Inside Button Click Even
t, you are getting the
CheckBoxList assignee = (CheckBoxList)grvStudentDetails.Rows[rowIndex].Cells.FindControl("chkAssignees");
Now get all the checked ones and store their item index separated by comma or something in one column like...
foreach (ListItem item in assignee.Items)
Then while restoring the data, retrieve from that column and split the string to get the index or values and check the
matching with those.
Please get started on this. You will explore many things. :)