C# 将C.net中的List转换为List

我有一个像UserEntity这样的类，如下所示

[Serializable]
[XmlRootAttribute(ElementName = "UsersEntity", IsNullable = false)]
public class UserEntity
{
    [XmlElement(DataType="string",ElementName="UsersID")]
    public int UsersID { get; set; }
    [XmlElement(DataType = "string", ElementName = "UserName")]
    public string UserName { get; set; }
    [XmlElement(DataType = "string", ElementName = "Password")]
    public string Password { get; set; }
}

然后，我从Db表中填充了一条记录作为数据集。然后，在没有foreach循环的情况下，我将该数据集转换为如下列表

Dataset _ods= new Dataset();  

//create a list of UerEntity class
List<UserEntity> lstUsers=new List<UserEntity>();

// populate record as dataset from DB table
_ods = populateEmpData();

// convert List<DataRow> from Dataset withou Foreach Loop
List<DataRow> lstRows = _ods.Tables[0].AsEnumerable().ToList();

---

但它不起作用。如何执行此操作？

您需要手动将DataRow字段映射到UserEntity类的字段。这样的东西应该可以在未经测试的情况下工作：

lstUsers = (from dr in lstRows
            select new UserEntity 
            {
                UsersId = dr.Field<int>("user_id"),
                UserName = dr.Field<string>("user_name"),
                Password = dr.Field<string>("password")
            }).ToList();

事实上，您不需要lstRows，也不需要将lstUsers初始化为空列表：

var lstUsers = (from dr in _ods.Tables[0].AsEnumerable()
                select new UserEntity 
                {
                    UsersId = dr.Field<int>("user_id"),
                    UserName = dr.Field<string>("user_name"),
                    Password = dr.Field<string>("password")
                }).ToList();

---

如何将单个数据行转换为用户类型？您是否可以只写DataRow x=ent；？

var lstUsers = (from dr in _ods.Tables[0].AsEnumerable()
                select new UserEntity 
                {
                    UsersId = dr.Field<int>("user_id"),
                    UserName = dr.Field<string>("user_name"),
                    Password = dr.Field<string>("password")
                }).ToList();