在 C# 业务对象中转置数据

Question

我有以下场景，

List<Class> Classes = new List<Class>();
Class c1 = new Class() { ClassID = 1, Name = "Class1", Abbreviation = "CLS1" }; Classes.Add(c1);
Class c2 = new Class() { ClassID = 2, Name = "Class2", Abbreviation = "CLS2" }; Classes.Add(c2);
Class c3 = new Class() { ClassID = 3, Name = "Class3", Abbreviation = "CLS3" }; Classes.Add(c3);

List<ClassCode> ClassCodes = new List<ClassCode>();
ClassCode cc1 = new ClassCode() { ClassID = 1, ClassCodeID = 1, Code = "CC1", Description = "CCD1", Class = c1 }; ClassCodes.Add(cc1);
ClassCode cc2 = new ClassCode() { ClassID = 1, ClassCodeID = 2, Code = "CC2", Description = "CCD2", Class = c1 }; ClassCodes.Add(cc2);
ClassCode cc3 = new ClassCode() { ClassID = 2, ClassCodeID = 3, Code = "CC3", Description = "CCD3", Class = c2 }; ClassCodes.Add(cc3);
ClassCode cc4 = new ClassCode() { ClassID = 2, ClassCodeID = 4, Code = "CC4", Description = "CCD4", Class = c2 }; ClassCodes.Add(cc4);
ClassCode cc5 = new ClassCode() { ClassID = 3, ClassCodeID = 5, Code = "CC5", Description = "CCD5", Class = c3 }; ClassCodes.Add(cc5);
ClassCode cc6 = new ClassCode() { ClassID = 3, ClassCodeID = 6, Code = "CC6", Description = "CCD6", Class = c3 }; ClassCodes.Add(cc6);

我尝试使用 Linq 将上述数据转置为以下格式

Class1   | CLS1    |    Class2   | CLS2   | Class3   | CLS3     - Columns
---------------------------------------------------------------------------
CCD1CCD2 |  CC1CC2 |   CCD3CCD4  | CC3CC4 | CCD5CCD6 | CC4CC5    - Row

• 列标题是基于 ClassID (ClassCode) 分组的名称（类）和缩写（类）的值
• 值是代码的串联(ClassCode) 和描述 (ClassCode) - 映射是代码转到缩写列，描述转到名称列

• 当您想要在运行时创建属性时，数据表适合 - 任何其他选项都可以赞赏。

  请帮忙！！

Answer 1

您没有解释为什么要这样做。
可能还有其他方法可以实现您想要的目标。

无论如何，下面的代码应该可以工作。
它生成一个 DataTable，我认为它非常适合此目的：

var dt = new System.Data.DataTable("Transpose");           

foreach (var c in Classes)
{
    var dc1 = new System.Data.DataColumn(c.Name, typeof(string));
    var dc2 = new System.Data.DataColumn(c.Abbreviation, typeof(string));
    dc1.ExtendedProperties.Add("ID", c.ClassID);
    dc2.ExtendedProperties.Add("ID", c.ClassID);
    dt.Columns.AddRange(new System.Data.DataColumn[] { dc1, dc2 } );
}

var dr = dt.NewRow();

for (int i = 0; i < dt.Columns.Count; i++)
{
    var col = dt.Columns[i];
    dr[i++] = ClassCodes.Where(cc => cc.ClassID == (int)col.ExtendedProperties["ID"])
                        .Select(cc => cc.Description)
                        .Aggregate((first, next) => first + next);
    col = dt.Columns[i];
    dr[i] = ClassCodes.Where(cc => cc.ClassID == (int)col.ExtendedProperties["ID"])
                      .Select(cc => cc.Code)
                      .Aggregate((first, next) => first + next);
 }

 dt.Rows.Add(dr);