The fix for child FlexLayout content appearing no longer works starting from version 8.0.61

src/Controls/src/Core/Layout/FlexLayout.cs

@@ -495,16 +495,16 @@ void AddFlexItem(int index, IView child)
 			InitItemProperties(child, item);
 			if (child is not FlexLayout)
 			{
-				item.SelfSizing = (Flex.Item it, ref float w, ref float h) =>
+				item.SelfSizing = (Flex.Item it, ref float w, ref float h, bool inMeasureMode) =>
 				{
 					Size request;
 
-					if (InMeasureMode)
+					if (inMeasureMode)
 					{
 						var sizeConstraints = item.GetConstraints();
 
-						sizeConstraints.Width = (InMeasureMode && sizeConstraints.Width == 0) ? double.PositiveInfinity : sizeConstraints.Width;
-						sizeConstraints.Height = (InMeasureMode && sizeConstraints.Height == 0) ? double.PositiveInfinity : sizeConstraints.Height;
+						sizeConstraints.Width = (inMeasureMode && sizeConstraints.Width == 0) ? double.PositiveInfinity : sizeConstraints.Width;
+						sizeConstraints.Height = (inMeasureMode && sizeConstraints.Height == 0) ? double.PositiveInfinity : sizeConstraints.Height;
 
 						if (child is Image)
 						{
@@ -585,7 +585,7 @@ public void Layout(double width, double height)
 
 			_root.Width = !double.IsPositiveInfinity((width)) ? (float)width : 0;
 			_root.Height = !double.IsPositiveInfinity((height)) ? (float)height : 0;
-			_root.Layout();
+			_root.Layout(InMeasureMode);
 
 			if (useMeasureHack)
 			{

src/Controls/src/Core/LegacyLayouts/FlexLayout.cs

@@ -306,11 +306,11 @@ void AddChild(View view)
 			InitItemProperties(view, item);
 			if (!(view is FlexLayout))
 			{ //inner layouts don't get measured
-				item.SelfSizing = (Flex.Item it, ref float w, ref float h) =>
+				item.SelfSizing = (Flex.Item it, ref float w, ref float h, bool inMeasureMode) =>
 				{
 					var sizeConstrains = item.GetConstraints();
-					sizeConstrains.Width = (_measuring && sizeConstrains.Width == 0) ? double.PositiveInfinity : sizeConstrains.Width;
-					sizeConstrains.Height = (_measuring && sizeConstrains.Height == 0) ? double.PositiveInfinity : sizeConstrains.Height;
+					sizeConstrains.Width = (inMeasureMode && sizeConstrains.Width == 0) ? double.PositiveInfinity : sizeConstrains.Width;
+					sizeConstrains.Height = (inMeasureMode && sizeConstrains.Height == 0) ? double.PositiveInfinity : sizeConstrains.Height;
 					var request = view.Measure(sizeConstrains.Width, sizeConstrains.Height, MeasureFlags.None).Request;
 					w = (float)request.Width;
 					h = (float)request.Height;
@@ -489,7 +489,7 @@ void Layout(double width, double height)
 				return;
 			_root.Width = !double.IsPositiveInfinity((width)) ? (float)width : 0;
 			_root.Height = !double.IsPositiveInfinity((height)) ? (float)height : 0;
-			_root.Layout();
+			_root.Layout(_measuring);
 		}
 	}
 }

src/Controls/tests/TestCases.HostApp/Issues/Issue23491.cs

@@ -0,0 +1,49 @@
+using Microsoft.Maui.Layouts;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 23491, "BindableLayout.ItemsSource no longer works in 8.0.61", PlatformAffected.All)]
+	public class Issue23491 : ContentPage
+	{
+		Label headerLabel;
+		Label label1;
+		Label label2;
+		public Issue23491()
+		{
+			headerLabel = new Label { Text = "Below is the Content of the Child FlexLayout",
+			TextColor=Colors.Red };
+
+			headerLabel.AutomationId = "HeaderLabel";
+
+            // Child FlexLayout
+            label1 = new Label
+            {
+                Text = "First label inside the child flexlayout",
+				Padding =new Thickness(5)
+            };
+
+            label2 = new Label
+            {
+                Text = "Second label inside the child flexLayout",
+				Padding =new Thickness(5)
+            };
+
+            var childFlexLayout = new FlexLayout
+            {
+                Margin = new Thickness(10),
+                Wrap = FlexWrap.Wrap,
+                Children = { label1, label2 }
+            };
+
+            // Main FlexLayout
+            var mainLayout = new FlexLayout
+            {
+                Direction = FlexDirection.Column,
+				Children = { headerLabel, childFlexLayout }
+            };
+
+            // Set the content of the page
+            Content = mainLayout;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue23491.cs

