[NUI] Check null before call dispose

Signed-off-by: seungho <sbsh.baek@samsung.com>

diff --git a/src/Tizen.NUI/src/public/Transition/TransitionBase.cs b/src/Tizen.NUI/src/public/Transition/TransitionBase.cs
index ca7a690..7cc9849 100644 (file)
--- a/src/Tizen.NUI/src/public/Transition/TransitionBase.cs
+++ b/src/Tizen.NUI/src/public/Transition/TransitionBase.cs
@@ -92,8 +92,8 @@ namespace Tizen.NUI
         [EditorBrowsable(EditorBrowsableState.Never)]
         protected override void Dispose(DisposeTypes type)
         {
-            alphaFunction.Dispose();
-            timePeriod.Dispose();
+            alphaFunction?.Dispose();
+            timePeriod?.Dispose();
             base.Dispose(type);
         }
     }