How to: Bind the GridControl to XPO

• Aug 23, 2018
• 4 minutes to read

This example shows how to provide the GridControl with data using the eXpress Persistent Objects (XPO).

1. Create a new persistent class representing a data object ProductDataObject (see the PersistentObject.cs file).

2. Define a database to store data.

C#

private void InitDAL() {
    XpoDefault.DataLayer = XpoDefault.GetDataLayer(
        AccessConnectionProvider.GetConnectionString(@"c:\database\product.mdb"),
        AutoCreateOption.DatabaseAndSchema
    );
}

VB.NET

Private Sub InitDAL()
    XpoDefault.DataLayer = XpoDefault.GetDataLayer(AccessConnectionProvider.GetConnectionString("c:\database\product.mdb"), AutoCreateOption.DatabaseAndSchema)
End Sub

3. Bind the GridControl to a new XPCollection object.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-display-data-via-xpo-e3283.

MainWindow.xaml.vb

Imports System.Windows
Imports DevExpress.Xpo
Imports DevExpress.Xpo.DB

Namespace DXGrid_BindingToXPODataSource
    ''' <summary>
    ''' Interaction logic for MainWindow.xaml
    ''' </summary>
    Partial Public Class MainWindow
        Inherits Window

        Public Sub New()
            InitDAL()
            GenerateData()
            InitializeComponent()
            grid.ItemsSource = New XPCollection(Of ProductDataObject)()
        End Sub

'        
'         * Creates a new DAL with the specified settings and initializes the XpoDefault.DataLayer property.
'         * As a result, all the units of work (or sessions) will by default access the "Product" database
'         * using the specified path.
'         
        Private Sub InitDAL()
            XpoDefault.DataLayer = XpoDefault.GetDataLayer(AccessConnectionProvider.GetConnectionString("c:\database\product.mdb"), AutoCreateOption.DatabaseAndSchema)
        End Sub

        ' Generates sample data if the "Product" database is empty.
        Private Sub GenerateData()
            If Session.DefaultSession.FindObject(Of ProductDataObject)(Nothing) IsNot Nothing Then
                Return
            End If
            Using uow As New UnitOfWork()
                Dim pdo1 As New ProductDataObject(uow) With {.ProductName = "Product A", .UnitPrice = 99}
                Dim pdo2 As New ProductDataObject(uow) With {.ProductName = "Product B", .UnitPrice = 199}
                uow.CommitChanges()
            End Using
        End Sub
    End Class
End Namespace

MainWindow.xaml

<Window x:Class="DXGrid_BindingToXPODataSource.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid">
    <Grid>
        <dxg:GridControl Name="grid" AutoPopulateColumns="True">
            <dxg:GridControl.View>
                <dxg:TableView Name="tableView1" />
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</Window>

PersistentObject.vb

Imports System
Imports DevExpress.Xpo

Namespace DXGrid_BindingToXPODataSource

    Public Class ProductDataObject
        Inherits XPObject

        Public Sub New()
            MyBase.New()
            ' This constructor is used when an object is loaded from a persistent storage.
            ' Do not place any code here.
        End Sub

        Public Sub New(ByVal session As Session)
            MyBase.New(session)
            ' This constructor is used when an object is loaded from a persistent storage.
            ' Do not place any code here.
        End Sub

        Public Overrides Sub AfterConstruction()
            MyBase.AfterConstruction()
            ' Place here your initialization code.
        End Sub

        Private fProductName As String
        Public Property ProductName() As String
            Get
                Return fProductName
            End Get
            Set(ByVal value As String)
                SetPropertyValue(Of String)("ProductName", fProductName, value)
            End Set
        End Property

        Private fUnitPrice As Integer
        Public Property UnitPrice() As Integer
            Get
                Return fUnitPrice
            End Get
            Set(ByVal value As Integer)
                SetPropertyValue(Of Integer)("UnitPrice", fUnitPrice, value)
            End Set
        End Property
    End Class
End Namespace

PersistentObject.cs

using System;
using DevExpress.Xpo;

namespace DXGrid_BindingToXPODataSource {

    public class ProductDataObject : XPObject {
        public ProductDataObject()
            : base() {
            // This constructor is used when an object is loaded from a persistent storage.
            // Do not place any code here.
        }

        public ProductDataObject(Session session)
            : base(session) {
            // This constructor is used when an object is loaded from a persistent storage.
            // Do not place any code here.
        }

        public override void AfterConstruction() {
            base.AfterConstruction();
            // Place here your initialization code.
        }

        private string fProductName;
        public string ProductName {
            get { return fProductName; }
            set { SetPropertyValue<string>("ProductName", ref fProductName, value); }
        }

        private int fUnitPrice;
        public int UnitPrice {
            get { return fUnitPrice; }
            set { SetPropertyValue<int>("UnitPrice", ref fUnitPrice, value); }
        }
    }
}

MainWindow.xaml.cs

using System.Windows;
using DevExpress.Xpo;
using DevExpress.Xpo.DB;

namespace DXGrid_BindingToXPODataSource {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitDAL();
            GenerateData();
            InitializeComponent();
            grid.ItemsSource = new XPCollection<ProductDataObject>();
        }

        /*
         * Creates a new DAL with the specified settings and initializes the XpoDefault.DataLayer property.
         * As a result, all the units of work (or sessions) will by default access the "Product" database
         * using the specified path.
         */
        private void InitDAL() {
            XpoDefault.DataLayer = XpoDefault.GetDataLayer(
                AccessConnectionProvider.GetConnectionString(@"c:\database\product.mdb"),
                AutoCreateOption.DatabaseAndSchema
            );
        }

        // Generates sample data if the "Product" database is empty.
        private void GenerateData() {
            if (Session.DefaultSession.FindObject<ProductDataObject>(null) != null) return;
            using (UnitOfWork uow = new UnitOfWork()) {
                ProductDataObject pdo1 = new ProductDataObject(uow) { ProductName = "Product A", UnitPrice = 99 };
                ProductDataObject pdo2 = new ProductDataObject(uow) { ProductName = "Product B", UnitPrice = 199 };
                uow.CommitChanges();
            }
        }
    }
}