Microsoft.WindowsAPICodePack.Dialogs.CommonOpenFileDialog.GetDerivedOptionFlags C# (CSharp) Method

        internal override ShellNativeMethods.FileOpenOptions GetDerivedOptionFlags(ShellNativeMethods.FileOpenOptions flags)
        {
            if (multiselect)
            {
                flags |= ShellNativeMethods.FileOpenOptions.AllowMultiSelect;
            }
            if (isFolderPicker)
            {
                flags |= ShellNativeMethods.FileOpenOptions.PickFolders;
            }

            if (!allowNonFileSystem)
            {
                flags |= ShellNativeMethods.FileOpenOptions.ForceFilesystem;
            }
            else if (allowNonFileSystem)
            {
                flags |= ShellNativeMethods.FileOpenOptions.AllNonStorageItems;
            }

            return flags;
        }