fix slider localization bug

src/Libraries/CoreNodeModelsWpf/SliderViewModel.cs

@@ -1,5 +1,5 @@
-using System;
-
+using System;
+using System.Globalization;
 using CoreNodeModels.Input;
 
 using Dynamo.Core;
@@ -63,7 +63,16 @@ public T Value
                 if (value.CompareTo(model.Min) == -1)
                     model.Min = value;
 
-                model.UpdateValue(new Dynamo.Graph.UpdateValueParams(nameof(Value), value.ToString()));
+                if(value is IFormattable formattableval)
+                {
+                    var invariantString  = formattableval.ToString(null,CultureInfo.InvariantCulture);
+                    model.UpdateValue(new Dynamo.Graph.UpdateValueParams(nameof(Value), invariantString));
+                }
+                else
+                {
+                    model.UpdateValue(new Dynamo.Graph.UpdateValueParams(nameof(Value), value.ToString()));
+                }
+
             }
         }
 
@@ -98,4 +107,4 @@ private void model_PropertyChanged(
         }
 
     }
-}
+}

test/DynamoCoreWpfTests/SliderViewModelTests.cs

@@ -1,6 +1,8 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Reflection;
+using System.Threading;
 using System.Windows.Controls;
 using CoreNodeModels;
 using CoreNodeModels.Input;
@@ -132,5 +134,44 @@ public void SliderViewModel_ValueTest()
             Assert.AreEqual("-200", minTextBox.Text);
             Assert.AreEqual("200", maxTextBox.Text);
         }
+
+        /// <summary>
+        /// This test will validate that setting the string in a , dec seperator culture does not
+        /// modify the value.
+        /// </summary>
+        [Test]
+        public void SliderViewModel_ValueTest_Localized()
+        {
+            //change current thread culture to German.
+            var deCulture = CultureInfo.CreateSpecificCulture("de-DE");
+
+            var currentCulture = Thread.CurrentThread.CurrentCulture;
+            var currentUICulture = Thread.CurrentThread.CurrentUICulture;
+
+            Thread.CurrentThread.CurrentCulture = deCulture;
+            Thread.CurrentThread.CurrentUICulture = deCulture;
+
+            //create a slider
+            var slider = new CoreNodeModels.Input.DoubleSlider();
+            Model.CurrentWorkspace.AddAndRegisterNode(slider);
+
+            DispatcherUtil.DoEvents();
+
+            //get viewmodel.
+            var nodeViews = View.NodeViewsInFirstWorkspace();
+            var nodeView = nodeViews.OfNodeModelType<CoreNodeModels.Input.DoubleSlider>().FirstOrDefault();
+            var dynamoSliderControl = nodeView.grid.ChildrenOfType<DynamoSlider>().FirstOrDefault();
+            //Setting the Value property from the SliderViewModel
+            var sliderViewModel = dynamoSliderControl.DataContext as SliderViewModel<double>;
+            sliderViewModel.Value = 10.7;
+
+            DispatcherUtil.DoEvents();
+
+            Assert.AreEqual(10.7,slider.Value);
+            //reset culture
+            Thread.CurrentThread.CurrentCulture = currentCulture;
+            Thread.CurrentThread.CurrentUICulture = currentUICulture;
+
+        }
     }
 }