如何使用 lambda 表达式将 DataTable 记录添加到列表中？ [复制]

Question

在给定的代码中，我编写了 lambda 表达式，但它显示了一个错误——无法将 lambda 表达式转换为类型“字符串”，因为它不是委托类型。

        EmployeeDataOperation emp = new EmployeeDataOperation(); //Class to perform CRUD operation.

        List<EmployeeProp> data = new List<EmployeeProp>();

        dt = emp.getEmployeeData();//return datatable with records.

        //I want to use lambda expression to use Datatable data as a list
        data = (from a in dt
                select new EmployeeProp { Name = a.Name, Email = a.Email }).ToList();
        //error near select

        return View(data);

Answer 1

您可以使用.Field linq 扩展或索引/列名（ex row["columnname"] 访问来自DataRow 的值。我建议使用Field 扩展，因为它甚至可以处理nullable 类型。

data  = dt.AsEnumerable()
  .Select(row=>  new EmployeeProp ()
   {
       Name = row.Field<string>("Name"),
       Email = row.Field<string>("Email ") 
       // Other properties....      
   })
   .ToList();

Answer 2

你也可以试试这个，创建 EmployeeProp() 对象

data = (from a in dt
                select new EmployeeProp() { Name = a.Name, Email = a.Email }).ToList();

Answer 3

 var myData = (from a in dt.AsEnumerable()
               select new EmployeeProp { 
                   Name = a.Field<string>("Name"), 
                   Email = a.Field<string>("Email") 
              }).ToList();