change comparison

Xamarin.Forms.Core/Visual.cs

@@ -29,13 +29,13 @@ public override object ConvertFromInvariantString(string value)
  {
  if (value != null)
  {
- switch (value.Trim().ToLowerInvariant())
- {
- case "matchparent": return VisualMarker.MatchParent;
-  case "material": return VisualMarker.Material;
- case "default":
-  default: return VisualMarker.Default;
- }
+ var sc = StringComparison.OrdinalIgnoreCase;
+ if (value.Equals(nameof(VisualMarker.MatchParent), sc))
+ return VisualMarker.MatchParent;
+ else if (value.Equals(nameof(VisualMarker.Material), sc))
+ return VisualMarker.Material;
+ else
+  return VisualMarker.Default;
  }
  throw new InvalidOperationException($"Cannot convert \"{value}\" into {typeof(IVisual)}");
  }