@@ -0,0 +1,21 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue23491 : _IssuesUITest
+	{
+		public Issue23491(TestDevice device) : base(device) { }
+
+		public override string Issue => "BindableLayout.ItemsSource no longer works in 8.0.61";
+
+		[Test]
+		[Category(UITestCategories.Label)]
+		public void ChildFlexLayoutContentShouldAppear()
+		{
+			App.WaitForElement("HeaderLabel");
+			VerifyScreenshot();
+		}
+	}
+}

src/Core/src/Layouts/Flex.cs

@@ -426,18 +426,18 @@ public Item Root
 			}
 		}
 
-		public void Layout()
+		public void Layout(bool inMeasureMode)
 		{
 			if (Parent != null)
 				throw new InvalidOperationException("Layout() must be called on a root item (that hasn't been added to another item)");
 			if (Double.IsNaN(Width) || Double.IsNaN(Height))
 				throw new InvalidOperationException("Layout() must be called on an item that has proper values for the Width and Height properties");
 			if (SelfSizing != null)
 				throw new InvalidOperationException("Layout() cannot be called on an item that has the SelfSizing property set");
-			layout_item(this, Width, Height);
+			layout_item(this, Width, Height, inMeasureMode);
 		}
 
-		public delegate void SelfSizingDelegate(Item item, ref float width, ref float height);
+		public delegate void SelfSizingDelegate(Item item, ref float width, ref float height, bool inMeasureMode);
 
 		public SelfSizingDelegate? SelfSizing { get; set; }
 
@@ -449,7 +449,7 @@ void ValidateChild(Item child)
 				throw new ArgumentException("child already has a parent");
 		}
 
-		static void layout_item(Item item, float width, float height)
+		static void layout_item(Item item, float width, float height, bool inMeasureMode)
 		{
 			if (item == null || item.Count == 0)
 				return;
@@ -476,7 +476,7 @@ static void layout_item(Item item, float width, float height)
 					child.Frame[1] = absolute_pos(child.Top, child.Bottom, child.Frame[3], height);
 
 					// Now that the item has a frame, we can layout its children.
-					layout_item(child, child.Frame[2], child.Frame[3]);
+					layout_item(child, child.Frame[2], child.Frame[3], inMeasureMode);
 					continue;
 				}
 
@@ -507,7 +507,7 @@ static void layout_item(Item item, float width, float height)
 				{
 					float[] size = { child.Frame[2], child.Frame[3] };
 
-					child.SelfSizing(child, ref size[0], ref size[1]);
+					child.SelfSizing(child, ref size[0], ref size[1], inMeasureMode);
 
 					for (int j = 0; j < 2; j++)
 					{
@@ -540,7 +540,7 @@ static void layout_item(Item item, float width, float height)
 					{
 						// Not enough space for this child on this line, layout the
 						// remaining items and move it to a new line.
-						layout_items(item, last_layout_child, i, relative_children_count, ref layout);
+						layout_items(item, last_layout_child, i, relative_children_count, ref layout, inMeasureMode);
 
 						layout.reset();
 						last_layout_child = i;
@@ -578,7 +578,7 @@ static void layout_item(Item item, float width, float height)
 			}
 
 			// Layout remaining items in wrap mode, or everything otherwise.
-			layout_items(item, last_layout_child, item.Count, relative_children_count, ref layout);
+			layout_items(item, last_layout_child, item.Count, relative_children_count, ref layout, inMeasureMode);
 
 			// In wrap mode we may need to tweak the position of each line according to
 			// the align_content property as well as the cross-axis size of items that
@@ -729,7 +729,7 @@ static void layout_align(AlignContent align, float flex_dim, uint children_count
 			}
 		}
 
-		static void layout_items(Item item, int child_begin, int child_end, int children_count, ref flex_layout layout)
+		static void layout_items(Item item, int child_begin, int child_end, int children_count, ref flex_layout layout, bool inMeasureMode)
 		{
 			if (children_count > (child_end - child_begin))
 				throw new ArgumentException($"The {children_count} must not be smaller than the requested range between {child_begin} and {child_end}", nameof(children_count));
@@ -850,7 +850,7 @@ static void layout_items(Item item, int child_begin, int child_end, int children
 				}
 
 				// Now that the item has a frame, we can layout its children.
-				layout_item(child, child.Frame[2], child.Frame[3]);
+				layout_item(child, child.Frame[2], child.Frame[3], inMeasureMode);
 			}
 
 			if (layout.wrap && !layout.reverse2)