WPF

public static readonly DependencyProperty ProjectProperty =
            DependencyProperty.Register("Project",
            typeof(ProjectEntity),
            typeof(PurchaseOrderView),
            new PropertyMetadata(null, new PropertyChangedCallback(OnProjectChanged)));

public ProjectEntity Project
{
    get { return (ProjectEntity)GetValue(ProjectProperty); }
    set { SetValue(ProjectProperty, value); }
}

private static void OnProjectChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    PurchaseOrderView control = (PurchaseOrderView)d;
    control.LoadPurchaseOrders();
}
<h1>endregion</h1>

<Style.Triggers>
    <MultiDataTrigger>
        <MultiDataTrigger.Conditions>
            <Condition Binding="{Binding AreFieldsEnabled}" Value="True" />
            <Condition Binding="{Binding CanUserEdit}" Value="True" />
        </MultiDataTrigger.Conditions>
        <MultiDataTrigger.Setters>
            <Setter Property="IsEnabled" Value="True" />
        </MultiDataTrigger.Setters>
    </MultiDataTrigger>
</Style.Triggers>

Private Sub bwstartup_DoWork(sender As Object, e As DoWorkEventArgs) Handles bwstartup.DoWork
        'load some data
        LoadData()
        bwstartup.ReportProgress(15)
        LoadData2()  
        bwstartup.ReportProgress(20)

        Dispatcher.Invoke(Sub() LoadUserControl())
        bwstartup.ReportProgress(30)
       
        Dispatcher.Invoke(Sub() LoadUserControl2())
        bwstartup.ReportProgress(40)
    End Sub

    Private Sub bwstartup_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles bwstartup.ProgressChanged
        loadingbar.Value = e.ProgressPercentage
    End Sub

    Private Sub bwstartup_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs) Handles bwstartup.RunWorkerCompleted

    End Sub