话不多说直接上代码。

/// <summary>
/// 把DataTable中数据快速插入指定表中
/// </summary>
/// <param name="connectionString">目标连接字符</param>
/// <param name="tableName">目标表（数据库表名）</param>
/// <param name="dataSource">源数据</param>
private void SqlBulkCopyByDatatable(string connectionString, string tableName, DataTable dataSource)
{
    SqlTransaction tran = null;//声明一个事务对象
    using (SqlConnection conn = new SqlConnection(connectionString))
    {
        conn.Open();
        using (tran = conn.BeginTransaction())
        {
            using (SqlBulkCopy sqlbulkcopy = new SqlBulkCopy(conn, SqlBulkCopyOptions.Default, tran))
            {
                try
                {
                    sqlbulkcopy.DestinationTableName = tableName;
                    sqlbulkcopy.WriteToServer(dataSource);
                    tran.Commit();
                }
                catch
                {
                    tran.Rollback();
                }
             }
         }
     }
 }