EF的连接对象 conventer DbConnection to SqlConnection

/// <summary>
/// 为 System.Data.SqlClient 提供的用于批量操作的方法。
///  一、SqlServer数据批量插入
///  SqlServer的批量插入很简单，使用SqlBulkCopy就可以，以下是该类的实现：
/// </summary>
public   class MsSqlBatcher : IBatcherProvider
{

/// <summary>
/// 将 <see cref="DataTable"/> 的数据批量插入到数据库中。
/// </summary>
/// <param name="dataTable">要批量插入的 <see cref="DataTable"/>。</param>
/// <param name="batchSize">每批次写入的数据量。</param>
public void Insert(string Import_ImportToTableName, DataTable dataTable, List<DbCorresExcelColumn> DBCorresExcelColumn, DbConnection dbconn, DbTransaction sqlbulkTransaction)
{
if (dataTable == null)
{
throw new ArgumentException("参数datatable 为空了");

}
if (dataTable.Rows.Count == 0)
{
return;
}
//先看看本身是不是Sql连接
SqlConnection sqlcon = dbconn as SqlConnection;

if (sqlcon == null)
{
//再看看是不是EF的连接.
var efcon = dbconn as System.Data.EntityClient.EntityConnection;
if (efcon != null)
{
sqlcon = efcon.StoreConnection as SqlConnection;
}
}

if (sqlcon == null)
{
throw new Exception("亲你连接的数据库不是mssqlserver.");
}

//sqlserver
using (SqlBulkCopy bulkCopy = new SqlBulkCopy(con, SqlBulkCopyOptions.Default, sqlbulkTransaction as SqlTransaction))
{
bulkCopy.DestinationTableName = Import_ImportToTableName;

foreach (var dbcxls in DBCorresExcelColumn)
{
//bulkCopy.ColumnMappings.Add 前面的参数是本地的临时Table列名，后面的参数是数据库的列名
bulkCopy.ColumnMappings.Add(dbcxls.ExcelColumnName, dbcxls.DbTableName);
}

try
{
bulkCopy.BatchSize = 20000;
bulkCopy.WriteToServer(dataTable);
}
catch (Exception ex)
{
throw ex;
}
finally
{
bulkCopy.Close();
}
}

}

mkswEntities DB = new mkswEntities();

using (DbConnection conn = DB.Connection)
{
...
Insert(..., conn, ...);
...
}