Exclude Combo box items that held in a datagridview

Question

I have a combo box that is attached to a datasource

cboPies.DataSource = GetPies(txtCustomer.Text)
cboPies.DisplayMember = "PIES_DESCN"
cboPies.ValueMember = "PIES_ID"

I also have a datagridView that has a list of selections that have selected from the combo box .

I am trying to remove the items for the combo box if they have already have the item on the Datagridview or warn the user that it is already selected.

With dgvSelectedPies
    For indexDGV As Integer = 0 To .Rows.Count - 1 Step 1
        'cboSpecialty.Items.Remove(.Rows(indexDGV).Cells("PIES_DESCN").Value)
        cboSpecialty.Items.Remove(.Rows(indexDGV).Cells("PIES_ID").Value)

    Next
End With

Answer 1

If you are using a data source then you should not be interacting with the Items collection. The MSDN documentation says :

A data source can be a database, a Web service, or an object that can later be used to generate data-bound controls. When the DataSource property is set, the items collection cannot be modified .

Instead, you should be managing your own collection using a BindingList .

Example in C# (sorry):

protected BindingList<Pies> ComboDataSource { get; set; }

...

ComboDataSource = new BindingList<Pies>(GetPies(txtCustomer.Text));
cboPies.DataSource = ComboDataSource;
cboPies.DisplayMember = "PIES_DESCN"
cboPies.ValueMember = "PIES_ID"

...

if(ComboDataSource.Contains(pieInDataGrid))
{
    ComboDataSource.Remove(pieInDataGrid);
}