我在主页中创建了StorageFolder文件夹：
folderPicker.SuggestedStartLocation = PickerLocationId.Downloads;
folderPicker.ViewMode = PickerViewMode.Thumbnail;
folderPicker.FileTypeFilter.Add("*");
StorageFolder folder = await folderPicker.PickSingleFolderAsync();
然后我构建后台任务和触发器。 我想把“StorageFolder文件夹”传递给后台任务......怎么办？