[NUI] Fix NullReferenceException

Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object.

Change-Id: I625aed96587f6d2f1ecc0ea114ebc80af2dc9365
Signed-off-by: huiyu,eun <huiyu.eun@samsung.com>

diff --git a/src/Tizen.NUI/src/internal/Registry.cs b/src/Tizen.NUI/src/internal/Registry.cs
index cc03ca5..01a9168 100755 (executable)
--- a/src/Tizen.NUI/src/internal/Registry.cs
+++ b/src/Tizen.NUI/src/internal/Registry.cs
@@ -103,7 +103,7 @@ namespace Tizen.NUI
 
             if (Instance._controlMap.TryGetValue(refObjectPtr, out weakReference))
             {
-                BaseHandle ret = weakReference.Target as BaseHandle;
+                BaseHandle ret = weakReference?.Target as BaseHandle;
                 return ret;
             }
             else