fixing Flyout....

{

    public class Enums

    {

        public enum FileExt

        public enum StorageItemType

        {

            [Description("txt")]

            Txt,

            [Description("xml")]

            Xml,

            Folder

        }

        public enum FileReadingStatus

            return string.Join(string.Empty, "color", type.ToString().ToLowerInvariant());

        }

        public static string ToFileExt(this FileExt fileExt)

        public static string ToFileExt(this StorageItemType fileExt)

        {

            return string.Join(string.Empty, ".", fileExt.GetDescription());

        }

        }

        public string createFilenameForLocalSaving(string filepath,

                                                   FileExt fileExt,

                                                   StorageItemType fileExt,

                                                   SpectrumType spectrumType)

        {

            FileInfo fi = new FileInfo(filepath);

            string ext = string.Join(".", temp.ToArray());

            /* create new filename */

            if (fileExt != FileExt.Txt)

                ext = ext.Replace(FileExt.Txt.GetDescription(), fileExt.GetDescription());

            if (fileExt != StorageItemType.Txt)

                ext = ext.Replace(StorageItemType.Txt.GetDescription(), fileExt.GetDescription());

            string filename = string.Join(string.Empty, filenameNoExt, "_", spectrumType, ".", ext);

            return filename;

    <x:String x:Key="Ref">Ref</x:String>

    <x:String x:Key="RefWhite">RefWhite</x:String>

    <x:String x:Key="Xml">Xml</x:String>

    <x:String x:Key="Folder">Folder</x:String>

    <!-- CHROMELESS BUTTON STYLE -->

    <Style x:Key="ChromelessButtonStyle" TargetType="Button">

        </Border>

    </ControlTemplate>

    <!-- FLYOUT FOR OPENING RECENT STORAGE ITEMS -->

    <Flyout x:Name="RecentFilesFlyout"

            x:Key="RecentFilesFlyout"

            Placement="BottomEdgeAlignedLeft">

                       Visibility="{Binding Path=AreAvailable, Converter={StaticResource BoolToVisibilityInverseConverter}, Mode=OneWay}"

                       Margin="8"

                       Grid.Row="0" />

            <ListView ItemsSource="{Binding Path=RecentFiles, Mode=OneWay}"

            <ListView x:Name="listViewRecentItems"

                      ItemsSource="{Binding Path=RecentFiles, Mode=OneWay}"

                      IsItemClickEnabled="True"

                      SelectionMode="Single"

                      Visibility="{Binding Path=AreAvailable, Converter={StaticResource BoolToVisibilityConverter}, Mode=OneWay}"

                                   TextTrimming="CharacterEllipsis"/>

                    </DataTemplate>

                </ListView.ItemTemplate>

                <!-- BEHAVIORS -->

                <Interactivity:Interaction.Behaviors>

                    <Core:EventTriggerBehavior EventName="ItemClick">

                        <Core:InvokeCommandAction Command="{Binding CommandOpenSelectedSpectrumFile}"/>

                    </Core:EventTriggerBehavior>

                </Interactivity:Interaction.Behaviors>

            </ListView>

        </Grid>

    </Flyout>

            }

        }

        protected async Task<StorageFile> selectFileAsync(List<FileExt> fileExts)

        protected async Task<StorageFile> selectFileAsync(List<StorageItemType> fileExts)

        {

            StorageFile file = null;