property_Changed_DataContext : INotifyPropertyChanged
+		{
+			private string _display;
+
+			public event PropertyChangedEventHandler PropertyChanged;
+
+			public string Display
+			{
+				get => _display;
+				set
+				{
+					if (value != _display)
+					{
+						_display = value;
+						PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Display)));
+					}
+				}
+			}
+		}
 	}
 
 	public partial class OnItemsChangedListView : ListView

src/Uno.UI/UI/Xaml/Controls/ItemsControl/ItemsControl.cs

@@ -1046,18 +1046,20 @@ protected virtual void PrepareContainerForItemOverride(DependencyObject element,
 
 			var styleFromItemsControl = ItemContainerStyle ?? ItemContainerStyleSelector?.SelectStyle(item, element);
 
-			object GetContent()
+			void SetContent(UIElement container, DependencyProperty contentProperty)
 			{
 				var displayMemberPath = DisplayMemberPath;
 				if (string.IsNullOrEmpty(displayMemberPath))
 				{
-					return item;
+					container.SetValue(contentProperty, item);
 				}
 				else
 				{
-					// TODO: Cache the BindingPath
-					var b = new BindingPath(displayMemberPath, item) { DataContext = item };
-					return b.Value;
+					container.SetBinding(contentProperty, new Binding
+					{
+						Path = displayMemberPath,
+						Source = item
+					});
 				}
 			}
 
@@ -1078,7 +1080,7 @@ object GetContent()
 
 				if (!isOwnContainer)
 				{
-					containerAsContentPresenter.Content = GetContent();
+					SetContent(containerAsContentPresenter, ContentPresenter.ContentProperty);
 				}
 			}
 			else if (element is ContentControl containerAsContentControl)
@@ -1101,7 +1103,7 @@ object GetContent()
 					// Set the datacontext first, then the binding.
 					// This avoids the inner content to go through a partial content being
 					// the result of the fallback value of the binding set below.
-					containerAsContentControl.DataContext = GetContent();
+					SetContent(containerAsContentControl, ContentControl.DataContextProperty);
 
 					if (!containerAsContentControl.IsContainerFromTemplateRoot && containerAsContentControl.GetBindingExpression(ContentControl.ContentProperty) == null)
 					{