DispatcherService Class

A UI service that allows you to use the DispatcherQueue to perform actions in a ViewModel.

Namespace: DevExpress.WinUI.Core

Assembly: DevExpress.WinUI.Core.v22.1.dll

NuGet Package: DevExpress.WinUI

Declaration

C#

public class DispatcherService :
    UIServiceBase,
    IDispatcherService

VB.NET

Public Class DispatcherService
    Inherits UIServiceBase
    Implements IDispatcherService

Remarks

Run Demo: UI Services Module in the WinUI MVVM Demo

The following code sample adds DispatcherService to the view:

XAML

<UserControl
    xmlns:dx="using:DevExpress.WinUI.Core"
    xmlns:ViewModel="using:WinUIApp.ViewModel" ...>
    <UserControl.DataContext>
        <ViewModel:ViewModel />
    </UserControl.DataContext>
    <dx:Interaction.Behaviors>
        <dx:DispatcherService />
    </dx:Interaction.Behaviors>
    <!-- Or: -->
    <dx:Interaction.Behaviors>
        <dx:DispatcherService ServiceClient="{x:Bind ViewModel}"/>
    </dx:Interaction.Behaviors>
        ...
</UserControl>

Use the InvokeAsync method to perform the required actions.

C#

public class ViewModel : ViewModelBase {
    protected IDispatcherService DispatcherService => GetUIService<IDispatcherService>();
    ...
    async void Calc() {
        ...
        await DispatcherService.InvokeAsync(() => { ... });
        ...     
    }
}

VB.NET

Public Class ViewModel
    Inherits ViewModelBase

    Protected ReadOnly Property DispatcherService() As IDispatcherService
        Get
            Return GetUIService(Of IDispatcherService)()
        End Get
    End Property
    '...
    Private Async Sub CalcCore()
        '...
        Await DispatcherService.InvokeAsync(Sub()
            ...
        End Sub)
        '...
    End Sub
    '...
End Class

Implements

IDispatcherService

Inheritance

Object

DependencyObject

Behavior

Behavior<FrameworkElement>

UIServiceBase<FrameworkElement>

UIServiceBase

DispatcherService