Dim counties As New List(Of County)
 Dim dtCounties As DataTable
 dtCounties = _combinedRefRepository.Get_Counties()
 If dtCounties.Rows.Count <> 0 Then
    For Each row As DataRow In dtCounties.Rows
      Dim county As New County
      county.CountyId = row.Item(0).ToString()
      county.CountyName = row.Item(1).ToString().ToUpper()
      counties.Add(county)
    Next
    dtCounties.Dispose()
 End If

 Dim counties As New List(Of County)
 Dim dtCounties As DataTable
 dtCounties = _combinedRefRepository.Get_Counties()
 If dtCounties.Rows.Count <> 0 Then
    For Each row As DataRow In dtCounties.Rows
      Dim county As New County
      county.CountyId = row.Item(0).ToString()
      county.CountyName = row.Item(1).ToString().ToUpper()
      counties.Add(county)
    Next
    dtCounties.Dispose()
 End If

我意识到这里已经关门有一段时间了;然而，我有一个解决这个特定问题的解决方案，但需要稍微扭转:列和数据表需要预先定义/已经实例化。然后我只需将类型插入到数据表中。

下面是我所做的一个例子:

public static class Test
{
    public static void Main()
    {
        var dataTable = new System.Data.DataTable(Guid.NewGuid().ToString());

        var columnCode = new DataColumn("Code");
        var columnLength = new DataColumn("Length");
        var columnProduct = new DataColumn("Product");

        dataTable.Columns.AddRange(new DataColumn[]
            {
                columnCode,
                columnLength,
                columnProduct
            });

        var item = new List<SomeClass>();

        item.Select(data => new
        {
            data.Id,
            data.Name,
            data.SomeValue
        }).AddToDataTable(dataTable);
    }
}

static class Extensions
{
    public static void AddToDataTable<T>(this IEnumerable<T> enumerable, System.Data.DataTable table)
    {
        if (enumerable.FirstOrDefault() == null)
        {
            table.Rows.Add(new[] {string.Empty});
            return;
        }

        var properties = enumerable.FirstOrDefault().GetType().GetProperties();

        foreach (var item in enumerable)
        {
            var row = table.NewRow();
            foreach (var property in properties)
            {
                row[property.Name] = item.GetType().InvokeMember(property.Name, BindingFlags.GetProperty, null, item, null);
            }
            table.Rows.Add(row);
        }
    }
}

这是一个简单的控制台应用程序，用于将列表转换为数据表。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.ComponentModel;

namespace ConvertListToDataTable
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            List<MyObject> list = new List<MyObject>();
            for (int i = 0; i < 5; i++)
            {
                list.Add(new MyObject { Sno = i, Name = i.ToString() + "-KarthiK", Dat = DateTime.Now.AddSeconds(i) });
            }

            DataTable dt = ConvertListToDataTable(list);
            foreach (DataRow row in dt.Rows)
            {
                Console.WriteLine();
                for (int x = 0; x < dt.Columns.Count; x++)
                {
                    Console.Write(row[x].ToString() + " ");
                }
            }
            Console.ReadLine();
        }

        public class MyObject
        {
            public int Sno { get; set; }
            public string Name { get; set; }
            public DateTime Dat { get; set; }
        }

        public static DataTable ConvertListToDataTable<T>(this List<T> iList)
        {
            DataTable dataTable = new DataTable();
            PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(T));
            for (int i = 0; i < props.Count; i++)
            {
                PropertyDescriptor propertyDescriptor = props[i];
                Type type = propertyDescriptor.PropertyType;

                if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
                    type = Nullable.GetUnderlyingType(type);

                dataTable.Columns.Add(propertyDescriptor.Name, type);
            }
            object[] values = new object[props.Count];
            foreach (T iListItem in iList)
            {
                for (int i = 0; i < values.Length; i++)
                {
                    values[i] = props[i].GetValue(iListItem);
                }
                dataTable.Rows.Add(values);
            }
            return dataTable;
        }
    }
}

MSDN上的这个链接值得一看:如何:实现CopyToDataTable<T>，其中泛型类型T不是一个数据流

这增加了一个扩展方法，让你这样做:

// Create a sequence. 
Item[] items = new Item[] 
{ new Book{Id = 1, Price = 13.50, Genre = "Comedy", Author = "Gustavo Achong"}, 
  new Book{Id = 2, Price = 8.50, Genre = "Drama", Author = "Jessie Zeng"},
  new Movie{Id = 1, Price = 22.99, Genre = "Comedy", Director = "Marissa Barnes"},
  new Movie{Id = 1, Price = 13.40, Genre = "Action", Director = "Emmanuel Fernandez"}};

// Query for items with price greater than 9.99.
var query = from i in items
             where i.Price > 9.99
             orderby i.Price
             select i;

// Load the query results into new DataTable.
DataTable table = query.CopyToDataTable();

试试这个

public static DataTable ListToDataTable<T>(IList<T> lst)
{

    currentDT = CreateTable<T>();

    Type entType = typeof(T);

    PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(entType);
    foreach (T item in lst)
    {
        DataRow row = currentDT.NewRow();
        foreach (PropertyDescriptor prop in properties)
        {

            if (prop.PropertyType == typeof(Nullable<decimal>) || prop.PropertyType == typeof(Nullable<int>) || prop.PropertyType == typeof(Nullable<Int64>))
            {
                if (prop.GetValue(item) == null)
                    row[prop.Name] = 0;
                else
                    row[prop.Name] = prop.GetValue(item);
            }
            else
                row[prop.Name] = prop.GetValue(item);                    

        }
        currentDT.Rows.Add(row);
    }

    return currentDT;
}

public static DataTable CreateTable<T>()
{
    Type entType = typeof(T);
    DataTable tbl = new DataTable(DTName);
    PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(entType);
    foreach (PropertyDescriptor prop in properties)
    {
        if (prop.PropertyType == typeof(Nullable<decimal>))
             tbl.Columns.Add(prop.Name, typeof(decimal));
        else if (prop.PropertyType == typeof(Nullable<int>))
            tbl.Columns.Add(prop.Name, typeof(int));
        else if (prop.PropertyType == typeof(Nullable<Int64>))
            tbl.Columns.Add(prop.Name, typeof(Int64));
        else
             tbl.Columns.Add(prop.Name, prop.PropertyType);
    }
    return tbl;
}