c# - Submit GridView rows back to database -

i have c# code:

using (contractorsentities context = new contractorsentities(properties.settings.default.connection))         {             warningbindingsource.datasource = context.warnings.tolist();             educationlevelbindingsource.datasource = context.educationlevels.tolist();             penaltybindingsource.datasource = context.penalties.tolist();         } 

everything working fine without problems if add new rows gridview or updated rows example, how can submit data - new rows - database?

i know should call context.savechanges(); not work.

use context.warnings.local.tobindinglist() binding