public static void LoadPackages()
        {
            if (Application.isPlaying || _loaded)
            {
                return;
            }

            EditorApplication.update -= EditorApplication_Update;
            EditorApplication.update += EditorApplication_Update;

            _loaded = true;

            UIPackage.RemoveAllPackages();
            FontManager.Clear();
            NTexture.DisposeEmpty();
            UIObjectFactory.Clear();

            string[] ids = AssetDatabase.FindAssets("_fui t:textAsset");
            int      cnt = ids.Length;

            for (int i = 0; i < cnt; i++)
            {
                string assetPath = AssetDatabase.GUIDToAssetPath(ids[i]);
                int    pos       = assetPath.LastIndexOf("_fui");
                if (pos == -1)
                {
                    continue;
                }

                assetPath = assetPath.Substring(0, pos);
                if (AssetDatabase.AssetPathToGUID(assetPath) != null)
                {
                    UIPackage.AddPackage(assetPath,
                                         (string name, string extension, System.Type type, out DestroyMethod destroyMethod) =>
                    {
                        destroyMethod = DestroyMethod.Unload;
                        return(AssetDatabase.LoadAssetAtPath(name + extension, type));
                    }
                                         );
                }
            }

            List <UIPackage> pkgs = UIPackage.GetPackages();

            pkgs.Sort(CompareUIPackage);

            cnt = pkgs.Count;
            packagesPopupContents = new GUIContent[cnt + 1];
            for (int i = 0; i < cnt; i++)
            {
                packagesPopupContents[i] = new GUIContent(pkgs[i].name);
            }
            packagesPopupContents[cnt] = new GUIContent("Please Select");

            EMRenderSupport.Reload();
        }