Data Grid for WPF - How to Update Data in a Separate Thread

This example demostrates how to update GridControl data in a separate thread. To
synchronize access to data, call the BeginDataUpdate and EndDataUpdate methods. These methods allow you to lock updates within the GridControl, process data updates, and then apply all changes to the control.

Create a custom service that calls the GridControl methods. Use the Dispatcher to invoke these methods in the UI thread.

C#
...  
public interface IGridUpdateService {  
    void BeginUpdate();  
    void EndUpdate();  
}  

public class GridUpdateService : ServiceBase, IGridUpdateService {  
    //...  

    public void BeginUpdate() {  
        Dispatcher.Invoke(new Action(() => {  
            if (GridControl != null) {  
                GridControl.BeginDataUpdate();  
            }  
        }));  
    }  

    public void EndUpdate() {  
       //...  
    }  
}  
...

Add the service to your View and assosiate this service with the GridControl.

XAML
<dxg:GridControl>  
    <mvvm:Interaction.Behaviors>  
        <local:GridUpdateService />  
    </mvvm:Interaction.Behaviors>  
</dxg:GridControl>  
...

Access the service at the View Model level. If you inherit your View Model class from ViewModelBase, you can access the service as follows:

C#
public class ViewModel : ViewModelBase {  
    //...  

    public IGridUpdateService GridUpdateService { get { return GetService<IGridUpdateService>(); } }  

    void TimerCallback(object state) {  
        lock(SyncRoot) {  
            if(GridUpdateService != null) {  
                GridUpdateService.BeginUpdate();  
                foreach(DataItem item in Source) {  
                    item.Value = random.Next(100);  
                }  
                GridUpdateService.EndUpdate();  
            }  
        }  
    }  
}

Files to Look At

GridUpdateService.cs (VB: GridUpdateService.vb)
MainWindow.xaml (VB: MainWindow.xaml)
ViewModel.cs (VB: ViewModel.vb)

Documentation

Refer to the following topics for information on how to access a service in the ViewModel:

More Examples

How to Call the BeginDataUpdate and EndDataUpdate Methods at the View Model Level

Does this example address your development requirements/objectives?

(you will be redirected to DevExpress.com to submit your response)

Example Code

GridUpdateService.cs(vb)

C#
VB.NET

C#
using DevExpress.Xpf.Grid;
using System;
using System.Windows;
using DevExpress.Mvvm.UI;

namespace DXGridThreads {
    public interface IGridUpdateService {
        void BeginUpdate();
        void EndUpdate();
    }

    public class GridUpdateService : ServiceBase, IGridUpdateService {
        GridControl GridControl => AssociatedObject as GridControl;

        public void BeginUpdate() {
            Dispatcher.Invoke(new Action(() => {
                if (GridControl != null) {
                    GridControl.BeginDataUpdate();
                }
            }));
        }

        public void EndUpdate() {
            Dispatcher.Invoke(new Action(() => {
                if (GridControl != null) {
                    GridControl.EndDataUpdate();
                }
            }));
        }
    }
}

Visual Basic
Imports DevExpress.Xpf.Grid
Imports System
Imports DevExpress.Mvvm.UI

Namespace DXGridThreads

    Public Interface IGridUpdateService

        Sub BeginUpdate()

        Sub EndUpdate()

    End Interface

    Public Class GridUpdateService
        Inherits ServiceBase
        Implements IGridUpdateService

        Private ReadOnly Property GridControl As GridControl
            Get
                Return TryCast(AssociatedObject, GridControl)
            End Get
        End Property

        Public Sub BeginUpdate() Implements IGridUpdateService.BeginUpdate
            Dispatcher.Invoke(New Action(Sub()
                If GridControl IsNot Nothing Then
                    GridControl.BeginDataUpdate()
                End If
            End Sub))
        End Sub

        Public Sub EndUpdate() Implements IGridUpdateService.EndUpdate
            Dispatcher.Invoke(New Action(Sub()
                If GridControl IsNot Nothing Then
                    GridControl.EndDataUpdate()
                End If
            End Sub))
        End Sub
    End Class
End Namespace

