DataView.Count different DataView.Table.Rows.Count

Question

I am using C# and .NET 3.5 and have a GridView that I am setting the dataSource programatically in the code-behind page. I have data in a DataTable and then depending on a column value (isValid boolean) of each Row, I create a new row using DataRowView.AddNew() method into 1 of 2 DataViews - dvValid or dvInvalid. I am NOT creating a new DataTable.NewRow to add to the DataView Table. Then I bind the GridView to the appropriate dataView.

There is a problem when I am sorting the GridView. I am having a problem with 1 row not being sorted correctly, all other rows are sorted fine. I debugged my code and found that the DataView.Count is 1 more than the DataView.Table.Rows.Count even though I am calling DataView.Table.AcceptChanges() method. This is strange since the dataTable should have all committed rows and therefore the counts should be the same.

So why are the 2 counts different? A DataView is a subset of the DataTable so should it not have equal or less rows than the DataTable. When I populate the DataView, should I first create the DataTables rather than creating the DataView directly? Right now, I am directly creating a DataRowView without a dDataTableRow, is this the correct approach?

Thanks for your help.

Code snippet : C#

...

//get the data as DataTable
members = GetMemberDataTable ();

//create views from a new DataTable with no rows
dvValidMembers = new DataView (CreateMembersDT("ValidMembers"));
dvInValidMembers = new DataView (CreateMembersDT("InvalidMembers"));

//iterate thru each row and put into appropriate DataView
foreach (DataRow memberRow in members.Rows)
            {
                if ((bool)memberRow["isValid"])
                    //Add to valid members Dview
                    member = dvValidMembers.AddNew();
                else
                    //add to InValid members Dview
                    member = dvInvalidMembers.AddNew();

                member["memberID"] = memberRow["memID"];

            } //foreach

    dvInvalidMembers.Table.AcceptChanges();
    dvValidMembers.Table.AcceptChanges();

 }

 private System.Data.DataTable CreateMembersDT ( string tableName)
    {
        System.Data.DataTable dtMembers = new System.Data.DataTable(tableName);

        dtMembers.Columns.Add(new DataColumn("memID", typeof(int)));

        return dtMembers;
    }

Answer 1

That 1 row that isn't sorting right, could that be the last row?

I think you are missing a DataView.EndEdit():

foreach (DataRow memberRow in members.Rows)
{
    DataView dv;
    if (...) 
        //Add to valid members Dview
        dv = dvValidMembers;
    else
        dv = dvInvalidMembers;

    member = dv.Addnew();
    member["memberID"] = memberRow["memID"];
    dv.EndEdit();
}

But I would also like to note that you could probably use 2 Views with a Filter on isValid and then you would only need to point them to the original members table.