[NUI] Prevent NullReferenceException when creating TextLabel

Signed-off-by: Jiyun Yang <ji.yang@samsung.com>

diff --git a/src/Tizen.NUI/src/public/Theme/ThemeManager.cs b/src/Tizen.NUI/src/public/Theme/ThemeManager.cs
index 615edbe..f41263c 100755 (executable)
--- a/src/Tizen.NUI/src/public/Theme/ThemeManager.cs
+++ b/src/Tizen.NUI/src/public/Theme/ThemeManager.cs
@@ -255,12 +255,12 @@ namespace Tizen.NUI
         /// <summary>
         /// Load a initial component style.
         /// </summary>
-        internal static ViewStyle GetInitialStyleWithoutClone(string styleName) => themeForInitialize.GetStyle(styleName);
+        internal static ViewStyle GetInitialStyleWithoutClone(string styleName) => themeForInitialize?.GetStyle(styleName);
 
         /// <summary>
         /// Load a initial component style.
         /// </summary>
-        internal static ViewStyle GetInitialStyleWithoutClone(Type viewType) => themeForInitialize.GetStyle(viewType);
+        internal static ViewStyle GetInitialStyleWithoutClone(Type viewType) => themeForInitialize?.GetStyle(viewType);
 
         /// <summary>
         /// Get a platform installed theme.