将DataTable中的2列与List中的2列进行比较，并使用特定条件构建新的列表

如何解决将DataTable中的2列与List中的2列进行比较，并使用特定条件构建新的列表

我有DataTable

public static DataTable SubProjects = new DataTable();

public static DataTable GetSubProjects
{
    get { return SubProjects; }
}

它来自数据库，因此列如下

select ProjectN,ProjectSubN,ProjectM

并列出：

public class SubProjectsList
{
    public string ProjectNumber { get; set; }
    public string SubProjectNumber { get; set; }
    public string SubProjectName { get; set; }
    public string ProjectManager { get; set; }
    public int ObjectID { get; set; }

    public SubProjectsList(string ProjectNumber,string SubProjectNumber,string SubProjectName,string ProjectManager,int ObjectID)
    {
        this.ProjectNumber = ProjectNumber;
        this.SubProjectNumber = SubProjectNumber;
        this.SubProjectName = SubProjectName;
        this.ProjectManager = ProjectManager;
        this.SubProjectNumber = SubProjectNumber;
        this.ObjectID = ObjectID;
    }
}

public static List<SubProjectsList> DeliverySubProjectList = new List<SubProjectsList>();

最终，我想将所有结果保存到新列表中，

ProjectN + ProjectSubN (DataTable) = ProjectNumber + SubProjectNumber (List) && 
ProjectM (DataTable) != ProjectManager (List)

作为输出，我需要获取ProjectNumber，SubProjectNumber，ProjectM，ProjectManager。基本上，我需要捕获与一个子项目不匹配的ProjectM和ProjectManager。我本可以这样做

var SubProjectResult = SubProjects.AsEnumerable()
    .Where(x => DeliverySubProjectList.Any(y => 
    y.ProjectNumber.Trim() + y.SubProjectNumber == x.Field<string>("ProjectN").Trim() + x.Field<string>("ProjectSubN").Trim() &&
    !string.Equals(y.ProjectManager.Trim(),x.Field<string>("ProjectM").Trim(),StringComparison.CurrentCultureIgnoreCase)))
    .Select(x => new
    {
        ProjectN = x.Field<string>("ProjectN"),ProjectN = x.Field<string>("ProjectSubN"),ProjectM = x.Field<string>("ProjectM"),ProjectM = x.ProjectManager // This is not possible
    })
    .OrderBy(o => o.ProjectN).ToList();

但是

ProjectM = x.ProjectManager // This is not possible

是错误的，无法编译。因此，我无法从ProjectManager匹配的列表中获得ProjectN + ProjectSubN (DataTable) = ProjectNumber + SubProjectNumber (List)，但ProjectManager不匹配。我需要先将Concat DataTable和List一起使用吗？我已经尝试过了

var myList1 = SubProjects.AsEnumerable().Concat(DeliverySubProjectList).ToList();

但出现错误

严重性代码描述项目文件行抑制状态 错误CS1929“ EnumerableRowCollection”不包含 “ Concat”的定义和最佳扩展方法重载 'Queryable.Concat（IQueryable， IEnumerable）'需要类型的接收器 “可查询”

解决方法

我认为这应该为您提供所需的东西。您可能需要添加额外的空检查，而我也不是很确定要从列表和数据表中添加字符串值的方式：

public class ResultModel
        {
            public string ProjectNumber { get; set; }
            public string SubProjectNumber { get; set; }
            public string ProjectM { get; set; }
            public string ProjectManager { get; set; }
        }

...
...
static void Main(string[] args)
        {
            List<SubProjectsList> DeliverySubProjectList = // populate list
            DataTable SubProjects = // populate datatable
            List<ResultModel> results = GetResults(DeliverySubProjectList,SubProjects).ToList();
        }

        private static IEnumerable<ResultModel> GetResults(List<SubProjectsList> DeliverySubProjectList,DataTable SubProjects)
        {
            return SubProjects.AsEnumerable().Select(row =>
            {
                var listItem = DeliverySubProjectList.FirstOrDefault(item =>
                {
                    return item.ProjectNumber + item.SubProjectNumber == row["ProjectN"].ToString() + row["ProjectSubN "].ToString()
                        && !item.ProjectManager.Equals(row["ProjectM"].ToString());

                });

                if (listItem != null)
                {
                    return new ResultModel
                    {
                        ProjectNumber = row["ProjectN"].ToString(),SubProjectNumber = listItem.SubProjectNumber,ProjectM = row["ProjectM"].ToString(),ProjectManager = listItem.ProjectManager
                    };
                }
                else
                {
                    return null;
                }
            })
            .Where(res => res != null);
        }