ApplicationThemeHelper.PreloadAsync(Func<UserControl>) Method

Asynchronously preloads theme resources for the view specified by the UserControl and allows you to initialize this view before the preload.

Namespace: DevExpress.Xpf.Core

Assembly: DevExpress.Data.Desktop.v23.2.dll

NuGet Packages: DevExpress.Data.Desktop, DevExpress.ExpressApp.Win.Design

Declaration

C#

public static Task PreloadAsync(
    Func<UserControl> createAction
)

VB.NET

Public Shared Function PreloadAsync(
    createAction As Func(Of UserControl)
) As Task

Parameters

Name	Type	Description
createAction	Func<UserControl>	A function that initializes the preloaded UserControl.

Returns

Type	Description
Task	A task that allows you to asynchronously preload theme resources.

Remarks

Note

The PreloadAsync method allows you to preload lightweight theme resources only. Use the PreloadThemeResourceAsync method instead to asynchronously preload regular theme resources.

Use this method if the preloaded view is “lightweight” and you populate it with controls at runtime or based on a parameter.

The following code sample calls the MyControl.Populate() method and asynchronously preloads resources for the MyControl after the method is executed:

App.xaml.cs

using DevExpress.Xpf.Core;
using System.Windows;

public partial class App : Application {
    static App() {
        CompatibilitySettings.UseLightweightThemes = true;
    }
    protected override async void OnStartup(StartupEventArgs e) {
        base.OnStartup(e);
        await ApplicationThemeHelper.PreloadAsync(() => new MyControl().Populate());
    }
}

App.xaml.vb

Imports DevExpress.Xpf.Core
Imports System.Windows

Public Partial Class App
    Inherits Application

    Private Shared Sub New()
        CompatibilitySettings.UseLightweightThemes = True
    End Sub

    Protected Overrides Async Sub OnStartup(ByVal e As StartupEventArgs)
        MyBase.OnStartup(e)
        Await ApplicationThemeHelper.PreloadAsync(Function() New MyControl().Populate())
    End Sub
End Class

Refer to the following help topic for more information: Preload Theme Resources.