Try this:
Code:
private void BulkUpload(DataTable dt)
{
    dt.TableName="YourDataTable";
    string constr="your connection string";
    using(SqlConnection connection=new SqlConnection(constr))
    {
      connection.Open();
      //CreatingTranscationsothatitcanrollbackifgotanyerrorwhileuploading
      SqlTransaction trans=connection.BeginTransaction();
     //Start
...