Page Loaded event
<Page x:Class="WpfApplication1.StartPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Loaded="Init" /> //File:Window.xaml.cs using System; using System.Windows; using System.Windows.Controls; using System.Windows.Navigation; namespace WpfApplication1 { public partial class StartPage : Page { TextBlock txtElement; StackPanel rootPanel; Button aButton; void Init(object sender, EventArgs args) { rootPanel = new StackPanel(); txtElement = new TextBlock(); aButton = new Button(); aButton.Content = "Press me"; rootPanel.Children.Add(txtElement); rootPanel.Children.Add(aButton); } } }