Question

我的Linq查询是。

string spouseName="jenny";
var empData = from sData in EmpList
              from member in sData.familyNames
              where string.Compare(member, spouseName, true) == 0
              select new Employee
              {
                  CompanyDept = sData.company,
                  EmpName = sData.empName,
                  FamilyNames.Add(spouse)   //ERROR HERE Not able to access as list
              };

此处empList为List<Employee>

class Employee
{
   private string companyDept
   private string empName
   private List<string> _familyNames = new List<string>();

   public string CompanyDept
   {
      get { return companyDept}
      set { companyDept= value; }
   }

   public string EmpName
   {
      get { return empName}
      set { empName= value; }
   }

   public List<string> FamilyNames 
   {
      get { return _familyNames }
      set { _familyNames = value; }
   }
}

问题：

这里我试图获得Employee类型的linq输出...但列表familyNames只包含一个项目配偶名称，而不是所有家庭成员的列表。??

但我在familyList收到错误。无法将项目添加到familyNames列表中以无法分配。

需要帮助，为什么会出现错误或者我错在某处？

Answer 1

正确的翻译是：

select new Employee
{
    CompanyDept = sData.company,
    EmpName = sData.empName,
    FamilyNames = { spouse } // 'nested' collection-initializer
};

原因是您只需要Add上的FamilyMember来电，而不是新列表的完整属性重新分配，这就是FamilyNames = new List<string> { spouse }做。

松散地说，这转化为：

var temp = new Employee();
temp.CompanyDept = sData.company;
temp.EmpName = sData.empName;
temp.FamilyNames.Add(spouse);
return temp; // this is selected.

Answer 2

您需要自己初始化列表。变化：

FamilyNames.Add(spouse)

要：

FamilyNames = new List<string>(new []{ spouse })

Answer 3

应该是

select new Employee
{
    CompanyDept = sData.company,
    EmpName = sData.empName,
   // FamilyNames.Add(spouse)   //ERROR HERE Not able to access as list
     FamilyNames = new List<string> {spouse}
} ;

虽然我原本期望sData.spouse或member.spouse

LINQ选择新错误。无法访问列表

3 个答案: