fixed stale datetime picker default value

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [61.5.2]
+- [DateAndTimePicker][DatePicker][HorizontalInlineDatePicker] Fixed issue where the default value of pickers with no set value was reused and never updated until restart. 
+
 ## [61.5.1]
 - [Touch][iOS] Fixed scroll gestures on tappable rows getting stuck after dismissing context menus or picker popovers, and prevented taps behind open overlays from activating touch commands.
 

src/library/DIPS.Mobile.UI/Components/Pickers/DateAndTimePicker/DateAndTimePicker.Properties.cs

@@ -8,16 +8,20 @@ public partial class DateAndTimePicker
     public static readonly BindableProperty SelectedDateTimeProperty = BindableProperty.Create(
         nameof(SelectedDateTime),
         typeof(DateTime),
-        typeof(DateAndTimePicker), 
-        DateTime.Now,
+        typeof(DateAndTimePicker),
+        default(DateTime),
         defaultBindingMode:BindingMode.TwoWay,
         propertyChanged: (bindable, _, date) =>
         {
             if(date is not DateTime time)
                 return;
-            
+
             ((DateAndTimePicker)bindable).OnSelectedDateTimeChanged(time);
-        });
+        },
+        // A plain DateTime.Now default value is read only once and then shared by every picker,
+        // so all pickers showed the same frozen time until app restart. The creator runs once per
+        // picker, so each picker gets the current time instead.
+        defaultValueCreator: bindable => DateTime.Now);
 
     /// <summary>
     /// The date people selected from the date picker.

src/library/DIPS.Mobile.UI/Components/Pickers/DatePicker/DatePicker.Properties.cs

@@ -60,8 +60,12 @@ public DateTime? MaximumDate
             typeof(DateTime),
             typeof(DatePicker),
             defaultBindingMode:BindingMode.TwoWay,
-            defaultValue:DateTime.Now,
-            propertyChanged: (bindable, _, _) => ((DatePicker)bindable).OnSelectedDateChanged());
+            defaultValue:default(DateTime),
+            propertyChanged: (bindable, _, _) => ((DatePicker)bindable).OnSelectedDateChanged(),
+            // A plain DateTime.Now default value is read only once and then shared by every picker,
+            // so all pickers showed the same frozen time until app restart. The creator runs once per
+            // picker, so each picker gets the current time instead.
+            defaultValueCreator: bindable => DateTime.Now);
 
         public static readonly BindableProperty SelectedDateCommandProperty = BindableProperty.Create(
             nameof(SelectedDateCommand),

src/library/DIPS.Mobile.UI/Components/Pickers/DatePicker/HorizontalInLine/HorizontalInlineDatePicker.Properties.cs

@@ -5,11 +5,18 @@ public partial class HorizontalInlineDatePicker
     public static readonly BindableProperty SelectedDateProperty = BindableProperty.Create(
         nameof(SelectedDate),
         typeof(DateTime),
-        typeof(HorizontalInlineDatePicker), defaultValue: DateTime.Now, BindingMode.TwoWay, propertyChanged: (b, _, _) =>
+        typeof(HorizontalInlineDatePicker),
+        defaultValue: default(DateTime),
+        defaultBindingMode: BindingMode.TwoWay,
+        propertyChanged: (b, _, _) =>
         {
             if (b is not HorizontalInlineDatePicker horizontalInlineDatePicker) return;
             horizontalInlineDatePicker.OnSelectedDateChanged();
-        }) ;
+        },
+        // A plain DateTime.Now default value is read only once and then shared by every picker,
+        // so all pickers showed the same frozen time until app restart. The creator runs once per
+        // picker, so each picker gets the current time instead.
+        defaultValueCreator: b => DateTime.Now);
 
     /// <summary>
     /// The date that people selected from the horizontal in line date picker.