如何使用自动映射器或其他方式将IQueryable映射到GenericList

Question

我列出了与各种类的多个连接的LINQ查询的结果输出。这发生在数据访问层我需要将其转换为业务对象列表

namespace App.Business.Entities
{
  public class GetAllFunction_VM
   {
    public GetAllFunction_VM()
    { }
    [Required]
    public int Function_ID { get; set; }
    [StringLength(250)]
    [Required]
    public string FunctionName { get; set; }
    public int Hierarchy_Level { get; set; }
    [Required]
    public int ParentID { get; set; }
    [StringLength(250)]
    [Required]
    public string ParentFunctionName { get; set; }
    public int ControllerID { get; set; }
    [StringLength(250)]
    [Required]
    public string ControllerName { get; set; }
    public int FunctionInControllerID { get; set; }
    public int ActionID { get; set; }
    [StringLength(250)]
    [Required]
    public string ActionName { get; set; }
    public int FunctionInActionID { get; set; }
   }
 }

业务对象

public List<FunctionNavigation_VM> GetAllFunctions()
    {
        List<FunctionNavigation_VM> FunctionNavigationListObject = new List<FunctionNavigation_VM>();
        try
        {
            using (var _uow = new FunctionsNavigation_UnitOfWork())
            {
                var entities = (from functionNavigation in _uow.Sys_Nav_Functions_Repository.GetAll()
                                join functionHierarchy in _uow.Sys_Nav_FunctionHierarchy_Repository.GetAll() on functionNavigation.Function_ID equals functionHierarchy.Function_ID
                                join functionNavigation_b in _uow.Sys_Nav_Functions_Repository.GetAll() on functionHierarchy.Parent_Function_ID equals functionNavigation_b.Function_ID
                                        into tmp from functionNavigation_b in tmp.DefaultIfEmpty()
                                join functionInController in _uow.Sys_Nav_FunctionInController_Repository.GetAll() on functionNavigation.Function_ID equals functionInController.Function_ID
                                join functionController in _uow.Sys_Nav_FunctionController_Repository.GetAll() on functionInController.ControllerID equals functionController.ControllerID
                                join functionInAction in _uow.Sys_Nav_FunctionInAction_Repository.GetAll() on functionNavigation.Function_ID equals functionInAction.Function_ID
                                join functionAction in _uow.Sys_Nav_FunctionAction_Repository.GetAll() on functionInAction.ActionID equals functionAction.ActionID
                                select new
                                {
                                    functionNavigation.Function_ID,
                                    FunctionName = functionNavigation.Title,
                                    functionNavigation.Hierarchy_Level,
                                    ParentID = functionHierarchy.Parent_Function_ID,
                                    ParentFunctionName = functionNavigation_b.Title,
                                    functionController.ControllerID,
                                    functionController.ControllerName,
                                    functionInController.FunctionInControllerID,
                                    functionAction.ActionID,
                                    functionAction.ActionName,
                                    functionInAction.FunctionInActionID
                                }
                               );
                //Map Data Entity to Business Entity
                //need help here... Auto Mapper 
              return FunctionNavigationListObject ;
            }
        }
        catch(Exception e)
        {
            return null;
        }
    }

Answer 1

既然您已经为您想要的结果类型生成了字段，那么就使用它作为您的投影类型:

public List<FunctionNavigation_VM> GetAllFunctions()
{
    using (var _uow = new FunctionsNavigation_UnitOfWork())
    {
        var entities = (from functionNavigation in _uow.Sys_Nav_Functions_Repository.GetAll()
                        join functionHierarchy in _uow.Sys_Nav_FunctionHierarchy_Repository.GetAll() on functionNavigation.Function_ID equals functionHierarchy.Function_ID
                        join functionNavigation_b in _uow.Sys_Nav_Functions_Repository.GetAll() on functionHierarchy.Parent_Function_ID equals functionNavigation_b.Function_ID
                                into tmp from functionNavigation_b in tmp.DefaultIfEmpty()
                        join functionInController in _uow.Sys_Nav_FunctionInController_Repository.GetAll() on functionNavigation.Function_ID equals functionInController.Function_ID
                        join functionController in _uow.Sys_Nav_FunctionController_Repository.GetAll() on functionInController.ControllerID equals functionController.ControllerID
                        join functionInAction in _uow.Sys_Nav_FunctionInAction_Repository.GetAll() on functionNavigation.Function_ID equals functionInAction.Function_ID
                        join functionAction in _uow.Sys_Nav_FunctionAction_Repository.GetAll() on functionInAction.ActionID equals functionAction.ActionID
                        select new FunctionNavigation_VM
                        {
                            functionNavigation.Function_ID,
                            FunctionName = functionNavigation.Title,
                            functionNavigation.Hierarchy_Level,
                            ParentID = functionHierarchy.Parent_Function_ID,
                            ParentFunctionName = functionNavigation_b.Title,
                            functionController.ControllerID,
                            functionController.ControllerName,
                            functionInController.FunctionInControllerID,
                            functionAction.ActionID,
                            functionAction.ActionName,
                            functionInAction.FunctionInActionID
                        }
                       );
      return entities.ToList(); ;
    }
}

请注意，我更改了投影以创建FunctionNavigation_VM对象并删除了try/catch块，因为吞下异常很少是一个好主意。要么做点什么，要么让它冒泡，在不同的层处理。