/// <summary> /// 按月份分类图片 /// </summary> private async Task GroupImageAsync() { // 先初始化所有图片成一个list var imageViewModels = new List <ImageViewModel>(); foreach (var imageFolderList in _imageFolderLists) { foreach (var imageModel in imageFolderList.ImageModels) { var imageViewModel = await ImageViewModel.GetInstanceAsync(imageModel); imageViewModels.Add(imageViewModel); } } ImageMonthGroups = imageViewModels .GroupBy(m => m.MonthYearDate, (key, list) => new ImageMonthGroup(key, list)) .OrderByDescending(m => m.Key.WholeDateTime.Year).ThenByDescending(m => m.Key.WholeDateTime.Month); }