c# - 如何根据 id 从列表中进行不同的选择？

Question

我有以下列表，但我想要基于 catID 的不同行，我怎样才能实现这一点？

lst.AddRange(
            (from xx in this.FreeInstructionItems
             select new selectedCustomization()
             {
                 TypeName = CategoryType.SpecialInstruction,
                 CategoryName = xx.InstructionInfo.CatName,
                 ItemName = xx.InstructionInfo.Description,
                 SourceID = xx.InstructionInfo.InstructionId,
                 CatID = xx.InstructionInfo.CatID,
                 Items = GetAllFreeItemNames(CategoryType.SpecialInstruction, xx.InstructionInfo.CatID)
             }
            ).ToList()
            );
return lst;

Answer 1

MoreLINQ而且 DistinctBy 比所有 GroupBy hack 都要好:

return lst.DistinctBy(x => x.CatID);