[Windows] Fix for TimePicker rendering a default time when its value is null

src/Controls/tests/TestCases.HostApp/Issues/Issue32266.cs

@@ -0,0 +1,52 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 32266, "TimePicker on Windows Defaults to Midnight When Time Value Is Null", PlatformAffected.UWP)]
+public class Issue32266 : ContentPage
+{
+	TimePicker timePicker;
+	Button clearTimeButton;
+	Button setTimeButton;
+
+	public Issue32266()
+	{
+		timePicker = new TimePicker
+		{
+			AutomationId = "Issue32266TimePicker",
+			Time = null,
+			Format = "hh:mm"
+		};
+
+		setTimeButton = new Button
+		{
+			AutomationId = "SetTimeButton",
+			Text = "Set Time to 6:00 AM"
+		};
+		setTimeButton.Clicked += SetTime_Clicked;
+
+		clearTimeButton = new Button
+		{
+			AutomationId = "ClearTimeButton",
+			Text = "Clear Time (Set to Null)"
+		};
+		clearTimeButton.Clicked += ClearTime_Clicked;
+
+		VerticalStackLayout stackLayout = new VerticalStackLayout
+		{
+			Padding = 25,
+			Spacing = 10,
+			Children = { timePicker, setTimeButton, clearTimeButton }
+		};
+
+		Content = stackLayout;
+	}
+
+	void SetTime_Clicked(object sender, EventArgs e)
+	{
+		timePicker.Time = new TimeSpan(6, 0, 0);
+	}
+
+	void ClearTime_Clicked(object sender, EventArgs e)
+	{
+		timePicker.Time = null;
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue32266.cs

@@ -0,0 +1,35 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue32266 : _IssuesUITest
+{
+	public Issue32266(TestDevice device) : base(device)
+	{
+	}
+
+	public override string Issue => "TimePicker on Windows Defaults to Midnight When Time Value Is Null";
+
+	[Test, Order(1)]
+	[Category(UITestCategories.TimePicker)]
+	public void VerifyTimePickerIsNullOnInitialLoad()
+	{
+		App.WaitForElement("Issue32266TimePicker");
+		VerifyScreenshot();
+	}
+
+	[Test, Order(2)]
+	[Category(UITestCategories.TimePicker)]
+	public void VerifyClearedTimeDoesNotShowMidnight()
+	{
+		App.WaitForElement("SetTimeButton");
+		App.Tap("SetTimeButton");
+
+		App.WaitForElement("ClearTimeButton");
+		App.Tap("ClearTimeButton");
+
+		VerifyScreenshot();
+	}
+}

src/Core/src/Handlers/TimePicker/TimePickerHandler.Windows.cs

@@ -9,12 +9,12 @@ public partial class TimePickerHandler : ViewHandler<ITimePicker, TimePicker>
 
 		protected override void ConnectHandler(TimePicker platformView)
 		{
-			platformView.TimeChanged += OnControlTimeChanged;
+			platformView.SelectedTimeChanged += OnSelectedTimeChanged;
 		}
 
 		protected override void DisconnectHandler(TimePicker platformView)
 		{
-			platformView.TimeChanged -= OnControlTimeChanged;
+			platformView.SelectedTimeChanged -= OnSelectedTimeChanged;
 		}
 
 		public static void MapFormat(ITimePickerHandler handler, ITimePicker timePicker)
@@ -54,7 +54,7 @@ internal static void MapIsOpen(ITimePickerHandler handler, ITimePicker timePicke
 			handler.PlatformView?.UpdateIsOpen(timePicker);
 		}
 
-		void OnControlTimeChanged(object? sender, TimePickerValueChangedEventArgs e)
+		void OnSelectedTimeChanged(TimePicker sender, TimePickerSelectedValueChangedEventArgs e)
 		{
 			if (VirtualView is not null)
 			{

src/Core/src/Platform/Windows/TimePickerExtensions.cs

@@ -13,7 +13,7 @@ public static class TimePickerExtensions
 {
 	public static void UpdateTime(this TimePicker nativeTimePicker, ITimePicker timePicker)
 	{
-		nativeTimePicker.Time = timePicker.Time ?? TimeSpan.Zero;
+		nativeTimePicker.SelectedTime = timePicker.Time;
 
 		if (timePicker.Format?.Contains('H', StringComparison.Ordinal) == true)
 		{