From 0669e78ec71b4d3ed664ff2591eb9cf12aa2f21a Mon Sep 17 00:00:00 2001
From: brianlagunas_cp <XceedBoucherS@users.noreply.github.com>
Date: Tue, 29 Mar 2011 14:57:12 +0000
Subject: [PATCH] NumericUpDown and DateTimeUpDown: added NullValue property
 which allows you to set a default value if the bound value is null.  The
 NullValue will be used when the increment/decrement buttons are pressed on a
 null value.

---
 .../Implementation/DateTimeUpDown.cs          | 20 +++++++++++++++++--
 .../Implementation/NumericUpDown.cs           | 16 +++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/Implementation/DateTimeUpDown.cs b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/Implementation/DateTimeUpDown.cs
index 05f0bcdd..f2857cf6 100644
--- a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/Implementation/DateTimeUpDown.cs
+++ b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/Implementation/DateTimeUpDown.cs
@@ -75,6 +75,18 @@ namespace Microsoft.Windows.Controls
 
         #endregion //FormatString
 
+        #region NullValue
+
+        public static readonly DependencyProperty NullValueProperty = DependencyProperty.Register("NullValue", typeof(DateTime), typeof(DateTimeUpDown), new UIPropertyMetadata(DateTime.Now));
+        public DateTime NullValue
+        {
+            get { return (DateTime)GetValue(NullValueProperty); }
+            set { SetValue(NullValueProperty, value); }
+        }
+        
+
+        #endregion //NullValue
+
         #region Value
 
         public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("Value", typeof(DateTime?), typeof(DateTimeUpDown), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnValueChanged, OnCoerceValue));
@@ -215,14 +227,18 @@ namespace Microsoft.Windows.Controls
 
         protected override void OnIncrement()
         {
-            if (Value != null)
+            if (Value.HasValue)
                 UpdateDateTime(1);
+            else
+                Value = NullValue;
         }
 
         protected override void OnDecrement()
         {
-            if (Value != null)
+            if (Value.HasValue)
                 UpdateDateTime(-1);
+            else
+                Value = NullValue;
         }
 
         #endregion //Abstract
diff --git a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/NumericUpDown/Implementation/NumericUpDown.cs b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/NumericUpDown/Implementation/NumericUpDown.cs
index 117a7a31..2e054b71 100644
--- a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/NumericUpDown/Implementation/NumericUpDown.cs
+++ b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/NumericUpDown/Implementation/NumericUpDown.cs
@@ -86,6 +86,18 @@ namespace Microsoft.Windows.Controls
 
         #endregion //FormatString
 
+        #region NullValue
+
+        public static readonly DependencyProperty NullValueProperty = DependencyProperty.Register("NullValue", typeof(decimal), typeof(NumericUpDown), new UIPropertyMetadata(default(decimal)));
+        public decimal NullValue
+        {
+            get { return (decimal)GetValue(NullValueProperty); }
+            set { SetValue(NullValueProperty, value); }
+        }
+        
+
+        #endregion //NullValue
+
         #region SelectAllOnGotFocus
 
         public static readonly DependencyProperty SelectAllOnGotFocusProperty = DependencyProperty.Register("SelectAllOnGotFocus", typeof(bool), typeof(NumericUpDown), new PropertyMetadata(false));
@@ -199,12 +211,16 @@ namespace Microsoft.Windows.Controls
         {
             if (Value.HasValue)
                 Value += Increment;
+            else
+                Value = NullValue;
         }
 
         protected override void OnDecrement()
         {
             if (Value.HasValue)
                 Value -= Increment;
+            else
+                Value = NullValue;
         }
 
         protected override void OnPreviewKeyDown(KeyEventArgs e)