From a4a96cbf4f2d3600accf7a34ed6fec898d5a261b Mon Sep 17 00:00:00 2001
From: Patrick Kranz <p.kranz@seeburger.de>
Date: Wed, 23 May 2018 13:23:19 +0200
Subject: [PATCH] Fix exception in sample Project.

---
 NSCI/UI/Controls/TextBlock.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/NSCI/UI/Controls/TextBlock.cs b/NSCI/UI/Controls/TextBlock.cs
index d170949..83a83df 100644
--- a/NSCI/UI/Controls/TextBlock.cs
+++ b/NSCI/UI/Controls/TextBlock.cs
@@ -12,7 +12,8 @@ public partial class TextBlock : FrameworkElement
         [NDProperty.NDP]
         protected virtual void OnTextChanging(NDProperty.Propertys.OnChangingArg<NDPConfiguration, string> arg)
         {
-            arg.Provider.MutatedValue = arg.Provider.NewValue?.Replace("\t", "    ").Replace("\r", "");
+            if (arg.Provider.CanMutate)
+                arg.Provider.MutatedValue = arg.Provider.NewValue?.Replace("\t", "    ").Replace("\r", "");
             if (arg.Property.IsObjectValueChanging)
                 arg.ExecuteAfterChange += (sender, e) =>
                 {