Form1.vb

Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.Xpo
Imports Northwind
Imports DevExpress.Data.Filtering
Imports DevExpress.Xpo.DB

Namespace Q205267_4

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            XpoDefault.ConnectionString = AccessConnectionProvider.GetConnectionString("..\..\nwind.mdb")
            ' Uncomment this code to create new database
            'using (UnitOfWork uow = new UnitOfWork()) {
            '    uow.ClearDatabase();
            '    Employees employee = new Employees(uow);
            '    employee.FirstName = "Thomas";
            '    employee.Save();
            '    uow.CommitChanges();
            '    for (int i = 0; i < 10; i++) {
            '        for (int j = 0; j < 10000; j++) {
            '            Orders order = new Orders(uow);
            '            order.ShipCity = "City";
            '            order.EmployeeID = employee;
            '        }
            '        uow.CommitChanges();
            '        Console.WriteLine(string.Format("{0} objects already created", i * 10000));
            '    }
            '}
            InitializeComponent()
        End Sub

        Private Sub myGridView1_MasterRowGetChildList(ByVal sender As Object, ByVal e As MasterRowGetChildListEventArgs)
            Dim view As GridView = CType(sender, GridView)
            Dim employee As Employees = CType(view.GetRow(e.RowHandle), Employees)
            Dim source As XPServerCollectionSource = CreateChildServerModeSource(employee)
            e.ChildList = CType(source, IListSource).GetList()
        End Sub

        Private Function CreateChildServerModeSource(ByVal employee As Employees) As XPServerCollectionSource
            Dim employeeId As Integer = employee.EmployeeID
            Dim op As CriteriaOperator = New BinaryOperator("EmployeeID", employeeId)
            Return New XPServerCollectionSource(employee.Session, GetType(Orders), op)
        End Function

        Private Sub myGridView1_MasterRowEmpty(ByVal sender As Object, ByVal e As MasterRowEmptyEventArgs)
            Dim view As GridView = CType(sender, GridView)
            Dim employee As Employees = CType(view.GetRow(e.RowHandle), Employees)
            Dim source As XPServerCollectionSource = CreateChildServerModeSource(employee)
            e.IsEmpty = CType(source, IListSource).GetList().Count = 0
        End Sub

        Private Sub myGridView1_MasterRowGetRelationCount(ByVal sender As Object, ByVal e As MasterRowGetRelationCountEventArgs)
            e.RelationCount = 1
        End Sub

        Private Sub myGridView1_MasterRowGetRelationName(ByVal sender As Object, ByVal e As MasterRowGetRelationNameEventArgs)
            e.RelationName = "Employee_Orders"
        End Sub
    End Class
End Namespace