MainWindow.xaml

XAML
<Window x:Class="DXGridThreads.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
        xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
        xmlns:local="clr-namespace:DXGridThreads"
        xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
        Title="MainWindow"
        Width="525"
        Height="350">
    <Window.DataContext>
        <local:ViewModel />
    </Window.DataContext>
    <dxg:GridControl AutoGenerateColumns="AddNew" ItemsSource="{Binding Source}">
        <dxmvvm:Interaction.Behaviors>
            <local:GridUpdateService />
        </dxmvvm:Interaction.Behaviors>
    </dxg:GridControl>
</Window>

ViewModel.cs(vb)

C#
VB.NET

C#
using DevExpress.Mvvm;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Threading;

namespace DXGridThreads {
    public class DataItem : BindableBase {
        public string Name { get { return GetValue<string>(); } set { SetValue(value); } }
        public int Value { get { return GetValue<int>(); } set { SetValue(value); } }
    }

    public class ViewModel : ViewModelBase {
        public ObservableCollection<DataItem> Source { get; set; }
        public IGridUpdateService GridUpdateService { get { return GetService<IGridUpdateService>(); } }

        public ViewModel() {
            timer = new Timer(TimerCallback, null, 1000, 1000);
            Source = new ObservableCollection<DataItem>(GetData());
        }

        static object SyncRoot = new object();
        Timer timer;
        Random random = new Random();

        void TimerCallback(object state) {
            lock(SyncRoot) {
                if(GridUpdateService != null) {
                    GridUpdateService.BeginUpdate();
                    foreach(DataItem item in Source) {
                        item.Value = random.Next(100);
                    }
                    GridUpdateService.EndUpdate();
                }
            }
        }

        static IEnumerable<DataItem> GetData() {
            for(var i = 0; i < 100; ++i) {
                yield return new DataItem() { Name = $"Name {i}", Value = i };
            }
        }
    }
}

Visual Basic
Imports DevExpress.Mvvm
Imports System
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Imports System.Threading

Namespace DXGridThreads

    Public Class DataItem
        Inherits BindableBase

        Public Property Name As String
            Get
                Return GetValue(Of String)()
            End Get

            Set(ByVal value As String)
                SetValue(value)
            End Set
        End Property

        Public Property Value As Integer
            Get
                Return GetValue(Of Integer)()
            End Get

            Set(ByVal value As Integer)
                SetValue(value)
            End Set
        End Property
    End Class

    Public Class ViewModel
        Inherits ViewModelBase

        Public Property Source As ObservableCollection(Of DataItem)

        Public ReadOnly Property GridUpdateService As IGridUpdateService
            Get
                Return GetService(Of IGridUpdateService)()
            End Get
        End Property

        Public Sub New()
            timer = New Timer(AddressOf TimerCallback, Nothing, 1000, 1000)
            Source = New ObservableCollection(Of DataItem)(GetData())
        End Sub

        Private Shared SyncRoot As Object = New Object()

        Private timer As Timer

        Private random As Random = New Random()

        Private Sub TimerCallback(ByVal state As Object)
            SyncLock SyncRoot
                If GridUpdateService IsNot Nothing Then
                    GridUpdateService.BeginUpdate()
                    For Each item As DataItem In Source
                        item.Value = random.Next(100)
                    Next

                    GridUpdateService.EndUpdate()
                End If

            End SyncLock
        End Sub

        Private Shared Iterator Function GetData() As IEnumerable(Of DataItem)
            Dim i = 0
            While i < 100
                Yield New DataItem() With {.Name = $"Name {i}", .Value = i}
                Interlocked.Increment(i)
            End While
        End Function
    End Class
End Namespace

DevExpress Support Team

last modified 7 years ago

Modified: November 9, 2017 11:13 AM

Platform: WPF

Product: DXGrid and DXTreeList for WPF

Disclaimer: The information provided on DevExpress.com and affiliated web properties (including the DevExpress Support Center) is provided "as is" without warranty of any kind. Developer Express Inc disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. Please refer to the DevExpress.com Website Terms of Use for more information in this regard.

Confidential Information: Developer Express Inc does not wish to receive, will not act to procure, nor will it solicit, confidential or proprietary materials and information from you through the DevExpress Support Center or its web properties. Any and all materials or information divulged during chats, email communications, online discussions, Support Center tickets, or made available to Developer Express Inc in any manner will be deemed NOT to be confidential by Developer Express Inc. Please refer to the DevExpress.com Website Terms of Use for more information in this regard.