sync thumbs on left/right arrow keys

Author: liakamp

Microsoft.Toolkit.Uwp.UI.Controls/RangeSelector/RangeSelector.cs

@@ -195,10 +195,12 @@ private void MinThumb_KeyDown(object sender, KeyRoutedEventArgs e)
             {
                 case VirtualKey.Left:
                     RangeMin -= 1;
+                    SyncThumbs();
                     e.Handled = true;
                     break;
                 case VirtualKey.Right:
                     RangeMin += 1;
+                    SyncThumbs();
                     e.Handled = true;
                     break;
             }
@@ -210,10 +212,12 @@ private void MaxThumb_KeyDown(object sender, KeyRoutedEventArgs e)
             {
                 case VirtualKey.Left:
                     RangeMax -= 1;
+                    SyncThumbs();
                     e.Handled = true;
                     break;
                 case VirtualKey.Right:
                     RangeMax += 1;
+                    SyncThumbs();
                     e.Handled = true;
                     break;
             }