EF中使用SqlBulkCopy

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using YX.Entity;

namespace YX.DAL.Extenstions
{
    public static class SqlBulkCopyHelper
    {
        public static void BulkInsertAll<T>(IEnumerable<T> entities)
        {
            entities = entities.ToArray();
            var cons = new Sam_DBEntities();
            string cs = cons.Database.Connection.ConnectionString;
            var conn = new SqlConnection(cs);
            conn.Open();

            Type t = typeof(T);

            var bulkCopy = new SqlBulkCopy(conn)
            {
                DestinationTableName = t.Name
            };

            var properties = t.GetProperties().Where(EventTypeFilter).ToArray();
            var table = new DataTable();

            foreach (var property in properties)
            {

                Type propertyType = property.PropertyType;
                if (propertyType.IsGenericType &&
                    propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
                {
                    propertyType = Nullable.GetUnderlyingType(propertyType);
                }

                table.Columns.Add(new DataColumn(property.Name, propertyType));
            }

            foreach (var entity in entities)
            {

                table.Rows.Add(properties.Select(
                  property => GetPropertyValue(
                  property.GetValue(entity, null), property.PropertyType.Name)).ToArray());
            }
            foreach (DataColumn dc in table.Columns)
            {
                bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping(dc.ColumnName, dc.ColumnName));
            }
            bulkCopy.WriteToServer(table);


          
            conn.Close();
        }

        private static bool EventTypeFilter(System.Reflection.PropertyInfo p)
        {
            var attribute = Attribute.GetCustomAttribute(p,
                typeof(AssociationAttribute)) as AssociationAttribute;

            if (attribute == null) return true;
            if (attribute.IsForeignKey == false) return true;

            return false;
        }

        private static object GetPropertyValue(object o, string type)
        {
            if (o == null)
            {
                return DBNull.Value;
            }
            
            return o;
        }
    }
}

 SqlBulkCopy sbc = new SqlBulkCopy(conPrivate);

 foreach (DataColumn dc in dt.Columns)
    sbc.ColumnMappings.Add(new SqlBulkCopyColumnMapping(dc.ColumnName, dc.ColumnName));