fixed #276

src/Shared/HandyControl_Shared/Controls/Input/NumericUpDown.cs

@@ -25,6 +25,8 @@ namespace HandyControl.Controls
 
         private TextBox _textBox;
 
+        private bool _updateText;
+
         #endregion Data
 
         public NumericUpDown()
@@ -34,23 +36,18 @@ namespace HandyControl.Controls
                 if (IsReadOnly) return;
 
                 Value += Increment;
-                _textBox.Text = CurrentText;
-                _textBox.Select(_textBox.Text.Length, 0);
             }));
             CommandBindings.Add(new CommandBinding(ControlCommands.Next, (s, e) =>
             {
                 if (IsReadOnly) return;
 
                 Value -= Increment;
-                _textBox.Text = CurrentText;
-                _textBox.Select(_textBox.Text.Length, 0);
             }));
             CommandBindings.Add(new CommandBinding(ControlCommands.Clear, (s, e) =>
             {
                 if (IsReadOnly) return;
 
                 SetCurrentValue(ValueProperty, ValueBoxes.Double0Box);
-                _textBox.Text = string.Empty;
             }));
 
             Loaded += (s, e) => OnApplyTemplate();
@@ -98,7 +95,9 @@ namespace HandyControl.Controls
             if (!VerifyData()) return;
             if (double.TryParse(_textBox.Text, out var value))
             {
+                _updateText = false;
                 Value = value;
+                _updateText = true;
             }
         }
 
@@ -117,12 +116,10 @@ namespace HandyControl.Controls
             if (e.Key == Key.Up)
             {
                 Value += Increment;
-                _textBox.Text = CurrentText;
             }
             else if (e.Key == Key.Down)
             {
                 Value -= Increment;
-                _textBox.Text = CurrentText;
             }
         }
 
@@ -133,8 +130,6 @@ namespace HandyControl.Controls
             if (_textBox.IsFocused && !IsReadOnly)
             {
                 Value += e.Delta > 0 ? Increment : -Increment;
-                _textBox.Text = CurrentText;
-                _textBox.Select(_textBox.Text.Length, 0);
                 e.Handled = true;
             }
         }
@@ -173,9 +168,10 @@ namespace HandyControl.Controls
         {
             var ctl = (NumericUpDown) d;
             var v = (double) e.NewValue;
-            if (ctl._textBox != null)
+            if (ctl._updateText && ctl._textBox != null)
             {
-                ctl._textBox.Text = v.ToString();
+                ctl._textBox.Text = ctl.CurrentText;
+                ctl._textBox.Select(ctl._textBox.Text.Length, 0);
             }
 
             ctl.OnValueChanged(new FunctionEventArgs<double>(ValueChangedEvent, ctl)