Use CultureInfo.CurrentCulture for string conversions of Value (#3860)

Author: nicolaihenriksen

src/MaterialDesignThemes.Wpf/UpDownBase.cs

@@ -118,7 +118,7 @@ private static void OnNumericValueChanged(DependencyObject d, DependencyProperty
 
         if (upDownBase._textBoxField is { } textBox)
         {
-            textBox.Text = e.NewValue.ToString();
+            textBox.Text = Convert.ToString(e.NewValue, CultureInfo.CurrentCulture);
         }
 
         upDownBase.UpdateDecreaseButtonEnabled();
@@ -224,7 +224,7 @@ public override void OnApplyTemplate()
         {
             _textBoxField.TextChanged += OnTextBoxTextChanged;
             _textBoxField.LostFocus += OnTextBoxLostFocus;
-            _textBoxField.Text = Value?.ToString();
+            _textBoxField.Text = Convert.ToString(Value, CultureInfo.CurrentCulture);
         }
 
     }
@@ -233,15 +233,15 @@ private void OnTextBoxLostFocus(object sender, EventArgs e)
     {
         if (_textBoxField is { } textBoxField)
         {
-            textBoxField.Text = Value?.ToString();
+            textBoxField.Text = Convert.ToString(Value, CultureInfo.CurrentCulture);
         }
     }
 
     private void OnTextBoxTextChanged(object sender, EventArgs e)
     {
         if (_textBoxField is { } textBoxField)
         {
-            if (TryParse(textBoxField.Text, CultureInfo.CurrentUICulture, out T? value))
+            if (TryParse(textBoxField.Text, CultureInfo.CurrentCulture, out T? value))
             {
                 SetCurrentValue(ValueProperty, ClampValue(value));
             }